Re: [time-nuts] suggestions on getting 24 Mhz ?

[Mark Spencer]

Thanks Tim.

All the best

Mark Spencer

m...@alignedsolutions.com
604 762 4099

> On May 9, 2018, at 5:38 PM, Tim Tuck <t...@skybase.net> wrote:
> 
> Hi Mark,
> 
> this is a product of Glen VK1XX.
> he will have a website with eCommerce up soon and when that happens I will
> announce it to the list
> Regards
> Tim
> 
>> On Wed, 9 May 2018 at 10:43, Mark Spencer <m...@alignedsolutions.com> wrote:
>> 
>> Hi would anyone be able to point me (off list) in the direction of a bit
>> more information re this device ?
>> 
>> Many thanks
>> 
>> Mark S
>> 
>> m...@alignedsolutions.com
>> 604 762 4099
>> 
>>> On May 8, 2018, at 12:15 AM, Tim Tuck <t...@skybase.net> wrote:
>>> 
>>> Hi Pete,
>>> 
>>> You probably want this...
>>> 
>>> https://github.com/glenenglishgithub/anylockerFS
>>> 
>>> 
>>> Lots of VK's are lining up for the first run of boards to lock their
>> radios.
>>> 
>>> regards
>>> 
>>> Tim
>>> 
>>>> On 11/04/2018 8:00 PM, Pete Lancashire wrote:
>>>> Needed for SDR project as external clock source.
>>>> 
>>>> -pete
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> -- 
> 
> -- 
> 
> VK2XAX :: QF56if23 :: BMARC :: WIA :: AMSATVK
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Re: [time-nuts] suggestions on getting 24 Mhz ?

[Mark Spencer]

Hi would anyone be able to point me (off list) in the direction of a bit more 
information re this device ?

Many thanks 

Mark S

m...@alignedsolutions.com
604 762 4099

> On May 8, 2018, at 12:15 AM, Tim Tuck  wrote:
> 
> Hi Pete,
> 
> You probably want this...
> 
> https://github.com/glenenglishgithub/anylockerFS
> 
> 
> Lots of VK's are lining up for the first run of boards to lock their radios.
> 
> regards
> 
> Tim
> 
>> On 11/04/2018 8:00 PM, Pete Lancashire wrote:
>> Needed for SDR project as external clock source.
>> 
>> -pete
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Re: [time-nuts] nuts about position

[Mark Spencer]

This link seems to provide an overview of Differential GPS and some related 
techniques.  

https://www.e-education.psu.edu/geog862/node/1834

Building a system along these lines from "auction site purchases" and home 
brewed computer code might be a fun project but one would presumably need an 
accurately surveyed starting point.


Mark Spencer

m...@alignedsolutions.com
604 762 4099

> On Apr 25, 2018, at 8:06 AM, George Watson <wat...@sierracmp.com> wrote:
> 
> Create your own DGPS?
> 
> Trimble is good at this.
> 
> George K. Watson
> K0IW
> 
>> On Apr 25, 2018, at 10:56 AM, Tom Van Baak <t...@leapsecond.com> wrote:
>> 
>> List -- I had a recent query by a researcher who would like to pinpoint the 
>> location of his telescope(s) within 0.3 meters. Also (he must be a true 
>> scientist) he wants to do this on-the-cheap. He may have timing requirements 
>> as well, but that's another posting.
>> 
>> So I toss the GPS question to the group. Surely some of you have crossed the 
>> line from precise time to precise location?
>> 
>> How easy, how cheap, how possible is it to obtain 0.3 m accuracy in 3D 
>> position?
>> 
>> When we run our GPSDO in survey mode how accurate a position do we get after 
>> an hour, or even 24 or 48 hours? And here I mean accurate, not stable. Have 
>> any of you compared that self-reported, self-survey result against an 
>> independently measured professional result or known benchmark?
>> 
>> Do you know if cheap ublox 5/6/7/8 series receivers are capable of 1 foot 
>> accuracy given enough time?
>> 
>> If not, what improvement would -T models and RINEX-based web-service 
>> post-processing provide?
>> 
>> It that's still not close enough to 0.3 m, is one then forced to use more 
>> expensive multi-frequency (L1/L2) or multi-band (GPS, GLONASS, Galileo) to 
>> achieve this level of precision? If so, how cheaply can one do this? Or is 
>> the learning curve more expensive than just hiring an survey specialist to 
>> make a one-time cm-level measurement for you?
>> 
>> Something tells me 1 foot accuracy in position is possible and actually 
>> easier than 1 ns accuracy in time. I'm hoping some of you can help recommend 
>> solution(s) to the researcher's question or shed light on this interesting 
>> challenge.
>> 
>> Thanks,
>> /tvb
>> 
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Re: [time-nuts] TV Signals as a frequency reference

[Mark Spencer]

Yes I actually purchased two such devices from Ebay a while back.   (They 
contained nice PRS10 Rb oscillators.)

Mark Spencer

Aligned Solutions Co.
m...@alignedsolutions.com
604 762 4099

> On Mar 31, 2018, at 12:09 PM, Ruslan Nabioullin <rnabioul...@gmail.com> wrote:
> 
>> On Sat, Mar 31, 2018 at 9:38 AM, Bob kb8tq <kb...@n1k.org> wrote:
>> You probably would do better to build a gizmo to pull timing off you local 
>> cell towers.
>> The hardware to do it is relatively well documented. As long as you are 
>> careful about
>> which system you use, the timing should be GPS based ….
> 
> Commercially-made cellular reference receivers obviously do exist (IT
> folks tend to love them due to there being no need for outdoor antenna
> requirements).
> 
> -Ruslan
> 
> -- 
> Ruslan Nabioullin
> Wittgenstein Laboratories
> rnabioul...@gmail.com
> (508) 523-8535
> 50 Louise Dr.
> Hollis, NH 03049
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Re: [time-nuts] OCXO Vectron 218Y44442

[Mark Spencer]

I've experienced this with products with simple crystal oscillators.   (Ie. Tap 
or bang the unit to get the oscillator to start oscillating.)

Mark Spencer

m...@alignedsolutions.com
604 762 4099

> On Oct 16, 2017, at 1:10 PM, Vlad <t...@patoka.org> wrote:
> 
> 
> Hello,
> 
> I am wandering if anybody observe the behavior for OCXO, when its stop to 
> reproduce the signal, and the only way to return it back to business is 
> little mechanical stress.
> 
> I have TWO of such OCXO. One of them is Austron 11.2 Mhz. And another one is 
> Vectron model 218Y4442 9.8304Mhz
> 
> In case with Vectron, I even disassemble it (to whom who brave here is a 
> pictures):
> 
> http://www.patoka.ca/Vectron-218Y2/
> 
> Then as I connect it to the PS, I realize it start to reproduce the signal 
> again ! Before this it was nothing ! I tried different PS before to open this 
> "can" as a last resort.
> 
> For the Austron - I didn't disassemble it. Instead I just kick it a little 
> bit. And immediately after that, it start to produce the signal !
> 
> 
> -- 
> WBW,
> 
> V.P.
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Re: [time-nuts] GPS Antenna Feed Line Decision

[Mark Spencer]

Although not time nuts related I believe this document speaks to some of the 
practical issues...

http://www.slac.stanford.edu/cgi-wrap/getdoc/slac-pub-6297.pdf



Mark Spencer


m...@alignedsolutions.com

> On Sep 3, 2017, at 4:56 PM, Mark Sims <hol...@hotmail.com> wrote:
> 
> Real time nuts run phase stable cable (some well over $50 / foot) in climate 
> controlled ducts... which is all for nought unless you also climate control 
> the antenna.Which is all standard practice for precision geodesy.  Try to 
> keep it all with a milli-Kelvin or two.  Oh, and don't forget about Lord 
> Kelvin's sinister  step-sisters, humidity and pressure.  We won't get into 
> all his second-order cousins.
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Re: [time-nuts] GPS Antenna Feed Line Decision

[Mark Spencer]

Hi.

The last time I looked at upgrading my GPS antenna feed line (I'm currently 
using RG58 style cable) I spent some time looking at the temperature vs 
propagation delay characteristics of various cables.

I also picked up a spool of cloned "LMR400 style" cable but ended up using that 
for my amateur radio hobby.  If I was going to throw more money at my Time Nuts 
GPS feed line I'd probably look for a "hard line" style cable with a favourable 
temperature vs propagation delay characteristic.   For a basic installation I 
expect I would just use RG6 style cable.

Good luck.

Mark S

m...@alignedsolutions.com
604 762 4099

> On Sep 3, 2017, at 9:57 AM, Clay Autery  wrote:
> 
> Thank you for your response.  Again, money is not the issue or
> priority.  Knowing that I am getting the best signal within reason (my
> reason   )
> Tangentially, you have provided me with the information I require.  As I
> do not know what I will hang off the end of that antenna in the future
> and I am in fact going to be doing some measurement/experimentation, I
> will use something better than RG-59 or RG-6 (even if it is only
> "better" in my opinion).
> 
> I am an incurable over-engineer... and this IS "Time NUTS" after all. 
> 
> 
> Thank to you AND to ALL who have made recommendations thusfar
> especially the ones with whom I disagree.  Those are the recommendations
> that keep me from completely abandoning rational decision-making.   grin>
> 
> 73,
> 
> __
> Clay Autery, KY5G
> MONTAC Enterprises
> (318) 518-1389
> 
>> On 9/2/2017 3:27 PM, Mark Sims wrote:
>> Cheap RG-59 cable coax is more than sufficient for 50 .. 150+ feet (unless 
>> you are doing geodetic level GPS work).  It is recommended by several GPSDO 
>> makers.  The 50/75 ohm mismatch is not an issue.  No need to waste money on 
>> fancy pants artisanal luxury coax.
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Re: [time-nuts] Trimble Thunderbolt no longer determines the correct date

[Mark Spencer]

Nice post Tom.  I was also wondering about the replacement hardware vs software 
patch issue.  Just speculation on my part but perhaps changing the software 
involves an extensive QA / test process, vs swapping out a piece of hardware ?  
 Again this is just pure speculation on my part.

Mark Spencer



On Aug 11, 2017, at 9:26 AM, Tom Van Baak <t...@leapsecond.com> wrote:

>> The E911 installation, in the news, is just one of several. Others are 
>> hospitals,
>> fire stations, etc. using different dispatch systems.
> 
> Hey, at least important things like mobile phones, ISP's, Google, Amazon, 
> FedEx and Starbucks aren't affected ;-)
> 
>> In a wide-area simulcast-overlap paging system, the transmitters in the same
>> coverage area are carefully set to all transmit at exactly the same time.
> 
> That's fine. And very clever. But why is this "life safety" system tied to 
> GPS, to a particular vendor, to a particular model of receiver (that clearly 
> states in the documentation that it has a 1024 week / 19.6 year window of 
> valid UTC times)?
> 
>> So to me "synchronizing transmitters” means the control system sends the
>> traffic out to all the transmitters (over satellite) and tells them all to 
>> hold the
>> messages in a buffer until “the big hand points straight up” or whatever data
>> command the system uses. (excuse the vernacular)
> 
> Exactly. In most of the precise timing world the "big hand" is the "top of 
> the second", or the so-called 1 PPS pulse. The idea is that all 1PPS agree 
> with each other, whether from a cesium clock, or WWVB receiver, or NTP, or 
> GPS (or any other GNSS system).
> 
> Since the paging system failed it sounds like it was synchronized to some 
> "hand" other than 1PPS. The rare GPS rollover events tend not to disrupt the 
> 1PPS output -- it is still perfectly aligned with UTC -- which is why almost 
> no one else worries about the recent TBolt episode, or any other GPS receiver 
> for that matter.
> 
>> The problems being experienced right now appear to be the interface of the 
>> ThunderBolt
>> with the Zetron Model 620 simulcast controller over TSIP. The Zetron box is 
>> also called
>> a “wireless data encoder.”
> 
> Ah, ok. So do you or anyone have contact within Zetron? The easy fix would be 
> for them to upgrade their firmware and send out a patch. Probably cheaper 
> than supplying new receivers from Trimble. I don't know; for us, a s/w fix is 
> easy compared to a h/w fix or a h/w swap-out. But in the real world, once 
> technicians have driven to a remote installation, maybe there's no real 
> difference between a s/w fix and a h/w swap.
> 
>> It is not our goal to blame a particular piece of equipment for this problem.
> 
> Right, no need to blame. I think many of us would just want to pinpoint the 
> root cause of the problem, out of engineering curiosity. By root cause I mean 
> actual schematics or lines of source code. It's always been my hope, after 
> every one of these widespread infrastructure events, that the actual source 
> code or design decisions be published eventually so that we can all learn 
> from it.
> 
>> The facts are the 1024 roll over happened and just about nobody in the paging
>> business knew it was coming.
> 
> Ok, now you know about GPS rollovers! Fun, isn't it? Leap seconds are fun too.
> 
> When the dust settles, you may want to look into the more general topic of 
> life safety infrastructure vs. free-from-the-sky time & frequency. These days 
> nanosecond precise time is cheaper than water -- but it's also fragile. A lot 
> has been written about this. It's both a wake-up call for naive vendors of 
> products based on GPS alone and also an opportunity for vendors who know how 
> to design and market resilient timing products.
> 
> /tvb
> 
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Re: [time-nuts] Power connectors continued

[Mark Spencer]

I hear what you are saying and basically agree with you.
  In my experience however phrases such as "25 pair amphenol connector" and "2 
pin Deutsch connector" have a commonly accepted meaning in the industries I 
have worked in over the years.   Putting these terms into Google brings up the 
items I expect to see which is admittedly a fairly subjective criteria.   I 
agree however there are more precise designations and that in many 
circumstances they should be used.  Sorry I don't remember what they were / are 
and rarely needed to use them in practice.  I'm more or less retired and what 
ever memories I had of specific connector part numbers beyond the standard 
terms used in the industries I have worked in have largely faded.

As this is a hobby for me I'm disinclined to look up specific part numbers but 
can appreciate that others may wish to do so and welcome the additional detail.

I believe there is some benefit to further discussions along these lines 
(perhaps though there should be a connector nuts list.)

>From a time nuts perspective I expect there could be healthy discussion to be 
>had about the relative merits of BNC vs SMA connectors for example.

The issue of power connectors with locking devices is also in my view quite 
relevant to time nuts.   The dialogue vis a vis power pole connectors has also 
been one of the best I have ever seen on the Internet. 


Thanks all

Mark Spencer

m...@alignedsolutions.com


> On Jun 22, 2017, at 3:54 PM, Arnold Tibus <arnold.ti...@gmx.de> wrote:
> 
> 
> Hello,
> 
> I can second Magnus and want to throw in some more details.
> Cannon, Deutsch, Bendix, Souriau, Matrix, Amphenol,  etc. etc. are (big)
> companies manufacturing all kind of connectors and are  n o t  connector
> type designations! Important are the type numbers of the manufacturer or
> higher level specification numbers.
> We used in the aircraft and spacecraft business naturally the military
> (MS-) numbers listed in the MIL-QPL (or eg. for Spacelab with GSFC spec.
> no). Most types of connectors are under these numbers available from
> different manufacturers, of course with different manufacturer in house
> part numbers. Attention: the 'same' connectors may be bought w/o the
> Mil.-spec. sheets with somewhat lesser quality. Important details are
> the max. mating number, the contact resistance (e.g. 20 mOhm) and the
> max. continuous current, max. Voltage, vibration resistance and
> reliability etc.  Of course, this makes good connectors somewhat
> 'expensive'. Hirel and non-magnetic gold plated D- subminiture type
> connectors do survive e.g. the rocket launch phase (high vibrations),
> vacuum and low temperatures and are still used for space projects.
> 
> The D-sub series of connectors was introduced by Cannon in 1952. They
> are still available as standard, hirel, and non-magnetic versions. The
> contacts were machined contacts forcrimping or soldering connection and
> made of massive copper with gold finish. (more see e.g.
> https://en.wikipedia.org/wiki/D-subminiature). Example for the standard
> 9 pin connector designation (crimp): DEMAM-9S and DEMAM-9P. Today are a
> big number of companies producing equivalent types. Cheap ones are
> equipped with contacts made of sheetmetal. Nobody should expect then the
> same spec. values as reliability, mating numbers, contact power rating etc.
> It is up to the designer of a product to be informed and select the
> right quality device for his product ...
> 
> I hope I could enlight a bit the connector selection and nomenclature point.
> 
> regards, 73
> 
> Arnold, DK2WT
> 
> 
> 
>> Am 22.06.2017 um 21:10 schrieb Magnus Danielson:
>> Hi,
>> 
>> The second connect has been called "Cannon" and XLR, and is not
>> generally recogniced as XLR, which is the product range name.
>> 
>> Naming of the first connector as "Cannon" is at least for me and many
>> others confusing. This is a good example how vendor name for a
>> connector type is not a good thing. The first connector is a circular
>> MIL-STD connector (don't remember the correct notation), and this is a
>> product available from ITT Cannon as well as AMP.
>> 
>> Cheers,
>> Magnus
>> 
>>> On 06/22/2017 08:42 PM, Mark Spencer wrote:
>>> Sorry if I have caused any un due confusion thru my perhaps incorrect
>>> use of the terms "cannon" and "XLR."
>>> The green connector with 4 separate female contacts is what I
>>> perhaps in correctly referred to as a "cannon" connector.  The silver
>>> connector with 3 separate female contacts was what I perhaps
>>> incorrectly referred to as a "XLR" connector.
>>> 
>>>

Re: [time-nuts] Power connectors continued

[Mark Spencer]

There seem to be many variations in colloquial naming in different regions and 
industries.   Part of the reason I prefer to deal with local vendors with a 
parts counter is to be able to more or less confirm that connectors match / 
mate properly prior to purchasing them.  

All the best.

Mark Spencer


m...@alignedsolutions.com


> On Jun 22, 2017, at 12:10 PM, Magnus Danielson <mag...@rubidium.dyndns.org> 
> wrote:
> 
> Hi,
> 
> The second connect has been called "Cannon" and XLR, and is not generally 
> recogniced as XLR, which is the product range name.
> 
> Naming of the first connector as "Cannon" is at least for me and many others 
> confusing. This is a good example how vendor name for a connector type is not 
> a good thing. The first connector is a circular MIL-STD connector (don't 
> remember the correct notation), and this is a product available from ITT 
> Cannon as well as AMP.
> 
> Cheers,
> Magnus
> 
>> On 06/22/2017 08:42 PM, Mark Spencer wrote:
>> Sorry if I have caused any un due confusion thru my perhaps incorrect use of 
>> the terms "cannon" and "XLR."
>> The green connector with 4 separate female contacts is what I perhaps in 
>> correctly referred to as a "cannon" connector.  The silver connector with 3 
>> separate female contacts was what I perhaps incorrectly referred to as a 
>> "XLR" connector.
>> 
>> Both were in use in my lab powering time nuts gear.
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> Mark Spencer
>> 
>> m...@alignedsolutions.com
>> 
>> 
>> 
>> ___
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[time-nuts] Power connectors continued

[Mark Spencer]

Sorry if I have caused any un due confusion thru my perhaps incorrect use of 
the terms "cannon" and "XLR."
 The green connector with 4 separate female contacts is what I perhaps in 
correctly referred to as a "cannon" connector.  The silver connector with 3 
separate female contacts was what I perhaps incorrectly referred to as a "XLR" 
connector. 

Both were in use in my lab powering time nuts gear.










Mark Spencer

m...@alignedsolutions.com

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Re: [time-nuts] Anderson PowerPole (was Charles Wenzel GPSDO)

[Mark Spencer]

Good point and for hobby use (ie. Amateur radio, time nuts pursuits etc.) I can 
see this being a consideration.   

That being said in my prior day jobs where we had various solar panel, battery, 
charge controller, AC powered charger,  load combinations etc.. as far as I can 
recall I never encountered equipment that  allowed for that  specific use case 
via hermaphroditic connectors.  It is still a good point however.

Mark Spencer

m...@alignedsolutions.com
604 762 4099

> On Jun 22, 2017, at 9:25 AM, Richard (Rick) Karlquist <rich...@karlquist.com> 
> wrote:
> 
> No one has brought up the issue of hermaphrodicity, so
> I will.  Only PP's are hermaphroditic.  Why does this
> matter?  It matters in the case of a battery.  A battery
> is both a power source and a power sink.  In the PP
> system, you can make a 3 way connection between a
> power source, a power sink, and a battery, where
> the battery float charges on the 12V bus it is connected
> to.  Non-hermaphroditic connector schemes do not allow
> a 3 way connection.  Attempting to do a work around
> would require fabricating a special 3 way harness,
> which would not be idiot proof.
> 
> This is the fundamental reason for using PP's.
> 
> If you never use batteries, then all the other
> gendered connector schemes are fair game.
> 
> As far as connectors pulling out is concerned:
> use a cable clamp to strain relieve the connection.
> 
> Rick N6RK
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Re: [time-nuts] Anderson PowerPole (was Charles Wenzel GPSDO)

[Mark Spencer]

I believe the "AMP" connectors you are referring to are what I would call a 
"Cannon" connector.   A good choice for that application IMHO.

Mark Spencer

m...@alignedsolutions.com


> On Jun 22, 2017, at 6:47 AM, Bob Bownes <bow...@gmail.com> wrote:
> 
> Right Tool for the Job. 
> 
> I use barrel connectors when I _want_ the cord to come out when the unit 
> falls off the shelf rather than dangle by the power cable. 
> 
> Locking Molex, or, far better, locking AMP connections when I want the unit 
> to hang by the cord when necessary. 
> 
> We've gone to 9 pin circular locking AMP connectors for rotors on our 2x 
> /year ham radio contest set up on the mountain (take a look for W2SZ / MGEF). 
> Waterproof (not water tight), sturdy, impossible to misalign. And 40' of 
> cable can hang from one for a few minutes if need be. 
> 
> 
> 
> 
>> On Jun 22, 2017, at 09:03, Clint Jay <cjaysh...@gmail.com> wrote:
>> 
>> Heh, I was thinking just that when I typed it. They're almost inverted, the
>> pegs are on the plug and the slots are on the socket, the ones I've seen
>> aren't spiral slots, you have to fully engage the plug before you twist.
>> 
>> I like PowerPoles, I like barrel connections, as with so many things it's
>> all about the application, choose the one that works for you.
>> 
>> 
>> 
>>> On 22 Jun 2017 1:53 pm, "Bob Bownes" <bow...@gmail.com> wrote:
>>> 
>>> Locking barrel connectors...
>>> 
>>> Aren't those called BNCs? ;)
>>> 
>>> In one of my other lives, I see Power Poles used in a very life critical
>>> application. They are used to connect pads to Automatic External
>>> Defibrillators. In that application, the two poles (15A, red & white) are
>>> glued together rather than using the roll pin.
>>> 
>>> Bob
>>> 
>>>> On Jun 22, 2017, at 08:29, Clint Jay <cjaysh...@gmail.com> wrote:
>>>> 
>>>> It is possible to get hold of locking barrel connectors, they insert as
>>>> normal and a quarter twist fastens them in place. The plugs and sockets
>>> are
> 
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Re: [time-nuts] Anderson PowerPole (was Charles Wenzel GPSDO)

[Mark Spencer]

This good information.  Thanks

Mark Spencer

m...@alignedsolutions.com


> On Jun 22, 2017, at 7:27 AM, Mike Seguin <n1...@burlingtontelecom.net> wrote:
> 
> NL2 etc 40A
> 
> They typically run about $3 per connector. I use them on high power Solid 
> State amps. (VHF and up)
> 
> Mike
> 
>> On 6/22/2017 10:10 AM, Clay Autery wrote:
>> OK I was wrong...  Attila was right.  IF we are going to talk
>> alternatives and not simply bash PP cons, then I'm in.  Always up for a
>> bit of over-engineering.  
>> The speakon connectors are interesting...
>> Do you have a favorite series/model, Mike?
>> __
>> Clay Autery, KY5G
>>> On 6/22/2017 7:40 AM, Mike Seguin wrote:
>>> For anything critical, I use these connector from the professional
>>> sound industry.
>>> 
>>> http://www.neutrik.com/en/speakon/
>>> 
>>> Mike
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> -- 
> 
> 73,
> Mike, N1JEZ
> "A closed mouth gathers no feet"
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Re: [time-nuts] Anderson PowerPole (was Charles Wenzel GPSDO)

[Mark Spencer]

For amateur radio use I've never perceived power poles as offering enough of an 
advantage over most other power connectors to make me willing to change my 
other connectors for power poles.  I do own some equipment that came with 
factory installed power pole connectors and I'm generally ok with how they 
work.   Some other amateur radio operators have expressed surprise at my 
extensive use of non power pole connectors and the use of power poles does seem 
common in the amateur radio world.

For time nuts and amateur radio use I've been quite happy with the multi pin 
circular "cannon" style connectors.  That would be my typical choice for a 
"high end" power connector for my various hobbies.  At the "low end" I'm happy 
with two pin "trailer" style connectors but in my experience they are generally 
only available in "pig tail" form.   Both the "cannon" style and "trailer" 
style connectors are readily available to me  as "over the counter" items which 
plays a major role in my affinity towards them.   

Where I used to work "Deutch" connectors were very popular and those are also 
available to me as an "over the counter" item.  I expect I'll start using those 
at some point as well and will probably switch out the bulk of my "trailer" 
style connectors for Detch connectors.

I can also see some merit in using XLR style connectors in some applications.   
I strongly dislike the use of "phono plugs" and PL259 connectors for power 
supply applications.  

All the best 

Mark Spencer

m...@alignedsolutions.com


> On Jun 22, 2017, at 5:57 AM, Wes <w...@triconet.org> wrote:
> 
> Hi Tom,
> 
> I said I use PPs but I don't really like them.  If you use a pair as a cable 
> splice then yes, you can tie them together, but in the specific case I 
> referred to, the connection on Elecraft radios, the mate is sticking out the 
> back of a panel and it's impossible to knot the cable or use a zip tie.  I am 
> certainly not the only one who has had issues with this.  And lest I be 
> called an idiot, this is with a factory assembled and supplied pigtail.
> 
> Regards,
> 
> Wes
> 
> 
>> On 6/22/2017 12:19 AM, Tom Van Baak wrote:
>> Wes, Don,
>> 
>> I am quite surprised at the negative reaction to Anderson Power Pole 
>> connectors. I have found them the best DC connector out there. I have used 
>> them for a decade or two for all my DC feeds and have never had a problem: 
>> in my home lab, my car, even for my laptop charger. They are inexpensive, 
>> reliable, genderless (hermaphroditic) and easy to crimp. I use them for my 
>> 5V, 12V, 24V, and 48V supplies as well as my DC backup systems.
>> 
>> What on earth are you doing with them that causes them to disconnect? I 
>> mean, they are not meant for towing or lifting or rappelling. For critical 
>> applications there is a plastic gizmo that keeps them mated; or just use a 
>> square or figure 8 knot on the cables.
>> 
>> /tvb
> 
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Re: [time-nuts] WTB: GPSDO

[Mark Spencer]

Hi:

Bob's comment about adjusting an oscillator from time to time aligns well with 
my limited experience in the time nuts hobby.Once I realized that in 
practice my better OCXO's were typically more than stable enough for my 
intended uses things became much simpler.   I also realized that I could 
utilize my collection of time interval counters to compare my chosen reference 
to other references (including a GPSDO) while also comparing the chosen 
reference to the "Device Under Test."  I realize this isn't likely an approach 
that a commercial lab would use but for my hobby use it seems to work ok for me.

I've more or less shelved my plans to discipline one of my high end OCXO's via 
a home brew GPSDO scheme.

Mark Spencer


> On Mar 14, 2017, at 5:24 PM, Bob Camp <kb...@n1k.org> wrote:
> 
> Hi
> 
> 
>> On Mar 14, 2017, at 6:33 PM, Tim Lister <lister...@gmail.com> wrote:
>> 
>> On Fri, Mar 10, 2017 at 2:35 PM, Chris Albertson
>> <albertson.ch...@gmail.com> wrote:
>>> A GPSDO is not hard to make.  All you need is some way to compare the
>>> phase of two signals, an XOR gate can do that.  Then a small $2
>>> process moves the control voltage on the crystal.I tried one to
>>> build the simplest GPSDO that could still work.   Got the parts count
>>> down to about four or five and the cost well under $10 plus the OXO
>>> which was about $20.  The simplest dumb one I could make keeps about
>>> e-10.  Not great but enough for many uses.   I compared to my
>>> Thunderbolt and I could see the phase advance and retreat.  Just a
>>> little most sophistication and I likely could do much better but my
>>> goal was to prove to myself that a GPSDO could be build VERY simply
>>> with cheap parts
>> 
>> Hi Chris, that's good news that a GPSDO is that easy to make (at least
>> a basic one) as that is exactly my medium term plan !
> 
> Actually it’s much easier. Just put a DVM on the XOR once a week and 
> adjust your oscillator with a screwdriver. It saves *lots* of time and money.
> 
> Bob
> 
> 
>> The issue of
>> course is having something to test the newly built GPSDO against... I
>> got one of the rehoused Trimble UCCM-based GPSDOs off ebay a while ago
>> but haven't been super happy with it. It's quite a bit less sensitive
>> than more modern GPS receivers and it often struggles to get even 1
>> satellite with the indoor patch antenna. At one point both red alarm
>> LEDs came on and stayed on despite power cycles - I eventually fixed
>> that by taking it apart and finding and hitting a reset button on the
>> board. Currently although I can talk to the unit over serial and it
>> seems to respond, Lady Heather is not seeing any output from it.
>> 
>> Combined these things don't give me a great deal of confidence that
>> this unit will act as a stable master reference. I was wondering if a
>> second GPSDO like Russ linked to would work better (I have a ublox
>> LEA-6T GPS already which I plan to use as the basis of the homebuilt
>> GPSDO and it consistently sees many more satellites than the UCCM
>> with a similar indoor antenna)  or put the money to getting an outdoor
>> antenna mounted (don't feel happy drilling holes in the house myself)
>> by someone. Do 2 GPSDOs tell you much more or just that each is
>> different and you need a third to adjudicate ? (I can see a slippery
>> slope looming from here...)
>> 
>> Cheers,
>> Tim
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Re: [time-nuts] Smart Phone time display accuracy...?

[Mark Spencer]

>From occasional observations of my IPhone 5 using the emerald sequoia emerald 
>time application the "within 50 milliseconds" claim seems quite reasonable to 
>me.

Mark Spencer




> On Mar 16, 2017, at 12:31 PM, Chris Albertson <albertson.ch...@gmail.com> 
> wrote:
> 
> Apple Support claims "within 50 milliseconds of the definitive global
> time standard".  At least that is what Apple gives in their spec.
> 
> It might use difference source depending on which radios are enabled.
> The phone does have GPS and a cell network radio and both can be used
> for time.But on a phone these radios are powered up and down as
> needed.   I think best just to accept Apple's spec.
> 
> Again it would be fun to measure.  There is an API call to get the
> system time.  One could write a simple app to send this out
> 
> Harder to know the specs on Android as there are so many manufactures
> and versions and price points
> 
>> On Thu, Mar 16, 2017 at 10:06 AM, Mike Garvey <r3m...@verizon.net> wrote:
>> CDMA mobile telephony needs system synchronization to +/- 10 uS in order to 
>> smoothly handoff a moving client from one cell to the next. Most systems use 
>> GPS to maintain this 10 uS.  This says nothing about how bad it could get 
>> after that.
>> Mike
>> 
>> -Original Message-
>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Mike Baker
>> Sent: Wednesday, March 15, 2017 22:33
>> To: time-nuts@febo.com
>> Subject: [time-nuts] Smart Phone time display accuracy...?
>> 
>> Hello, Time-nutters--
>> 
>> Any thoughts on what the likely accuracy of smart phone time
>> displays might be?   I am thinking that the stacking of delays
>> along the path to its receive antenna plus any internal processing delays 
>> would accumulate to some unknown degree.  Any thoughts on this?
>> 
>> Mike Baker
>> *
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> 
> 
> 
> -- 
> 
> Chris Albertson
> Redondo Beach, California
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Re: [time-nuts] wifi with time sync

[Mark Spencer]

Sorry as this is perhaps a bit off topic but I've tried to make this somewhat 
time nuts relevant.

Over the years I found ping tests have worked quite well (at least on WAN 
links) to roughly measure network bandwidth.  When I used to visit remote sites 
with WAN links I would often perform several ping tests with different payload 
sizes, average the results for each payload size, then use the difference in 
ping times for different payload sizes to calculate the available WAN 
bandwidth.  The calculated bandwidth was typically close enough to the actual 
bandwidth that I was later asked to demonstrate this "procedure" by people who 
maintained the networks.   

It also worked fairly well on "wifi type" networks as well.

I do understand that ping traffic may or may not be handled differently than 
other network traffic but at least in my experience the results of ping tests 
were useful.   As usual the experience of others may differ and I can 
understand why this technique may not always work well.

To relate this somewhat to time nuts it might be of interest to collect this 
type of data and see how consistent the difference is for round trip times with 
pings with a small payload and a large payload over a given network path.   

One also needs to be aware of TCP Window sizes and allowable network packet 
sizes when picking the payload sizes for this type of test.

BTW I was shown this basic technique at an industry seminar a few decades ago 
but in my experience it seems to have fallen out of common use these days.

All the best
Mark Spencer


> On Jan 14, 2017, at 11:02 AM, Bob Camp <kb...@n1k.org> wrote:
> 
> Hi
> 
> 
>> On Jan 14, 2017, at 1:38 PM, Chris Albertson <albertson.ch...@gmail.com> 
>> wrote:
>> 
>> On Sat, Jan 14, 2017 at 7:46 AM, Bob Camp <kb...@n1k.org> wrote:
>> 
>>> Hi
>>> 
>>> Ok, what I see is that every few hours, I get a “rogue delay” on a single
>>> ping. How
>>> would NTP help me spot a single transit with a 250 ms round trip and
>>> identify the
>>> time it occured? Keep in mind that NTP is going to throttle back to a very
>>> low level
>>> of “chat” quite quickly…..
>> 
>> I don't understand about NTP throttling back? Yes it quickly figure out the
>> best poll interval to each of the configure reference clocks but that is a
>> good thing.  
> 
> Not a good thing if you want to check the link at least once a second and 
> keep 
> doing so for days and days. If the objective is to profile the timing 
> stability of 
> the WiFi link *and* catch all the stupid things that happen … you need a lot
> of data. There are things that happen at widely spaced intervals. Is a ping 
> the 
> best thing to use? Certainly not. There just aren’t a lot of other 
> candidates. 
> Indeed there can be such a thing as “to much data”, there is an ADEV thread
> going along about that. 
> 
> Bob
> 
>> You like those poll intervals to be as long as possible
>> 
>> It will tell you the TIME an event occurred with good accuracy.  Record the
>> ping delay and the ping's time of day in the file.  Then if you want to
>> compare files between different logs made on different computers you can
>> know that all the time stamps are comparable.  I assume you want to know
>> the cause so you'd have to look at logs from other devices on your network
>> 
>> Question: do something happen every hour to cause this or is that something
>> happening say every 13 seconds and sets in phase with the ping interval
>> every hour?
>> 
>> Audio over wifi depends on "buffering".  The data are sent in packets or
>> batches.  The device that actually plays the audio will keep as much as a
>> few seconds of data and request more when the buffer gets about 1/2 empty.
>> So delays over wifi are not important.   The re-timing is done on the
>> receiving end, likely using a cheap crystal.
>> 
>> Audio over USB, HDMI to fiber TOSLINK is packetized as well and buffered
>> and re-clocked at the receiving end.  The difference is the size of the
>> buffer.  If it is packetized then it must be buffered and rechecked, no way
>> out of that.
>> 
>> So yes it is "giant buffers".  The data sent does contain the format, how
>> many channels, the sample rate and so forth
> 
> … but If you are playing the sound out of multiple speakers scattered around 
> the 
> room *and* their only link is WiFi, time sync does matter. That’s what 
> started this
> thread in the first place. Milisecond sync isn’t good enough in this case. 
> You need
> microsecond level sync. 
> 
> Bob
> 
>> 
>>> 
>>> Whil

Re: [time-nuts] wifi with time sync

[Mark Spencer]

To add to this I'd be curious in knowing about easy PC based ways to measure 
network latencies / delays with microsecond accuracy vs millisecond accuracy.

The tools I used to use at work were generally designed for use on networks 
where millisecond resolution measurements made sense as a "figure of merit."

Best regards
Mark Spencer

Sent from my iPhone

> On Jan 13, 2017, at 12:35 PM, Bob Camp <kb...@n1k.org> wrote:
> 
> Hi
> 
> What standard protocol would you recommend I run from the command line on my 
> computer 
> to get a quick estimate of the timing lag and variablilty  on my particular 
> WiFi connection?
> 
> Bob
> 
>> On Jan 13, 2017, at 3:25 PM, John Hawkinson <jh...@mit.edu> wrote:
>> 
>> Can we please stop talking about pings?
>> 
>> Bob Camp <kb...@n1k.org> wrote on Fri, 13 Jan 2017
>> at 15:12:38 -0500 in <c88c78a6-a015-4dcc-9e23-394dc33a3...@n1k.org>:
>> 
>>> I’m sure you are right about the response time. Right now the
>>> variation is running almost 3 ms at one sigma on a ping so there is
>>> a lot to do simply to get the accuracy anywhere near 1 us.
> 
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Re: [time-nuts] TICC Timestamping / Time Interval Counter -- Available to Order

[Mark Spencer]

Thanks John.   I just placed an order.

All the best
Mark S
VE7AFZ

Sent from my iPhone

> On Dec 7, 2016, at 11:45 AM, John Ackermann N8UR  wrote:
> 
> I'm happy to report that TAPR is now accepting orders for the TICC 
> timestamping / time interval counter.  We've placed an order with the 
> contract manufacturer and expect to have finished product ready to ship 
> sometime in February.  The TICC system will include the TICC shield mounted 
> on an Arduino Mega 2560 compatible processor, with TICC software loaded.  
> Each system will be tested for function before shipping.
> 
> As I mentioned in my original email, TAPR is going a bit out on a limb to 
> produce the TICC, and we have to make a significant up-front payment to our 
> contract manufacturer. So, early orders are very much appreciated to help 
> recover our cash flow.
> 
> The regular price will be $190 each for the TICC shield with Arduino 
> compatible processor,* but to encourage early orders, we're offering a $10 
> discount for orders placed on or before December 21 -- that makes the price 
> $180 plus shipping.
> 
> You can order from: http://tapr.org/kits_ticc.html
> 
> Thanks!
> John
> 
> * We will provide a Sainsmart version of the Arduino Mega 2560 R3.  They seem 
> to be a reliable supplier and we used these boards for TICC development.
> 
> 
>  Forwarded Message 
> Subject: [time-nuts] New Timestamping / Time Interval Counter: the TICC
> Date: Wed, 23 Nov 2016 10:48:57 -0500
> From: John Ackermann N8UR 
> 
> Counters with resolution below 1 nanosecond are difficult.
> They require either outrageous clock speeds, or interpolators
> that are typically a bunch of analog components mixed with black
> magic and stirred by frequent calibration.  The very best single-shot
> resolution that's been commercially available is 20 picoseconds in
> the Keysight 53230A and HP 5370A/B.  My 5370B has an one-second
> noise ADEV of about 4x10e-11.
> 
> With the help of some very talented friends, I've been working on a new
> counter called the "TICC" with <60ps resolution and similar jitter,
> based on the Texas Instruments TDC7200 time-to-data-converter chip. The
> one-second noise ADEV is about 7x10e-11, not much worse than the 5370,
> but here's the trick:  the TICC is an Arduino shield (mounting on a
> Mega 2560 controller) that weighs only a couple of ounces, requires
> *no* calibration, and is powered from a USB cable!
> 
> The TICC is implemented as a two-channel timestamping counter.  That
> means it can measure one or two low-frequency (e.g., pulse-per-second)
> inputs against an external 10 MHz reference, or it can do a traditional
> time interval measurement of one input against the other.  It can also
> measure period, ratio, or any other function of two-channel  timestamp
> data.  (And by the way -- multiple TICCs can be connected to yield 4,
> 6, 8, or more synchronized channels, though we haven't tested this
> capability yet.)
> 
> I've attached a picture of the TICC prototype as well as an ADEV plot
> of a 17+ day run of multiple measurements taken by two TICCs, and also
> showing the TICC noise floor.  The good news behind that plot is that
> there are more than 6 million data points behind these results, and
> there was not a single glitch or significant outlier among them.
> 
> There's more information available at http://febo.com/pages/TICC
> 
> The software is open source (BSD license) and is available at
> https://github.com/TAPR/TICC -- the current version seems be reliable
> but there are still features to add and a *lot* of cleanup to do; it's
> currently ugly and very much a work in process.
> 
> As always, I'll be making the TICC available through TAPR.  We're still
> finalizing details, but we expect the price to be less than $200 for a
> turn-key system:  TICC mounted on an Arduino with software loaded and
> tested for basic functionality.  We hope to ship the TICC by February.
> 
> I'll post a note in a week or two with final price and ordering
> information.  As a heads up, we will probably offer a small discoun
> for pre-orders.  TAPR is a shoestring non-profit group and the up-front
> cost to manufacture this unit will frankly be a challenge for us.
> Getting pre-orders will help our cash flow significantly, so we ask you
> to keep that in mind.
> 
> John
> 
> 
> 
> 
> 
> 
> 
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Re: [time-nuts] Line Voltage - USA

[Mark Spencer]

Hi David.   I've been told that in Canada the residential supply voltage in a 
neighbourhood is often set to account for the voltage drop in typical 
residential branch circuits. 

The last time the supply voltage in my home was checked it read 125 volts from 
each "service pole" to neutral or 250 volts from service pole to service pole.  
 The voltage on most of my normal branch circuits was typically 122 volts or 
so.   The minor issue for me is that I had a number of dedicated branch 
circuits using larger than normal wire installed that only served one load each 
so the voltage drop on those circuits was negligible.

(I also had the electrical service upgraded which involved larger supply 
conductors to the house which in turn would also have had less voltage drop.)

Good luck.

Mark Spencer



> On Jan 4, 2017, at 5:41 AM, Dr. David Kirkby (Kirkby Microwave Ltd) 
> <drkir...@kirkbymicrowave.co.uk> wrote:
> 
>> On 4 January 2017 at 09:34, Poul-Henning Kamp <p...@phk.freebsd.dk> wrote:
>> 
>> 
>> 
>>> Do you have a reference to this +6%? I've heard from various sources that
>>> the UK is 230 -6%/+10%.  If the EU dictates otherwise, then I'm certainly
>>> over the 6% limit. I may or may not be over the 10% limit.
>> 
>> There was a transitional range, but I belive it has expired.
>> 
>> In 240V countries it was -6%/+10%.
>> 
>> In 220V countries it was -10%/+6%
>> 
>> 
>> --
>> Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
> 
> I measured my voltage overnight in a peak hold at 255.10 V RMS as close to
> the meter as I could. One of the phases goes via a 100 A switch to the
> garage. I measured on the input of that switch. At 230+10% the maximum
> permissible is 253 V, but mine went to 255.10 V. That was measured on a
> Tektronix DMM916 (40,000 counter) meter, which has not been calibrated
> since I bought it new about 20 years ago.
> 
> I spoke to a friend of mine who worked at the CEGB. He thought I might have
> a tough time getting the electricity company to do anything about 2.1 V if
> it was expensive for them to do.
> 
> I was going to report my findings today at
> 
> http://www.ukpowernetworks.co.uk/internet/en/power-cuts/report-it/report-general-issue-form/
> 
> but having spoken to him, I think I'll monitor for a few more nights and
> see if the problem gets worst than 2.1 V outside the specification.
> 
> The specification of the meter is +/- 0.7% + 4 counts, so measuring at 253
> V (maximum permissible mains voltage), the meter specification is +/- 1.81
> V, so there's no doubt that a measurement of 2.10 V above the maximum with
> a meter that's not recently been calibrated, is a bit on the dubious side.
> 
> Perhaps I need something a bit more convincing before reporting this. I was
> thinking of buying a Keysight handheld, but whilst some are cheap, anything
> with a reasonable amount of functionality is quite expensive.
> 
> Dave
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Re: [time-nuts] new year crashes

[Mark Spencer]

In my prior experience (from approx 5 to 20 years ago) actual wide area net 
work links delivered over fiber from commercial providers could have latencies 
of at least several times those figures.   I seem to recall efforts were made 
to lower latencies for applications such as stock trading but I never had any 
exposure to those connections.

Best regards 
Mark Spencer

> 
> How can they get a delay that long?  Satellite link?
> 
> Fiber is 5 microseconds per km.  So 1000 km is 5 ms.
> 
> -- 
> These are my opinions.  I hate spam.
> 
> 
> 
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Re: [time-nuts] new year crashes

[Mark Spencer]

Sorry if this comes across as a bit cynical but...

Presumably system functionality during leap second events would be something 
that is (or could be ?)tested during the pre commissioning phase of a systems 
implementation ?   I would have thought this would be especially important for 
"emergency" systems ?

Are there "leap second" test sets that non time nuts could use to generate leap 
second events during pre commissioning tests ?   (I'm envisioning some form of 
NTP server that could generate leap second events on command ?)

Best regards 
Mark Spencer

Sent from my iPhone

> On Jan 1, 2017, at 2:46 PM, Andy ZL3AG via time-nuts <time-nuts@febo.com> 
> wrote:
> 
> 
> Agreed, but new years eve is a special case for emergency services in 
> particular.
> 
> 
>> On 2/01/2017, at 2:38 AM, Bob Camp wrote:
>> 
>> Hi
>> 
>> Insertion times that are convenient for some could be a major pain for 
>> others. There is no 
>> single “good” time to insert a leap second. You might argue that doing it 
>> while the financial 
>> markets are closed is a good idea. That sort of rules out the middle of the 
>> week. You also
>> could argue that you do it when everybody is on hand to fix things. That 
>> sort of rules out
>> weekends. With two simple “rules”, the entire week has been crossed off the 
>> list ….
>> 
>> If you go back in the archives, you will find significant discussion going 
>> on about dropping
>> leap seconds altogether. That would indeed eliminate the need to schedule 
>> them. It also 
>> would eventually result in some odd adjustments to local time. 
>> 
>> 
>> Bob
>> 
>>> On Jan 1, 2017, at 8:07 AM, Andy ZL3AG via time-nuts <time-nuts@febo.com> 
>>> wrote:
>>> 
>>> 
>>> If so, they should think about adding the leap second on the night of the 
>>> 2nd wednesday of January, or such a time when things are quieter around the 
>>> world.
>>> 
>>> Do they add the leap second at the same moment in time throughout the 
>>> world, or are the clocks here in NZ running 13 hours and 1 second ahead of 
>>> those in the UK for half of Jan 1st?
> 
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Re: [time-nuts] Line Voltage [Was: Anyone (ideally in the UK) ...]

[Mark Spencer]

Hi:

A few quick comments.   

I've used a Variac for years at home to drop the line voltage for older 
equipment with linear power supplies that run hotter than I would like.   (My 
HP5370B's don't fall into that category for me but I can understand why this is 
an issue for some individuals.)

I've encountered situations where the line voltage has been deliberately 
lowered to entire buildings which has in turn caused issues for equipment I was 
responsible for. 

In dealing with line voltage issues in Canada I've found that readings from my 
handheld fluke DMM seem to be accepted at face value by the individuals I've 
been dealing with.   Data collected from UPS systems doesn't seem to be as well 
accepted.

Mark Spencer

> On Jan 1, 2017, at 4:14 AM, Dr. David Kirkby (Kirkby Microwave Ltd) 
> <drkir...@kirkbymicrowave.co.uk> wrote:
> 
>> On 1 Jan 2017 11:10, "Hal Murray" <hmur...@megapathdsl.net> wrote:
>> 
>> The nice thing about the APC units is that they are close to free if you
> are
>> already going to purchase a UPS.
>> 
>> I agree that something like the Dranetz 658 would be better, but a quick
> peek
>> at eBay shows prices far beyond what I'm willing to pay.
>> 
>>> What's the sample rate on your APC UPS?
>> 
>> I don't know what the internal sampling rate is.  The API is
>>  tell me the current voltage
>>  tell me the lowest voltage since the last time I asked
>>  tell me the highest voltage since the last time I asked
> 
> Em, not a lot. My handheld true RMS Tektronix can give me the average. (One
> assumes an average of RMS values).
> 
>> I have a hack that reads as fast as it can.  If nothing interesting has
>> happened, it adds a line to the log file every 5 minutes.
> 
> Again,  I think if attending presenting data for others,  one wants to
> avoid hacks like that. One can always post-proces to indicate the points of
> particular interest.
> My biggest problem is that it is not very practical to log data at the
> incoming point, which is just above my back door.  If I lived on my own,  I
> could set up equipment easily to do this. But sharing a house with a my
> wife and a large German Shepherd dog, it is not practical to do it with the
> equipment I have.
> 
> I think measuring voltage elsewhere would give someone more reason to
> question its accuracy.  In my case, measuring in my lab would almost
> certainly give a power supply voltage lower than that coming in.
> 
> Anyway,  short term I will use a variac to lower the voltage to test
> equipment with linear power supplies.  I am less concerned about equipment
> with switch mode supplies.
> 
> Dave.
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Re: [time-nuts] How phase stable is rg59 or alternate coax

[Mark Spencer]

At one point I contemplated running Andrews "Heliax" for my GPS antenna.   Part 
of the rationale was due to the data presented in page 2 of the following paper.

http://ivs.nict.go.jp/mirror/meetings/v2c_wm1/phase_stability.pdf

I subsequently decided to stay with my existing run of plenum rated RG58.  The 
bulk of my cable run is indoors where the temperature is fairly stable.

Regards
Mark Spencer



> On Nov 21, 2016, at 12:59 PM, Scott Stobbe <scott.j.sto...@gmail.com> wrote:
> 
> When I first took a look at some of the coax datasheets I couldn't find
> anything. I was able to find the following paper "phase stability of
> typical navy radio frequency coaxial cables"
> http://www.dtic.mil/dtic/tr/fulltext/u2/628682.pdf I attached the table
> from the last page. They estimate RG59 to have a tempCo of -330 PPM/degC
> for electrical length. They also estimated RG-58 at -480 PPM/degC.
> 
>> On Mon, Nov 21, 2016 at 2:44 PM, John Ackermann N8UR <j...@febo.com> wrote:
>> 
>> I can't find the data right now, but will keep digging.  There's also a
>> short paper from the early 2000s from Haystack on their measurement of
>> LMR400 in an environmental chamber.  They came to the same conclusion, but
>> I can't find that paper either. :-
> 
> 
> John, many thanks for the Haystack tip! That is a wonderful paper, I
> believe the one you are quoting is "Dispersion and temperature effects in
> coax cables" http://www.haystack.mit.edu/tech/vlbi/mark5/mark5_memos/067.pdf
> 
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Re: [time-nuts] Thinking outside the box a super reference

[Mark Spencer]

On a somewhat related note

Several years ago I pondering getting a Cs standard.   After considering the 
performance of my references and my stack of time interval counters I concluded 
that in practice I could more or less get the level of measurement accuracy I 
wanted by comparing the "device under test" to a reference and at the same time 
comparing the reference to several other references.   I wouldn't want to use 
this technique in a professional setting but for my hobby use I believe it met 
my needs.

In hindsight though I expect I could have bought a fairly nice Cs unit for the 
money I sunk into the time interval counters and the various references but 
that wouldn't have been as much fun.  The wear out aspects of used Cs standards 
are also a bit of a concern for me.   That being said a few of my time interval 
counters have also stopped working properly so I seem to have just traded one 
set of issues for another but I'm considerably more optimistic of being able to 
repair / re align a couple of my HP5370's than trying to revive a dead Cs 
standard.

All the best 
Mark S



> On Nov 3, 2016, at 1:37 PM, Ruslan Nabioullin  wrote:
> 
>> On 11/03/2016 04:07 PM, Bert Kehren via time-nuts wrote:
>> 
>> Over the past there has been talk about building from  scratch high
>> performance references. I think consensus was that it is out of  reach.
> 
> What about instead establishing an open-source hardware project for a 
> frequency standard fusor?  I was researching COTS solutions for this for my 
> rubidium ensemble and could only find this one product, which obviously 
> should be exorbitant in cost: 
> http://vremya-ch.com/english/product/indexe817.html?Razdel=11=54
> 
> -Ruslan
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Re: [time-nuts] Temp/Humidity control systems?

[Mark Spencer]

Hi John.   You might want to look at "precision air conditioning" systems (to 
use the vendors phraseology) designed for small computer rooms for some ideas ?

I suspect getting close to your temperature spec may be easier than your 
humidity spec ?   There may also be issues getting commercial units permitted / 
installed / inspected in a residential setting ?

As a side note I was impressed with the split unit my residential HVAC 
contractor installed during a recent Reno in my TV room.  The newer units seem 
to have finer temperature units than the older ones.  I don't believe my unit 
features any humidity control.


Hope this is of some interest.

Mark Spencer

> On Oct 26, 2016, at 10:58 AM, John Ackermann N8UR <j...@febo.com> wrote:
> 
>> On 10/26/2016 1:00 PM, Richard (Rick) Karlquist wrote:
>>> On 10/26/2016 8:59 AM, John Ackermann N8UR wrote:
>>> I may have the opportunity to build a small "clock room" and am
>>> considering whether I could make it an environmentally controlled space.
>>> I'd like to learn about the options for doing this.
>>> 
>>> The space would probably be 6x8 feet or so, in a basement with one
>>> outside wall.
>> 
>> I'm lost with the basic concept here.  Help me understand this.
> 
> This room would be a large closet in my basement where two racks of various 
> OCXO, Rb, Cs live. There wouldn't be a lot of in-and-out traffic. I'm not 
> looking for 0.01 degree regulation -- <1 degree C and a few percent humidity 
> throughout the year seems a reasonable goal.
> 
> What I envisioned was a very small heat pump or other heating/air-con unit 
> coupled with some sort of proportional control. I just don't know where to 
> start looking for that, or what other issues to be thinking about.
> 
> (I know the way time-nuts think, and I recall the great ideas posted here in 
> the past about using an old refrigerator, or burying standards in a deep hole 
> -- but this would be wrapped into a bigger construction project that I'm 
> going to be managing from a distance, so I need to keep it fairly 
> straight-forward.)
> 
> Thanks, all!
> 
> John
> 
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Re: [time-nuts] HP 59309A Clock runs, sets via GPIB, but no GPIB output?

[Mark Spencer]

Hi in the (probably unlikely) event another tester would help I have a 59309a 
and a spare prologix gpib / Ethernet adaptor.   

I may try this code out at some point in any event.

Best regards
Mark S


Sent from my iPhone

> On Oct 7, 2016, at 5:15 PM, Tom Van Baak  wrote:
> 
> Hi Bob,
> 
> Yes, the hp 59309A is a wonderful little LED clock. I just re-tested the 
> program I wrote to read/write the time and it still works.
> 
> For others that are wondering, the code is at 
> http://leapsecond.com/tools/hp59309.c and a Win32 exe is there too.
> 
> Anyway, one possible suggestion is for you to use ++read 10 instead of just 
> ++read. The 59309A is an early byte-oriented HP-IB device and the Prologix 
> command set is more meant for line oriented communication (using CR or LF or 
> EOI for termination). So when I use ++read10 everything is fine, but ++read, 
> or ++read9 or ++read11 or ++read anything else will cause the Prologix to go 
> into an infinite loop.
> 
> One other idea that may shed light on your problem is to use the /d (debug) 
> option and have a look at the exact communication between the program and the 
> Prologix and the 59309A. Then do the same with your Python code to see if it 
> matches, down to the byte. Again, these vintage HP-IB instruments are 
> wonderfully simple but they don't always take well to things we take for 
> granted these days like extraneous line terminators or spaces or open-ended 
> reads and such. If you really want some fun, use a GPIB bus analyzer.
> 
> Attached is the debug log from my 59309A.
> 
> If all else fails I can send you a known working 59309A so you can tell if 
> the problem is with your PC, your Python tool, your Prologix, or your 59309A.
> 
> /tvb
> 
> - Original Message - 
> From: "Bob" 
> To: "TimeNuts" 
> Sent: Thursday, October 06, 2016 12:56 PM
> Subject: [time-nuts] HP 59309A Clock runs, sets via GPIB, but no GPIB output?
> 
> 
> I'd like to ask the HP 59309A owners on time-nuts if the following symptoms 
> sound familiar, and if so, what would the fix be?
> 
> o New-to-me HP 59309A clock.
> o Late build, 1985 date code on many parts.
> o I replaced the big 1900 uF electrolytic before plugging it in.
> o Visual inspection very clean, no corrosion, no battery.
> o 12v reads 13.1v, 5v reads 5.3v, -2v reads -2.9v.
> o Front panel switches and buttons all work as expected.
> o Internal and external osc. both work as expected.
> o Internal "format" switch set to  i.e. comma, cal, no space.
> o GPIB works to *set* the time, using Prologix Ethernet adapter.
> o Prologix Ethernet adapter attached directly to the clock, no cables.
> o Python code to set via GPIB attached below.
> o Setting time via GPIB always works, tried many times.
> o Reading time has never worked.  All I get is lots of ASCII 
> 444...
> o Reading with Prologix ++read command
> o Switches set to 1100010 i.e. Listen, ADDR 2 for normal operation
> o Tried switches as 010 i.e. Talk Only, also resulted in continuous 
> 444...
> o Tried very long delays between every GPIB command, no change.
> o Tried removing top cover and running a fan to bring entire clock to 21C, no 
> change.
> o Tried gently reseating the four boards and three socketed PROMS, no change.
> 
> Thanks to TVB for hp59309.c sample Windows Prologix USB code.  I based the 
> Python Ethernet code on TVB, to read from the clock he sends command C and 
> then ++read.  When I do that all I get are a zillion 0x34 '4' characters.
> 
> Seems strange that all the GPIB commands work.  I tried R reset, P pause T 
> resume D day H hour M minute S second manually and they all work just fine.  
> I have never been able to read anything reasonable though.
> 
> As to the Prologix Ethernet adapter, I believe it is working OK electrically 
> as I have been using it for weeks at a time reading PPS time intervals from a 
> trusty HP 5334B counter, the adapter has read hundreds of thousands times 
> from the 5334B.
> 
> Is there a trick to using the Prologix to read from the 59309A?
> 
> I did notice that the 59309A has at least one trick - in TVB's code where he 
> reads the Prologix settings and only writes them if they need to be changed, 
> that is actually required(!).  Just writing them every time seems to put the 
> adapter into a strange state.
> 
> Page 4-2 of the 59309A manual seems to imply that the "Output State Machine" 
> generates the GPIB output messages, using input from the "Data Memory".  
> AFAICT, those two functional blocks are the only ones that are not working 
> for me.
> 
> I think A4U18 ROM is OK as it handles GPIB command decoding and R P T D H M S 
> commands all work.
> 
> A5U15 appears to do the ASCII encoding for SP, CR, LF, ", : so it may or may 
> not be OK.
> 
> A5U2 is described as "STATE MACHINE ROM (A5U2). This 4K ROM controls the 
> operation of the circuits that develop the talk output 

Re: [time-nuts] Need Time Help

[Mark Spencer]

In practice I'm not convinced the timing requirements for the JT modes in 
question are even more than a single order of magnitude more severe than the 
when I have been timing 15 second sequences on my wrist watch during manual non 
computer aided weak signal operations.  To recap if some one has data or direct 
personal experience to make the case that extreme levels of timing accuracy 
will help I'd be interested in seeing this.

That being said I do believe it makes sense to fully use what ever timing 
resources one has access to.

All the best
Mark S

Sent from my iPhone

> On Oct 5, 2016, at 9:47 AM, Wes  wrote:
> 
> If you are working "real" EME where you, and not a computer plus lookup 
> table, are coping the signals, none of these precise timing issues exist.
> 
> Wes  N7WS
> 
>> On 10/5/2016 6:18 AM, Peter Torry via time-nuts wrote:
>> I must admit to being rather puzzled at the sub microsecond timing 
>> requirement as I use ntp to set the W7 clock in my computer and have not had 
>> any issues. In fact less than one second is OK for the usual two minute 
>> periods that are required to allow for the Faraday rotation. Although I use 
>> a GPSDO for a frequency reference I find JT software reasonably tolerant of 
>> frequency.  As I may be missing something I would welcome observations on 
>> how important the period timing requirement is, you never know I might get 
>> more contacts.
>> 
>> Regards
>> 
>> Peter
>> 
>> 
>>> On 05/10/2016 12:50, Graham / KE9H wrote:
>>> For the group. This ham is trying to work EME. Earth-Moon-Earth propagation
>>> path. Aka, "moonbounce."
>>> 
>>> He is trying to time synchronize a system, where the other station he is
>>> communicating
>>> with can be any other place on the Earth that can also see the Moon.
>>> 
>>> So the system time sync is for a little bit tougher case than a local area
>>> network.
>>> 
>>> --- Graham
> 
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Re: [time-nuts] Need Time Help

[Mark Spencer]

Yes I'd be curious in knowing more about this as well.  I've often observed 
time differences from other stations of several tenths of a second when running 
the JT modes on HF.  Although I am beginner at EME I have made a couple of EME 
(earth moon earth) JT65 contacts on VHF without taking any special measures to 
sync the time on a Windows XP machine beyond using the built in features of the 
operating system to sync to my own local time server which was in turned synced 
to the 1 pps output of a GPS timing receiver.

I've also made FSK441 contacts (another related form of amateur radio digital 
communications) in the field without any time reference besides the free 
running clock in my Windows xp laptop.  If there is a significant performance 
improvement to be had with these modes by having time nuts levels of timing 
precision on my computers I'd be very interested to know more.  

All the best 
Mark S

Sent from my iPhone

> On Oct 5, 2016, at 6:18 AM, Peter Torry via time-nuts  
> wrote:
> 
> I must admit to being rather puzzled at the sub microsecond timing 
> requirement as I use ntp to set the W7 clock in my computer and have not had 
> any issues. In fact less than one second is OK for the usual two minute 
> periods that are required to allow for the Faraday rotation. Although I use a 
> GPSDO for a frequency reference I find JT software reasonably tolerant of 
> frequency.  As I may be missing something I would welcome observations on how 
> important the period timing requirement is, you never know I might get more 
> contacts.
> 
> Regards
> 
> Peter
> 
> 
>> On 05/10/2016 12:50, Graham / KE9H wrote:
>> For the group. This ham is trying to work EME. Earth-Moon-Earth propagation
>> path. Aka, "moonbounce."
>> 
>> He is trying to time synchronize a system, where the other station he is
>> communicating
>> with can be any other place on the Earth that can also see the Moon.
>> 
>> So the system time sync is for a little bit tougher case than a local area
>> network.
>> 
>> --- Graham
> 
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Re: [time-nuts] A new take on the all-hardware GPSDO concept

[Mark Spencer]

Hi Lars.   I own a G3RUH (Miller) GPSDO.

>From what I can recall  While testing mine with  my collection of 
>HP5370B's and my assortment of references the performance of mine while locked 
>was generally comparable to the one in the link you provided.   I never tested 
>it "un locked."  

I couldn't measure phase noise and the performance of my test setup at taus of 
less than 100 seconds or so was probably a limitation as well.   My references 
(BVA OCXO, PRS10 rb and a cherry picked Z3805 GPSDO) probably weren't really 
good enough either.

It is a nice unit that I have currently loaned out to a local amateur radio 
operator.   Acquiring it lead to me spending a sizeable amount of time and 
money on time nuts pursuits over the years.

Sent from my iPhone

> On Sep 16, 2016, at 1:13 PM, Lars Walenius  wrote:
> 
> Hi Nick,
> 
> Jim Millers design is very clever and as I see can give results as good as a 
> digital approach but it has the same limitations:
> The GPS jitter and the oscillator jitter in combination with the loop 
> bandwidth.
> 
> The only ADEV I have seen for the Miller GPSDO is this one  
> http://www.leapsecond.com/pages/gpsdo/  .
> Can anyone point me to other tests?
> 
> The ADEV I see on leapsecond.com indicates for me a time constant of around 
> 200seconds. That is what you get with a OCXO range of 0.25ppm. You don´t need 
> to have a large RC-filter. The original R1-C1 time constant with 16 seconds 
> time constant will work as long as the internal oscillator in the Jupiter-T 
> is at least some Hz away from a multiple of 10kHz. If that is true the 
> sawtooth out of the Jupiter will have enough high frequency to be easily 
> filtered by the RC. This is of course a risk. See for example: 
> https://www.febo.com/pipermail/time-nuts/2005-August/019106.html . If you get 
> a hanging bridge you have at least as much trouble as a non sawtooth 
> corrected GPSDO and probably much worse as the RC filter is only 16s. In the 
> digital approach the prefilter may filter away the hanging bridge (in best 
> case).
> 
> As I understand the Miller GPSDO with a OCXO with a 0.25ppm range and 10kHz 
> into an XOR phase detector and 16s RC will be very similar to a digital 
> approach with a TIC (Time interval counter ) with +-25us range followed by a 
> prefilter with time constant 16s and a loop with just the P-term with a time 
> constant of 200secs. As it has no I-term it will have slightly less noise but 
> the output phase will drift as soon as the OCXO drifts (as a FLL). The 
> resolution of the XOR phase detector (TIC) will be limited by the noise but 
> as 0.1mV is 1ns the resolution can be seen as better than 1ns is my 
> conclusion. A problem might be that the output of the XOR drifts with the 5V 
> supply but this can be seen as the same problem as the DAC drift in a digital 
> approach.
> 
> My conclusion (without testing) is that the Jupiter-T 10kHz is very good but 
> not better than the sawtooth corrected outputs from M12 or LEA6T receivers. 
> That is the ADEV can be approximated by 1E-9/Tau (1E-12 at 1000s) in good 
> conditions.
> 
> My experience with the Venus838-T is only 2 weeks but disappointing. This can 
> also be guessed from the datasheet ADEV curve, that I guess is sawtooth 
> corrected values as it starts at 3E-9 at 1s, but is only 1E-11 at 1000s a 
> factor 10 worse than I get with the LEA-6T with the same antenna and setup. 
> If anyone have ADEV-MDEV curves to share I would be glad to see what can be 
> achieved with the venus838-T. My conclusion is also that sawtooth correction 
> is useless on my 838-T.
> 
> Lars
> 
> 
>> Nick wrote:
> 
>> Jim Miller's 10 kHz GPSDO that’s been referenced here has either solved this 
>> problem, or the 10 kHz output of the >Jupiter is substantially better than 
>> the Venus’ 10 MHz output, or the design doesn’t give the results time-nuts 
>> expect >from a GPSDO. Which of those applies?
> 
> 
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Re: [time-nuts] HP-105B Battery Replacement?

[Mark Spencer]

In my experience the commonly seen UPS's that support external batteries expect 
you to use the batteries supplied (or at least specified) by the manufacturer.  
  

That being said I have come across UPS systems that are designed to work with 
generic user supplied 12 volt batteries but in my experience they are much less 
common.  Some of them even have adjustments to provide different charging 
voltages for different types of batteries.

Sorry this is getting a bit off topic.

All the best
Mark S



Sent from my iPhone

> On Sep 15, 2016, at 4:06 PM, Bob kb8tq  wrote:
> 
> Hi
> 
> They are very common when you look at server UPS or larger units. There are 
> literally hundreds of models to pick between. Prices are from roughly $400 up 
> to a few hundred thousand dollars per unit.
> 
> Bob
> 
>> On Sep 15, 2016, at 6:13 PM, Jeremy Nichols  wrote:
>> 
>> Since I have a 12V 100 A-H gelled electrolyte battery as a
>> short-term backup (for those outages not worth firing up the generator),
>> I'd like to find a UPS that uses an external battery. So far I don't see
>> such a thing--do they exist?
>> 
>> Jeremy
>> 
>>> On Thursday, September 15, 2016, Bob Camp  wrote:
>>> 
>>> Hi
>>> 
>>> It’s been quite a while since I bought anything other than a pure sine
>>> UPS. They really aren’t as expensive
>>> as they once were. You may find them a bit cheaper from outfits like
>>> CyberPower than from APC. Sometimes
>>> it s a bit tough to work out exactly what is or is not a pure sine wave
>>> unit. If you want a full “always on” pure
>>> sine device, they are still a bit expensive.
>>> 
>>> Bob
>>> 
> On Sep 15, 2016, at 2:13 PM, Jeremy Nichols > wrote:
 
 Your point is well made. My question is: what happens to the quality of
>>> the output sine wave if I use anything other than a true sine-wave (i.e.,
>>> expensive) UPS? Most of them these days produce a semi-sine wave (aka
>>> modified square wave) that may or may not play well with the 105B. Anyone
>>> have experience?
 
 A external battery and appropriate chargers and cabling does sound like
>>> another good alternative. Harder to move around but I don't (yet) have such
>>> a need, only that the 105B stay "on" regardless of power failures.
 
 Jeremy
 
 
> On 9/15/2016 10:15 AM, Bob Camp wrote:
> Hi
> 
> A bigger question becomes:
> 
> Do batteries inside equipment make much sense anymore?
> 
> These days, a UPS is often a standard part of a rack in an outage prone
>>> area. Powering
> the “whatever” instrument off of the same UPS as the rest of the stuff
>>> is one obvious
> answer.
> 
> The other answer is an even older approach. Use a battery bank that is
>>> external to all
> the gear in the rack and tend it independently of each box in the rack.
>>> That way you have
> a few very large cells to worry about rather than a whole bunch
>>> scattered about. Things like
> lead acid that are impractical in a piece of gear are more of an option
>>> in an independent
> battery box. A single charger / line supply makes it easier to invest
>>> in something with real
> smarts in it. The advent of dirt cheap isolated switchers makes the
>>> conversion to instrument
> voltages a lot easier than it once was. Pick a common voltage like 12,
>>> 24, or 48V and run with it.
> 
> My answer to the frequency standard battery pack question has become
>>> “don’t do it”. It makes
> them a *lot* lighter weight !!!
> 
> Bob
 
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 time-nuts mailing list -- time-nuts@febo.com 
 To unsubscribe, go to https://www.febo.com/cgi-bin/
>>> mailman/listinfo/time-nuts
 and follow the instructions there.
>>> 
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>>> and follow the instructions there.
>> 
>> 
>> -- 
>> Sent from Gmail Mobile
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Re: [time-nuts] HP-105B Battery Replacement?

[Mark Spencer]

Thanks I was  aware of Ni Fe batteries but have never seen them for sale at the 
local "battery store" where I buy batteries for my vehicles, time nuts and 
amateur radio pursuits (:

I view lead acid batteries (especially ones designed for in door use) as semi 
expendable for my various hobbies.I figure I got my monies worth from the 
ones backing up the HP105B and FTS 1050 as I am well on my way to 10 years of 
up time for those two devices. 

I tend to replace  batteries on general principles every 5 years or so or at 
least move them to a less demanding application.   (Ie. shuffle them from time 
nuts backup use to portable power use for amateur radio.)

Sent from my iPhone

> On Sep 15, 2016, at 3:13 PM, Alexander Pummer <alex...@ieee.org> wrote:
> 
> if you deep discharge led acid batteries -- which are not made special for 
> deep discharge -- you will have to replace them quite often, on the other 
> hand Ni-Fe batteries you could short out, overcharge they are undisrtuktable 
> that is the reason why they are not produced any more in the US, they do not 
> fit into the American business-model, but phone companies, railway and 
> aviation still using them, you could still find old electrical forklifts with 
> Ni-Fe battery made by Edison Batteries in the sixties in the past century the 
> batteries are still fine. Tudor -- a led-acid battery producer -- purchased 
> Edison Batteries and closed down the formidable competitor
> 
> 73
> KL6UHN
> Alex
> 
>> On 9/15/2016 2:26 PM, Mark Spencer wrote:
>> Hi I've run my HP105B (with the old style oscillator) from AC power via a 
>> consumer grade UPS, 24 Vdc from a lead acid battery bank and briefly from 
>> the internal battery pack with out any notable changes in performance (that 
>> being said I can't measure phase noise so this observation may or may not be 
>> of use.)
>> 
>> I'm not to fussed over the internal Nicad pack and rely on an external 
>> battery bank in case I loose AC power for an extended time period.
>> 
>> During a two day outage my HP105B and FTS1050 ran nicely from a 100 AH 
>> battery bank but the batteries needed to be replaced shortly afterwards.
>> 
>> Sent from my iPhone
>> 
>>> On Sep 15, 2016, at 11:13 AM, Jeremy Nichols <jn6...@gmail.com> wrote:
>>> 
>>> Your point is well made. My question is: what happens to the quality of the 
>>> output sine wave if I use anything other than a true sine-wave (i.e., 
>>> expensive) UPS? Most of them these days produce a semi-sine wave (aka 
>>> modified square wave) that may or may not play well with the 105B. Anyone 
>>> have experience?
>>> 
>>> A external battery and appropriate chargers and cabling does sound like 
>>> another good alternative. Harder to move around but I don't (yet) have such 
>>> a need, only that the 105B stay "on" regardless of power failures.
>>> 
>>> Jeremy
>>> 
>>> 
>>>> On 9/15/2016 10:15 AM, Bob Camp wrote:
>>>> Hi
>>>> 
>>>> A bigger question becomes:
>>>> 
>>>> Do batteries inside equipment make much sense anymore?
>>>> 
>>>> These days, a UPS is often a standard part of a rack in an outage prone 
>>>> area. Powering
>>>> the “whatever” instrument off of the same UPS as the rest of the stuff is 
>>>> one obvious
>>>> answer.
>>>> 
>>>> The other answer is an even older approach. Use a battery bank that is 
>>>> external to all
>>>> the gear in the rack and tend it independently of each box in the rack. 
>>>> That way you have
>>>> a few very large cells to worry about rather than a whole bunch scattered 
>>>> about. Things like
>>>> lead acid that are impractical in a piece of gear are more of an option in 
>>>> an independent
>>>> battery box. A single charger / line supply makes it easier to invest in 
>>>> something with real
>>>> smarts in it. The advent of dirt cheap isolated switchers makes the 
>>>> conversion to instrument
>>>> voltages a lot easier than it once was. Pick a common voltage like 12, 24, 
>>>> or 48V and run with it.
>>>> 
>>>> My answer to the frequency standard battery pack question has become 
>>>> “don’t do it”. It makes
>>>> them a *lot* lighter weight !!!
>>>> 
>>>> Bob
>>> ___
>>> time-nuts mailing list -- time-nuts@febo.

Re: [time-nuts] HP-105B Battery Replacement?

[Mark Spencer]

They do exist.   I've seen them in service at Telecom sites outside of the U.S. 
and Canada.   I believe there was a thread re this a few years ago ?

Sent from my iPhone

> On Sep 15, 2016, at 3:13 PM, Jeremy Nichols  wrote:
> 
> Since I have a 12V 100 A-H gelled electrolyte battery as a
> short-term backup (for those outages not worth firing up the generator),
> I'd like to find a UPS that uses an external battery. So far I don't see
> such a thing--do they exist?
> 
> Jeremy
> 
>> On Thursday, September 15, 2016, Bob Camp  wrote:
>> 
>> Hi
>> 
>> It’s been quite a while since I bought anything other than a pure sine
>> UPS. They really aren’t as expensive
>> as they once were. You may find them a bit cheaper from outfits like
>> CyberPower than from APC. Sometimes
>> it s a bit tough to work out exactly what is or is not a pure sine wave
>> unit. If you want a full “always on” pure
>> sine device, they are still a bit expensive.
>> 
>> Bob
>> 
 On Sep 15, 2016, at 2:13 PM, Jeremy Nichols >> > wrote:
>>> 
>>> Your point is well made. My question is: what happens to the quality of
>> the output sine wave if I use anything other than a true sine-wave (i.e.,
>> expensive) UPS? Most of them these days produce a semi-sine wave (aka
>> modified square wave) that may or may not play well with the 105B. Anyone
>> have experience?
>>> 
>>> A external battery and appropriate chargers and cabling does sound like
>> another good alternative. Harder to move around but I don't (yet) have such
>> a need, only that the 105B stay "on" regardless of power failures.
>>> 
>>> Jeremy
>>> 
>>> 
 On 9/15/2016 10:15 AM, Bob Camp wrote:
 Hi
 
 A bigger question becomes:
 
 Do batteries inside equipment make much sense anymore?
 
 These days, a UPS is often a standard part of a rack in an outage prone
>> area. Powering
 the “whatever” instrument off of the same UPS as the rest of the stuff
>> is one obvious
 answer.
 
 The other answer is an even older approach. Use a battery bank that is
>> external to all
 the gear in the rack and tend it independently of each box in the rack.
>> That way you have
 a few very large cells to worry about rather than a whole bunch
>> scattered about. Things like
 lead acid that are impractical in a piece of gear are more of an option
>> in an independent
 battery box. A single charger / line supply makes it easier to invest
>> in something with real
 smarts in it. The advent of dirt cheap isolated switchers makes the
>> conversion to instrument
 voltages a lot easier than it once was. Pick a common voltage like 12,
>> 24, or 48V and run with it.
 
 My answer to the frequency standard battery pack question has become
>> “don’t do it”. It makes
 them a *lot* lighter weight !!!
 
 Bob
>>> 
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>>> time-nuts mailing list -- time-nuts@febo.com 
>>> To unsubscribe, go to https://www.febo.com/cgi-bin/
>> mailman/listinfo/time-nuts
>>> and follow the instructions there.
>> 
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>> mailman/listinfo/time-nuts
>> and follow the instructions there.
> 
> 
> -- 
> Sent from Gmail Mobile
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Re: [time-nuts] HP-105B Battery Replacement?

[Mark Spencer]

Hi I've run my HP105B (with the old style oscillator) from AC power via a 
consumer grade UPS, 24 Vdc from a lead acid battery bank and briefly from the 
internal battery pack with out any notable changes in performance (that being 
said I can't measure phase noise so this observation may or may not be of use.)

I'm not to fussed over the internal Nicad pack and rely on an external battery 
bank in case I loose AC power for an extended time period.   

During a two day outage my HP105B and FTS1050 ran nicely from a 100 AH battery 
bank but the batteries needed to be replaced shortly afterwards.

Sent from my iPhone

> On Sep 15, 2016, at 11:13 AM, Jeremy Nichols  wrote:
> 
> Your point is well made. My question is: what happens to the quality of the 
> output sine wave if I use anything other than a true sine-wave (i.e., 
> expensive) UPS? Most of them these days produce a semi-sine wave (aka 
> modified square wave) that may or may not play well with the 105B. Anyone 
> have experience?
> 
> A external battery and appropriate chargers and cabling does sound like 
> another good alternative. Harder to move around but I don't (yet) have such a 
> need, only that the 105B stay "on" regardless of power failures.
> 
> Jeremy
> 
> 
>> On 9/15/2016 10:15 AM, Bob Camp wrote:
>> Hi
>> 
>> A bigger question becomes:
>> 
>> Do batteries inside equipment make much sense anymore?
>> 
>> These days, a UPS is often a standard part of a rack in an outage prone 
>> area. Powering
>> the “whatever” instrument off of the same UPS as the rest of the stuff is 
>> one obvious
>> answer.
>> 
>> The other answer is an even older approach. Use a battery bank that is 
>> external to all
>> the gear in the rack and tend it independently of each box in the rack. That 
>> way you have
>> a few very large cells to worry about rather than a whole bunch scattered 
>> about. Things like
>> lead acid that are impractical in a piece of gear are more of an option in 
>> an independent
>> battery box. A single charger / line supply makes it easier to invest in 
>> something with real
>> smarts in it. The advent of dirt cheap isolated switchers makes the 
>> conversion to instrument
>> voltages a lot easier than it once was. Pick a common voltage like 12, 24, 
>> or 48V and run with it.
>> 
>> My answer to the frequency standard battery pack question has become “don’t 
>> do it”. It makes
>> them a *lot* lighter weight !!!
>> 
>> Bob
> 
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Re: [time-nuts] The home time-lab

[Mark Spencer]

I also have had good results with various APC UPS systems.   

I typically have to replace the batteries in my UPS's and my stand alone backup 
batteries every 5 to 7 years or so.   Units such as the HP105B and FTS1050 that 
feature backup DC power inputs simplify the provision of long term backup power 
in my experience.   

Last summer we had a two day power outage when I was away (so my generator 
sitting in the garage was of no use.)  My 100 amp hour battery system kept my 
HP105B and FTS1050 running while everything else lost power.  On occasion I've 
run my BVA from the battery system as well.   Using my HP5370's I've never been 
able to detect a difference in performance of my OCXO's running on battery 
power vs AC line power (or DC supplied from an HP linear supply in the case of 
the BVA.)

All the best
Mark Spencer

Sent from my iPhone

> On Jul 8, 2016, at 8:23 AM, Charles Steinmetz <csteinm...@yandex.com> wrote:
> 
> David wrote:
> 
>> This is the only deal I see at the moment but I do
>> not know how suitable it would be and it is more
>> than I paid although about twice as powerful:
>> 
>> http://www.upsforless.com/apcsurta1500xlref.aspx
> 
> I have a fleet of its bigger brothers, the 2000XL and 2200XL, and recommend 
> them highly.  The conversion engines are rated for continuous duty, so you 
> can add as many extra battery packs as you like to extend the run time (most 
> UPSs designed for home use -- even very expensive ones -- do not have enough 
> cooling to run continuously, so they depend on the battery going dead to keep 
> them from burning down).
> 
> That price is not bad, IMO, if they come with fresh, GOOD QUALITY batteries. 
> I strongly advise NOT using the generic black Chinese batteries -- IME, they 
> are worthless crap. If you live somewhere you can get genuine Panasonic SLA 
> batteries, use those [but BEWARE of fakes!!]. Here in the US, the PowerSonic 
> SLAs are the best I've found.  I get mine from "ecomelectronics" on ebay [no 
> affiliation, just a satisfied customer].
> 
> I have had no RF interference issues, or any other problems other than bad, 
> generic black Chinese batteries.  The APC supplies are rugged and 
> well-protected -- one battery pack I hadn't rebuilt (full of the generic 
> black batteries) failed in a spectacular fashion (sparks and smoke and melted 
> plastic *from the batteries*).  The UPS itself suffered no damage.
> 
> Best regards,
> 
> Charles
> 
> 
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Re: [time-nuts] HF frequency counting receiver

[Mark Spencer]

To echo the point that Jim Lux made in another post...

I'm not sure how those of us who live an appreciable distance from the 
transmitters can expect to get mili hertz accuracy  in light of the HF Doppler 
shift over long distance paths with restorting to tactics such as 
simultaneously monitoring another transmitter that has a precisely known 
frequency and is located near the target transmitter to determine what the 
Doppler shift is at a given point of time.   (I'm not 100 percent sure this 
approach would work but it seems viable to me at first glance.)

I've spent some quality time monitoring WWV, and have read various papers and I 
am quite convinced that HF Doppler shift is a real issue at times.


All the best
Mark S
VE7AFZ

Sent from my iPhone

> On Jun 20, 2016, at 10:10 AM, Graham / KE9H  wrote:
> 
> You need to be able to measure frequency accurately in the milli-Hertz
> range to be competitive in the frequency measuring contests.
> 
> I doubt the Selective Voltmeters have that level of resolution. I think
> they 'only' read to 0.1 Hz.
> 
> --- Graham
> 
> 
> 
> On Mon, Jun 20, 2016 at 11:52 AM, Pete Lancashire 
> wrote:
> 
>> Never tried it but a Selective Level Meter aka HP 3586A/B/C ?
>> 
>> On Mon, Jun 20, 2016 at 7:51 AM, Nick Sayer via time-nuts
>>  wrote:
>>> I'm considering taking a shot at the next ARRL frequency measurement
>> contest.
>>> 
>>> The assumption going in is that the signal is CW, with at least a half
>> minute or so of just solid "on" at one point or another and that reception
>> is reasonably good.
>>> 
>>> I've got a good TIA and excellent references, but that's the easy part,
>> it seems to me. It seems to me that what I really need to do is make a
>> synthesized heterodyne receiver that can present an accurately tuned RF
>> band pass - say, 10 kHz wide with the synthesizer set for
>>> 5 kHz steps - to the TIA, with some manually tunable high-pass and
>> low-pass filtering to isolate the signal of interest. If the mixer got its
>> LO from a synthesizer with a GPSDO reference, it seems to me that you could
>> then measure the frequency of the signal of interest (now an audio
>> frequency, so you can listen to it too) with the TIA (also getting the
>> GPSDO reference) and then do simple math to arrive at the actual RF
>> frequency.
>>> 
>>> Anybody have any thoughts?
>>> 
>>> 
>>> Sent from my iPhone
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Re: [time-nuts] RG6 or LMR400 for GPS Antenna (Symmetricom 58532A and T-bolt)

[Mark Spencer]

That is more or less the same method I use for my amateur radio activities.   
Home Depot in Canada sells similar 3M products which is helpful during quick 
weekend projects.

Professionally I've seen other methods used but on my own time I like the 
"splicing tape" covered with super "33 tape" approach.  

These days I mostly use "N" connectors which in my experience can be a bit more 
forgiving of less than perfect weather proofing than certain other types.   
(Not all "N" type connectors are equal in my view.)

Your experience and results may differ from mine.

73
Mark S
VE7AFZ

Sent from my iPhone

> On Apr 21, 2016, at 1:12 PM, DaveH  wrote:
> 
> DX Engineering (another great compuany to do business with) recomends these
> two products:
> 
> http://www.dxengineering.com/
> 
> 
> 3M Temflex 2155 Rubber Splicing Tape followed with a covering of
> Scotch Super 33+ tape
> 
> The rubber conforms tightly with the connectors and waterproofs the
> connection while the Super 33+ tape seals everything up and protects the
> joint from UV degredation and mechanical abrasion.
> 
> There is very little adhesion between the Temflex and your hardware so when
> you want to rework the connection, it comes away very clean with no residue.
> Great system!
> 
> Dave
> 
> 
>> -Original Message-
>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf 
>> Of Ryan Stasel
>> Sent: Thursday, April 21, 2016 10:08
>> To: Discussion of precise time and frequency measurement
>> Subject: Re: [time-nuts] RG6 or LMR400 for GPS Antenna 
>> (Symmetricom 58532A and T-bolt)
>> 
>> All, 
>> 
>> Really awesome answers, thanks! 
>> 
>> For the sealing question, it was more of a "should I bother 
>> with something like anti-seize" or the like on the actual 
>> thread-thread N interface. The actual connector crimp, was 
>> planning on just using a couple layers of the heat-shrink 
>> with adhesive. That is all going to be internal to the mast 
>> anyway, so direct weather contact should be minimal. It's 
>> also on the side of my chimney, that gets very little to no 
>> direct sun, so UV exposure should be minimal. But good note
> 
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Re: [time-nuts] A new member & PN test set

[Mark Spencer]

Hi Oleg, I'd be interested in seeing more information about your phase noise 
measurement setup.

All the best
Mark Spencer
VE7AFZ

Sent from my iPhone

> On Mar 27, 2016, at 1:25 PM, Oleg Skydan <olegsky...@gmail.com> wrote:
> 
> Hi list,
> 
> I am in a process of making a low noise frequency synthesizer for the 1st LO
> for my new DSP HF transceiver (http://neon.skydan.in.ua). This list is not
> directly related to my project, but I found a lot of useful information in
> this list - thanks for all contributors!
> 
> I see a discussion regarding "$40 phase noise test set". I have built one and
> already use it for several months. It is a great help in design process (I
> am not "blind" anymore :) ). If somebody is interested I can share all the
> information about it.
> 
> Best wishes!
> Oleg 
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Re: [time-nuts] Fw: 5065

[Mark Spencer]

For those of us in Western Canada, I've purchased circular connectors at MRO 
electronics.

Best regards
Mark Spencer

Sent from my iPhone

> On Mar 17, 2016, at 9:29 PM, Clay Autery <caut...@montac.com> wrote:
> 
> Also Allied Electronics...  If I knew it was CPCs y'all were talking
> about...  same stuff we used in aviation, et al. for comms, nav aids, etc...
> 
> Also used in the oilfield for some equipment cables for data acquisition.
> 
> Plug:  https://www.alliedelec.com/te-connectivity-213905-1/70082887/
> Receptacle: https://www.alliedelec.com/te-connectivity-213889-2/70082884/
> 
> Pins, et al. are also available; look at the bottom of the pages...
> 
> If you can't find the exact 3 position plug/receptacle, you can always
> use a 4, 5, 6, etc... and simply plug the holes you aren't using...
> 
> __
> Clay Autery, KG5LKV
> MONTAC Enterprises
> (318) 518-1389
> 
>> On 3/17/2016 4:56 PM, J. L. Trantham wrote:
>> Ulrich,
>> 
>> The connectors can be obtained reasonably inexpensively from Galco.  
>> 
>> http://www.galco.com/shop/Circular-Connectors
>> 
>> They are a 3 pin circular connector, consisting of three parts, that are 
>> purchased as an 'insert', 'shell', and 'clamp', IIRC.  I don't have the part 
>> numbers in front of me but they are the same for the 5061 Cesium standards.
>> 
>> I can get you the specific part numbers if you can't find it in the archives.
>> 
>> I used a spare 3 wire extension cord and just cut the end off the cord and 
>> installed the connector to mate with the 5065A and 5061A.  I've been told 
>> that the wiring is different between the 5061A and some of the 5065A's but 
>> I've never found a 5065A that was different from my 5061A.
>> 
>> Might want to open the unit and make sure the wiring matches the schematic.
>> 
>> Good luck.
>> 
>> Joe
>> 
>> -Original Message-
>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of KA2WEU--- 
>> via time-nuts
>> Sent: Thursday, March 17, 2016 9:30 AM
>> To: time-nuts@febo.com
>> Subject: Re: [time-nuts] Fw: 5065
>> 
>> 
>> The HP 5065A Rubidium Frequency Standard requires  a circular 3 pin adapter 
>> cable that  can be plugged into 115V AC outlet. 
>> I checked all cables I have  and this particular cable  is not finable. Can 
>> the unit set to 110/220 V  
>> Maybe  this cable can be  purchased  or assembled ?   ULRICH  
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Re: [time-nuts] Best Rubidium Frequency Standard

[Mark Spencer]

I'd be curious in knowing what the correct settings to discipline a prs 10 are, 
even pointers and hints would be  very welcome.  I was never very happy with 
the performance of mine in that configuration vs simply letting it free run and 
periodically re syncing it (via the one pps input.)



All the best
Mark Spencer


Sent from my iPhone

> On Mar 12, 2016, at 3:11 PM, Charles Steinmetz <csteinm...@yandex.com> wrote:
> 
> jerry wrote:
> 
>> Is there any model-suffix or other identifier that would inform whether a 
>> used PRS-10 has the PPS sync input feature??
> 
> Not that I am aware of.  Not even the "customer part number" is a reliable 
> guide -- I have had several examples each of various CPNs, and some did have 
> the sync input feature and some did not.  (I've also seen examples of other 
> CPNs, *none* of which had the feature.  My sample hasn't been large enough to 
> conclude that none of them does, however.)
> 
> Re: how useful the feature is, if it is present: the PRS10 PLL is extremely 
> adjustable, and there are LOTS of combinations of settings that won't work 
> worth a damn with any particular external input.  So, finding a good 
> combination can be difficult, and finding the best combination can be elusive 
> at best to maddening (or worse).  Read the manual carefully, and pay 
> attention both to the default settings and to the hints that SRS provides.  
> With the right settings, a PRS10 *does* work extremely well with the PPS 
> input from a GPS.  They do generally take several days or more to lock, 
> because of the long time constants involved.
> 
> Best regards,
> 
> Charles
> 
> 
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Re: [time-nuts] GPS Outage..

[Mark Spencer]

I'd be curious to know how many carriers have a reference source other than GPS 
for their "data line sync."

A few decades ago when I worked with long haul data circuits for a living the 
use of in non GPS timing references still seemed fairly common in my view.

Yes I agree that some systems can run from "line timing" but a reference source 
is still needed some where.  
In my experience there was a common assumption made that the carriers had an 
accurate reference source for the timing that customers would pull "data line 
sync" from.

Later when I entered the time nuts hobby I saw lots of ex Telecom timing  gear 
for sale on the usual auction site.


All the best
Mark Spencer


> On Feb 27, 2016, at 4:51 AM, Bob Camp <kb...@n1k.org> wrote:
> 
> Hi
> 
>> On Feb 26, 2016, at 8:01 PM, Majdi S. Abbas <m...@latt.net> wrote:
>> 
>> On Fri, Feb 26, 2016 at 05:56:59PM -0500, Bob Camp wrote:
>>> Cell phones since they first came out have *never ever* been setup 
>>> to run on anything other than GPS. Retrofitting them to use something 
>>> else would take a decade or more. We didn’t “destroy the backup”, there 
>>> never was one. Pretty much all of our surplus gizmos are cell tower 
>>> surplus (like 99.99%).
>> 
>>Bob,
>> 
>>It depends.  
>> 
>>We're used to thinking of those GPS and oscillator packages
>> as the only timing for a cell site, but that was not the case until
>> fairly recently.
>> 
>>In many of those sites, there was also transport gear that
>> would take line timing from a CO or other site upstream that 
>> typically had diverse reference clocks available.  It might even 
>> have provided a backup BITS T1 as a frequency reference to cell
>> equipment.
>> 
>>Even without a local transport node, prior to the last few
>> years (where things seem to be going Ethernet), most cellular equipment
>> was still taking TDM handoffs, and could revert to taking line timing
>> off its transport circuits, thereby indirectly getting it from 
>> practically anything upstream if its local reference failed.
> 
> Again, the context of the question is an external to the system timing 
> source. In other words Loran-C or something similar. Even today, the network
> sync to the backbone does not come from the GPS. That comes from the 
> carrier’s data line sync. 
> 
> Bob
> 
> 
>> 
>>Certainly, the surplus device pool is all GPS, but that's
>> because of the number of additional devices deployed, not necessarily
>> representative of the full footprint of LORAN and other methods that
>> used to be available as indirect backup references for the sites.
>> 
>>Of course, that's not going to be an option going forwards.
>> I, for one, welcome our new Ethernet overlords.
>> 
>>--msa
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Re: [time-nuts] Introduction

[Mark Spencer]

I've found with my HP5370B's they perform best over a fairly narrow range of 
input signal levels.(1 to 2 volts If I recall correctly ?)  Some 
experiments might be in order for yours.   Virtually all my testing was done 
with 5 or 10 MHz sine waves so this may or may not be helpful in your case.   I 
found in line attenuators and an oscilloscope to be helpful in making 
measurements using my HP5370B's.

I've never done a full alignment of mine so this behaviour may not be typical.

All the best
Mark S


Sent from my iPhone

>> On Feb 24, 2016, at 1:36 AM, Bruce Griffiths  
>> wrote:
>> 
>> On Wednesday, February 24, 2016 12:55:42 AM Enrico Bellotti wrote:
>> Hello to all,
>> 
>> first of all, thank you for the great and useful work that the time-nuts
>> have done over the years.
>> 
>> I have finally been able to gather all my counters (HP5335A, HP51131A,
>> HP5370A, HP5370B #1, HP5370B #2) and try to do some "simple" measurements.
>> 
>> I have started testing and comparing the instruments I have available using
>> the approach that was discussed a while ago on the list and also outlined
>> by John Ackermann (http://www.febo.com/pages/hp5370b/). Specifically, the
>> Adev for a time interval measurement on a (90ft of) RG58A/U cable.
>> 
>> I have attached a PDF file with the results and some additional details of
>> the test setup.
>> 
>> From what I have understood the Adev at one second is related to the
>> counter resolution. The results I have obtained seem to be reasonable
>> except for HP5370B #2. This instrument seems to be marginal at best. Does
>> anybody know if the measured value for HP5370B #2 is a symptom of a
>> multifunction or simple need for calibration?
>> 
>> Thank you for any comments/suggestions/corrections you may have.
>> 
>> Best.
>> Enrico
> Try repeating the test with a low noise external reference/If that doesn't 
> improve the results try realigning the filters etc in the 10-200MHz 
> multiplier.
> 
> Bruce
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Re: [time-nuts] Abstract for consideration at 2016 New Mexico TechFest

[Mark Spencer]

Hi Cash.   

Here is a bit of a narrative and some comments from an amateur radio 
perspective.

I got into the time nuts hobby as off shoot from amateur radio.   I was using a 
pc sound card to evaluate the frequency stability of some of my ham radios by 
looking at the change in "beat note" when receiving wwv in SSB mode.

I realized that I couldn't use wwv as a frequency standard due to Doppler shift 
and in practice my radios with tcxo's were stable enough that it wasn't clear 
if I was seeing Doppler shift from wwv or the radios drifting.   

After some research I purchased a gpsdo from James Miller G3RUH which provided 
a suitable frequency source to replace wwv for my purposes.   Later I wanted to 
see accurate that GPSDO was.  To make a long story short

Ended up buying half a dozen HP5370 and HP5335 time interval counters a Jackson 
labs fury GPSDO, two Z3805 GPSDO's, a thunderbolt, a BVA, a FTS1050, an HP105, 
two time source 2700's (with prs 10 rb's) various stand alone rb's, ocxo's, 
various HP5328 counters with 10811 ocxo's, an NTP server etc.

Wrote  some scripts using Ulrich's plotter software to log the data to text 
files and processed the data using John's time lab software (thanks !).  

Couldn't quite convince my self to buy a cesium standard and a time pod 
(figured I would end up wanting to get two or three of each once I started down 
that road.)

I was (and am) more than satisfied with the performance of the G3RUH GPSDO for 
my amateur radio activities.

At the time work involved long periods of travel so collecting data for a few 
weeks at a time then looking at it later worked out ok.  Later I also had 
little time or interest for Amateur radio due to travel.

After a few years I decided to get back into amateur radio.   I still use the 
G3RUH gpsdo to check the frequency of my VHF and up gear.   It works well for 
this as it produces useable harmonics to over 1.3 GHz and it runs from a 13.8 
volt power source.  From time to time I still compare the G3RUH GPSDO to my 
other references.   

I have found for VHF and up weak signal work it is very helpful to have a 
suitable frequency standard.   

Regarding frequency calibration of my radios.  In practice listening to 
harmonics from the G3RUH GPSDO with the radio set to SSB mode and looking at 
the resulting audio frequency works well for me.  So far I've resisted the 
temptation to modify my radios to accept an external frequency reference, but 
checking their accuracy prior to use is part of my setup routine.   I suspect 
at some point I'll acquire radios that need an external reference source.   
I've ear marked a few ocxo's for this purpose.

Time synchronization is also important for some of the weak signal modes and 
having my own NTP server is helpful.

For amateur radio use (with some time nuts interest) two GPSDO's, a decent time 
interval counter and a frequency counter capable of measuring frequencies of 
interest (and able to accept an external frequency reference) along with a PC 
with a sound card is probably a good starting point IMHO.   A solution for time 
synchronization is also worth having especially for operations in locations 
without Internet connectivity.   A GPSDO with a one pps output can help 
facilitate this.

In terms of hints.   

Quality double shielded cables are useful.   Conversely cheap cables caused me 
various problems.

Terminating un used connections is also helpful.

A decent oscilloscope is useful for viewing wave forms and looking at signal 
levels.

In my experience getting the most performance out of gear such as the HP5370 
requires attention to detail re signal levels and trigger set points.   A 
selection of attenuators and a decent scope is helpful.

I also found using the BVA as the clock source for the HP5370's was helpful (vs 
using the built in 10811's.)

The prologix gpib to Ethernet adapters worked well for me.

If I was doing it again on a budget for ham radio use:

I'd probably still buy the G3RUH GPSDO, along with one other GPSDO.

I'd probably pass on the HP5370 series counters and look for a used HP53132 
counter and buy a dedicated frequency counter for measuring RF frequencies.  (I 
have no personal experience yet with the HP 53132 but it seems to be well 
regarded.)

I believe the HP5370's are getting a bit long in the tooth now.  I bought four 
working used ones and now have two that are fully functional.  I expect I could 
get at least one more working if tried.   I also needed a special pulse 
generator for the alignment procedure.   I picked up at least one of those as 
well.   In hindsight I'd probably settle for a bit less performance in return 
for (hopefully) less hassle and buy newer Hp 53132's.

Not sure I'd bother with the ocxo's, rb's etc until I had a definite need for 
that type of gear.

Doubt I'd ever buy a BVA for amateur radio use but I believe a clean FTS1050 
would be worthwhile if the price was right.   (The packaging, battery backup 
system, 

Re: [time-nuts] Phase noise from Allan Deviation ?

[Mark Spencer]

Yes.   I was not overly pleased with the performance of my 2700's.   I ended up 
pulling the PRS10 out of one of them and purchased the breakout connector board 
from SRS and used the resulting 10 MHz and 1 PPS outputs.From time to time 
I would sync the unit to one of my GPSDO's using the 1 PPS input.

I haven't powered up my 2700's in several years.


Your mileage may vary.


> On Dec 14, 2015, at 1:10 PM, Bob Camp  wrote:
> 
> Hi
> 
> One of the reasons the TS2700’s went out of favor is the “quality” of the 
> CDMA signals 
> available. The design assumption was that the CDMA carriers provided timing 
> as good 
> as GPS on their over the air systems. After the units had been in the field 
> for a while it
> became apparent that the 2700’s were not performing up to expectations. 
> Further investigation
> turned up a range of issues that degraded the CDMA timing relative to GPS. A 
> lot of it 
> boiled down to “we are a phone service not a time service”.  System wise, 
> CDMA gets 
> into trouble at the 10us level. GPS is in trouble at the 100 ns level….
> 
> Yes there are all sorts of rules and regulations. In the end it’s “this works 
> fine” that trumps
> a lot of them. 
> 
> Bob
> 
>> On Dec 14, 2015, at 1:15 PM, Charles Steinmetz  wrote:
>> 
>> Tom wrote:
>> 
>>> The 'unknown' is a Rubidium oscillator locked to CDMA pilot (TS2700)
>> 
>> There is very little information publicly available on the Symmetricom 
>> "BesTime" engine ("BTE"), but after playing with a few TS2700s for quite 
>> some time, including monitoring a number of internal signals, several things 
>> became apparent.  First, the 2700 does not seem to discipline the PRS10.  
>> The rubidium runs open loop and the BTE keeps track of the offset and the 
>> drift rate from "BTE time" (which is synthesized from all available sources 
>> -- however many CDMA signals it is receiving, plus any wireline telco timing 
>> signals and the PRS10 -- using a proprietary algorithm to estimate the 
>> reliability of each source and outputting BTE time and frequency using DDS). 
>>  Hobby users won't be feeding the unit any telco timing signals, so the BTE 
>> has only the CDMA signals to work from.  During holdover (and assuming no 
>> telco timing signals), the Rb is the sole input to the BTE, which uses the 
>> stored offset and drift to calculate BTE time.
>> 
>> I found that the TS-2700 is more than an order of magnitude less stable than 
>> a Trimble Thunderbolt, even with a full complement of rock-solid CDMA 
>> sources.  This may vary somewhat, depending on the CDMA equipment in use at 
>> any particular location and the diligence of the CDMA operator.
>> 
>> Best regards,
>> 
>> Charles
>> 
>> 
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Re: [time-nuts] RG 6 U couplings

[Mark Spencer]

I looked up the part number of the cable I installed and the data sheet says it 
does have Teflon insulation.  It does look different than other Teflon cables I 
have seen though. My main concern was and is the fire rating.  The comments 
about the phase stability are also of interest.   If anyone has this type of 
data for RG 6 style cables I'd be interested in seeing it.   

If I ever run new cables to the roof I might pull an new run of rg6 for the GPS.

At one point I was looking at ways to safely route non fire rated hard line to 
my GPS receiver.   


Sent from my iPhone

> On Dec 7, 2015, at 6:33 PM, Hal Murray  wrote:
> 
> 
> m...@alignedsolutions.com said:
>> Actually I may be misremembering this.Am not sure if the cable I used
>> was Teflon on not.   It did have a defined fire rating though, and I was
>> concerned about it's phase stability vis a vis temperatures.
> 
> I was at Xerox in the late '70s when the DEC-Intel-Xerox work on Ethernet was 
> going on.
> 
> The Los Angeles fire dept was sensitive to smoke from cables.  A friend got a 
> chunk of potential cable from Belden.  It was Teflon coated.  I don't know 
> what was inside.  He took it out on his back porch and hit it with a propane 
> torch.  It ignored him.  Well, not quite.  It got smudged a bit, but that 
> wiped off.
> 
> He took a bigger chunk to Underwriters Lab in Chicago.  They have a setup for 
> testing cables.  It's a cable tray in an enclosure that's 20 ft long and a 
> few feet wide and 3 or 4 feet tall.  A big gas pipe goes in one end.  There 
> is a chimney at the other.  They put the cable in, replace the lid and light 
> it up.  The Teflon cable didn't have any problems.
> 
> Teflon is expensive.  After a couple of years somebody worked out a cheaper 
> compound that was good enough for the fire people.
> 
> 
> -- 
> These are my opinions.  I hate spam.
> 
> 
> 
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Re: [time-nuts] RG 6 U couplings

[Mark Spencer]

Yep.   I used to worry about eliminating potential error sources such as that 
from my home lab.   On the flip side the Teflon cable I used did have a defined 
spec vis a vis behaviour in a fire that gave me some comfort when routing it 
thru my house on the way to the roof mounted antenna.   I also had it on hand.

Many items to consider.

If I was doing it again I'd probably just use 75 ohm RG6 CATV style cable with 
an appropriate fire rating for indoor / in home installations.   The local 
electronics store sells nice F female to (apparently 50 ohm) N male adapters 
that ease the interconnection issues if you can live with the impedance miss 
match.

Sent from my iPhone

> On Dec 7, 2015, at 11:23 AM, Bruce Griffiths <bruce.griffi...@xtra.co.nz> 
> wrote:
> 
>> On Sunday, December 06, 2015 10:02:43 AM Mark Spencer wrote:
>> I've seen data re delay vs temperature for high end 50 ohm cables.  I've
>> never seen it for 75 ohm CATV style cable.
>> 
>> Back when I was into time nuts pursuits this was one of the main
> reasons I
>> was contemplating switching my GPS antenna feed line to hardline.   I
> never
>> made the change but still have the hardline.
>> 
>> To this day I still use Teflon RG58 style cable (purchased surplus from
>> Boeing decades ago) for my GPS antenna fee line to the splitter.   I
> doubt
>> I will ever change it out.
>> 
>> Sent from my iPhone
>> 
>>> On Dec 6, 2015, at 4:21 AM, Attila Kinali <att...@kinali.ch> wrote:
>>> 
>>> On Sat, 5 Dec 2015 17:06:03 -0800
>>> 
>>> Mark Spencer <m...@alignedsolutions.com> wrote:
>>>> Over the years I've used a number of CATV style 75 ohm patch cords
>>>> with F connectors, F female to female couplers and F to other
> connector
>>>> adaptors to distribute gps signals from my GPS splitter to various
>>>> receivers.   I've never been able to notice any difference in reported
>>>> signal strength vs using "brand name" 50 ohm coax with N
> connectors.
>>> 
>>> Well, putting the numbers into a calculator gives:
>>> VSWR: 1.5
>>> Load Return loss: -14dB
>>> Load Mismatch Attenuation: -0.2dB
>>> 
>>> I'd say that for a receiver, this is quite negligible. Heck, even 1dB
>>> loss wouldn't hurt too much. I would suggest, that for all practical
>>> purposes, the use of (good) satellite coax cable would be more than
>>> good enough for most of us. The only thing i'm not sure about is how
>>> the delay through the cable behaves over time (aging, temperature,
>>> humidity). If anyone has some data on that, for different types of
>>> cables, I
>>> would appreciate getting a copy :-)
>>> 
>>>   Attila Kinali
>> 
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> Teflon has a phase transition around 20C or so.
> Consequently its phase stability isnt stellar near the transition.
> Polyethylene insulated cables are superior in this regard.
> 
> Bruce
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Re: [time-nuts] RG 6 U couplings

[Mark Spencer]

Actually I may be misremembering this.Am not sure if the cable I used was 
Teflon on not.   It did have a defined fire rating though, and I was concerned 
about it's phase stability vis a vis temperatures.


Sent from my iPhone

> On Dec 7, 2015, at 1:58 PM, Mark Spencer <m...@alignedsolutions.com> wrote:
> 
> Yep.   I used to worry about eliminating potential error sources such as that 
> from my home lab.   On the flip side the Teflon cable I used did have a 
> defined spec vis a vis behaviour in a fire that gave me some comfort when 
> routing it thru my house on the way to the roof mounted antenna.   I also had 
> it on hand.
> 
> Many items to consider.
> 
> If I was doing it again I'd probably just use 75 ohm RG6 CATV style cable 
> with an appropriate fire rating for indoor / in home installations.   The 
> local electronics store sells nice F female to (apparently 50 ohm) N male 
> adapters that ease the interconnection issues if you can live with the 
> impedance miss match.
> 
> Sent from my iPhone
> 
>>> On Dec 7, 2015, at 11:23 AM, Bruce Griffiths <bruce.griffi...@xtra.co.nz> 
>>> wrote:
>>> 
>>> On Sunday, December 06, 2015 10:02:43 AM Mark Spencer wrote:
>>> I've seen data re delay vs temperature for high end 50 ohm cables.  I've
>>> never seen it for 75 ohm CATV style cable.
>>> 
>>> Back when I was into time nuts pursuits this was one of the main
>> reasons I
>>> was contemplating switching my GPS antenna feed line to hardline.   I
>> never
>>> made the change but still have the hardline.
>>> 
>>> To this day I still use Teflon RG58 style cable (purchased surplus from
>>> Boeing decades ago) for my GPS antenna fee line to the splitter.   I
>> doubt
>>> I will ever change it out.
>>> 
>>> Sent from my iPhone
>>> 
>>>> On Dec 6, 2015, at 4:21 AM, Attila Kinali <att...@kinali.ch> wrote:
>>>> 
>>>> On Sat, 5 Dec 2015 17:06:03 -0800
>>>> 
>>>> Mark Spencer <m...@alignedsolutions.com> wrote:
>>>>> Over the years I've used a number of CATV style 75 ohm patch cords
>>>>> with F connectors, F female to female couplers and F to other
>> connector
>>>>> adaptors to distribute gps signals from my GPS splitter to various
>>>>> receivers.   I've never been able to notice any difference in reported
>>>>> signal strength vs using "brand name" 50 ohm coax with N
>> connectors.
>>>> 
>>>> Well, putting the numbers into a calculator gives:
>>>> VSWR: 1.5
>>>> Load Return loss: -14dB
>>>> Load Mismatch Attenuation: -0.2dB
>>>> 
>>>> I'd say that for a receiver, this is quite negligible. Heck, even 1dB
>>>> loss wouldn't hurt too much. I would suggest, that for all practical
>>>> purposes, the use of (good) satellite coax cable would be more than
>>>> good enough for most of us. The only thing i'm not sure about is how
>>>> the delay through the cable behaves over time (aging, temperature,
>>>> humidity). If anyone has some data on that, for different types of
>>>> cables, I
>>>> would appreciate getting a copy :-)
>>>> 
>>>>  Attila Kinali
>>> 
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>>> instructions there.
>> Teflon has a phase transition around 20C or so.
>> Consequently its phase stability isnt stellar near the transition.
>> Polyethylene insulated cables are superior in this regard.
>> 
>> Bruce
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Re: [time-nuts] RG 6 U couplings

[Mark Spencer]

Try not to laugh to hard but the compression connectors and crimper for RG6 
style cables I picked up at Home Depot in Canada a few years ago seems to work 
quite well.   

I have used high quality pro tools at work over the years (mostly though I 
watch other people use them on occasion these days (:  ). But the Home Depot 
one I purchased seems ok to me for home / hobby use.

As noted by others I believe it is important to match the tool to the 
connectors.

Sent from my iPhone

> On Dec 6, 2015, at 7:20 AM, F. W. Bray  wrote:
> 
> For those of us in the U.S., does anyone have suggestions of vendors or 
> brands of quality connectors and installation tools?
> 
> Over the years, I worked my way up from cheap wire terminals to PIDG 
> connectors and the correct tools.  Rather than repeat the process with F 
> connectors, I'm willing to pay a bit more the first time to do it right.
> 
> Fred
> KE6CD
> 
> Sent from my iPhone
> 
>> On Dec 6, 2015, at 4:44 AM, Bob Camp  wrote:
>> 
>> Hi
>> 
>> I agree 100% with the recommendation of compression connectors and of the 
>> CX3 in particular. The only thing I would add is that they require a proper 
>> tool
>> to “compress” them. I have found that some of the tools are pretty brand 
>> specific.
>> You may need to match the tool to the connector.
>> 
>> Bob
>> 
>>> On Dec 5, 2015, at 11:38 PM, Arnold Tibus  wrote:
>>> 
>>> Hi Bert and the group,
>>> 
>>> I can highly recommend the so called compression F-connectors.
>>> There are a lot of brands out, but my personal favorite is the
>>> Waterproof CX3 Quickmount
>>> from Corning Cabelcon, because they have very good rf and mechanical data.
>>> They are not only weatherproof and corrosion resistant (NiTin-alloy), but
>>> they are really watertight (tested 8h at 30m) and accept a quite high
>>> pull strength of up to typical 480N.
>>> The RF shielding and impedance data are also very good.
>>> 
>>> For outside I use successful since years a black polyethylen insulated
>>> cable
>>> which is really weatherproof and UV resistant and triple shielded with
>>> tinned copper
>>> braid (I don't like aluminum braid because the low mech. performance).
>>> 
>>> Just for overview information (I have no relation to this company!):
>>> http://www.cabelcon.dk/download/CX3Folder_May2012.pdf
>>> 
>>> One may find similar connectors made by other companies.
>>> 
>>> The only 'negative' point is the need of a compression tool.
>>> 
>>> So I think this would be a very good solution for repair and connection
>>> in general of RG6 and similar types also for GPS use.
>>> 
>>> Kind regards
>>> 
>>> Arnold, DK2WT
>>> 
>>> 
>>> 
 Am 05.12.2015 um 21:28 schrieb Bert Kehren via time-nuts:
 At my new home the GPS antenna location has turned in to a  challenge.  
 May 
 have to splice RG 6U. Has any one done measurements on  couplings and the 
 loss associated with them. Right now I am considering a  female, female 
 coupling. Is there a better alternative?
 Thanks   Bert Kehren Palm City  Fl.
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>> 
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Re: [time-nuts] RG 6 U couplings

[Mark Spencer]

I've seen data re delay vs temperature for high end 50 ohm cables.  I've never 
seen it for 75 ohm CATV style cable.

Back when I was into time nuts pursuits this was one of the main reasons I was 
contemplating switching my GPS antenna feed line to hardline.   I never made 
the change but still have the hardline.   

To this day I still use Teflon RG58 style cable (purchased surplus from Boeing 
decades ago) for my GPS antenna fee line to the splitter.   I doubt I will ever 
change it out.

Sent from my iPhone

> On Dec 6, 2015, at 4:21 AM, Attila Kinali <att...@kinali.ch> wrote:
> 
> On Sat, 5 Dec 2015 17:06:03 -0800
> Mark Spencer <m...@alignedsolutions.com> wrote:
> 
>> Over the years I've used a number of CATV style 75 ohm patch cords
>> with F connectors, F female to female couplers and F to other connector
>> adaptors to distribute gps signals from my GPS splitter to various
>> receivers.   I've never been able to notice any difference in reported
>> signal strength vs using "brand name" 50 ohm coax with N connectors.
> 
> Well, putting the numbers into a calculator gives:
> VSWR: 1.5
> Load Return loss: -14dB
> Load Mismatch Attenuation: -0.2dB
> 
> I'd say that for a receiver, this is quite negligible. Heck, even 1dB
> loss wouldn't hurt too much. I would suggest, that for all practical
> purposes, the use of (good) satellite coax cable would be more than
> good enough for most of us. The only thing i'm not sure about is how
> the delay through the cable behaves over time (aging, temperature, humidity).
> If anyone has some data on that, for different types of cables, I
> would appreciate getting a copy :-)
> 
>Attila Kinali
> 
> -- 
> It is upon moral qualities that a society is ultimately founded. All 
> the prosperity and technological sophistication in the world is of no 
> use without that foundation.
> -- Miss Matheson, The Diamond Age, Neil Stephenson
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Re: [time-nuts] PRS10 1 PPS Out having random phase jumps

[Mark Spencer]

I don't recall ever having this issue with mine.  As a general rule though I 
seemed to have more success using 5 and 10 MHz reference signals vs 1 pps 
reference signals with my HP5370's and HP5335's when making Adev measurements 
of 5 and 10 MHz OCXO's.

Sent from my iPhone

> On Nov 23, 2015, at 12:11 PM, James Robbins  wrote:
> 
> Has anyone using the 1 PPS output from a PRS10 rubidium found significant
> random phase jumps?  I'm getting these random phase jumps while using the
> PRS10 as a TI base for ADEV.  I can use the 10 MHz output of the PRS10 to
> feed a T2mini without any similar jumps.  Wondering if it might be heat
> related or other.  Needless to say, such jumps screw up the TI ADEV readings
> and convert the TimeLab readings from the E-12 range to E-1 or so.  Thanks.
> 
> 
> 
> Jim Robbins
> 
> N1JR
> 
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Re: [time-nuts] UPS for my time rack

[Mark Spencer]

Sorry for a somewhat Non time nuts posting but this topic seems to have drawn a 
lot of interest.

I found the Microsoft article fascinating.   Thanks for sharing.  

Re DC power.   I've seen some computing equipment that ran from -48 volts DC 
but to expand on the comments from PHK about DC power it never really seemed to 
catch on in the Enterprise space.   The need to deal with actual wiring issues 
vs simply plugging in an AC power cord was a major obstacle in my view, but 
there were others as well in my view.

(Years ago I did a quick assessment of building a data centre that would have 
largely used -48 volt DC power.   We didn't proceed with the project.)

To return to a time nuts focus:
One of the things I like about much of my time nuts gear is that it runs from 
24 Volts D.C.  At this point though the only gear I have powered by my backup 
battery system is gear that already has a backup 24 Volt power connection.   

I've toyed with the idea of constructing a simple change over system to quickly 
switch from the AC line powered supplies to the backup battery system for the 
gear that doesn't have backup power inputs.   

(I briefly considered running the gear from the batteries full time but I'm 
concerned that some equipment really wants to see 24 volts not the 27.5 thru 28 
volts or so that is required to charge the batteries.  My BVA oscillator is a 
particular concern for me in this regard.)





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Sent from my iPhone

> On Oct 13, 2015, at 11:54 AM, Poul-Henning Kamp  wrote:
> 
> 
> In message <4FD0F30EBAEF49609DF207E3EE61C15B@pc52>, "Tom Van Baak" writes:
> 
> 
>> I used to rely on one massive UPS (along with natural gas generator)
>> for my entire lab. Eventually I found it more reliable and convenient
>> to have localized power backup. By local I mean backup for a single
>> shelf, or even a single instrument.
> 
> The big gain is avoiding the DC->AC conversions.
> 
> AC->DC conversions are covered under EnergyStar and similar programmes,
> so they're generally 90% efficient or better.
> 
> But DC->AC conversions, for instance in inverters and UPS's are not
> covered, the argument going that they are only run very seldomly,
> and therefore capital cost would be wasted.
> 
> In the professional segment, UPS's which require a forklift,
> efficiencies are good, in some cases very good, because power costs
> money at that scale.
> 
> But anyting you can fit into a rack will typically have horrible
> losses, the smaller the UPS the worse.  I've personally measured
> sub 50% efficiency in one case.
> 
> The argument against running stuff on 12 or 24V DC is the short
> circuit currents, and the absense of an affordable standarized
> connector.
> 
> For the short circuit currents the only cure is fuses and caution,
> and for connectors there seems to be no hope of a standard - ever.
> 
> China forced USB through as the standard for mobile phones, but
> despite several valiant attempts nobody has ever managed to get
> anything above 5V/5W standardized.
> 
> Here's the website of the IEEE WG which came out with a standard
> (IEEE 1823:2015) this May:
> 
>http://grouper.ieee.org/groups/msc/upamd/
> 
> It will cost you $160 to see the full standard, which is a very
> good and strong reason why adoption will be slow, and nobody
> I've talked to expects it to go anywhere ever.
> 
> At the same time USB has come up with 100W power concept
> which is not compatible, since IEEE uses CANbus and different
> connectors.
> 
> I've not heard any rumours that China man nail this one.
> 
> 
> -- 
> Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
> p...@freebsd.org | TCP/IP since RFC 956
> FreeBSD committer   | BSD since 4.3-tahoe
> Never attribute to malice what can adequately be explained by incompetence.
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Re: [time-nuts] UPS for my time rack

[Mark Spencer]

I've also seen inverter systems that are designed for stand by power use in 
service at commercial sites in third world countries.  Within reason they 
basically let you run what ever reasonable arrangement of rechargeable lead 
acid based batteries you want that will supply the required voltage and 
current.  They handle the conversion of dc to ac and the switch over from 
commercial to inverter power.   They usually also feature a basic battery 
charger with settings to charge various types of batteries (ie, gel or 
conventional lead acid.)

Typically I've seen them used with a number of automotive style batteries.

The users would need to sort out the necessary cables, fuses, batteries, deal 
with safety considerations etc.

I've never seen these devices in Canada or the U.S.  Sort of a value engineered 
UPS system for price conscious markets.  Might be a nice starting point for 
those who want to role their own system and can deal with the safety aspects of 
this.   I'm not sure what the transfer time from utility to inverter power 
would be.

In the U.S. and Canada the typical practice seems to be to use packaged UPS 
systems that include their own batteries.  


Sent from my iPhone

> On Oct 11, 2015, at 10:36 AM, Bob Benward  wrote:
> 
> Dave, 
> You could use a 120V relay and switch the high capacity battery from its own
> charger to the battery pack in the UPS.  When power comes back, the relay
> automatically switches the battery out and back to its own charger.
> 
> Bob
> 
 -Original Message-
 From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Dr.
 David Kirkby (Kirkby Microwave Ltd)
 Sent: Saturday, October 10, 2015 6:07 PM
 To: Discussion of precise time and frequency measurement
 Subject: Re: [time-nuts] UPS for my time rack
 
> On 10 October 2015 at 14:20, Chris Waldrup  wrote:
> 
> Hi,
> 
> 
> I have decided I'd like to get a UPS to put on the rack containing my
> Thunderbolt, the laptop that runs Lady Heather, and frequency counter.
 
 There's one issue with them that I don't see anyone mention.
 
 I was thinking of doing the same a while back, and intended getting a
> UPS
 and adding a large external battery pack, so if the mains failed late at
> night, I
 could run the GPS receiver and a few other things overnight, and
> consider
 starting the generator in the morning.  I contacted a dealer on eBay,
> who
 specilaises in UPSs. He told me that the smaller units with built in
> batteries
 will die if you put large external batteries on them.
 Essentially the charging circuits are not designed to run as long as
> needed to
 charge big batteries. Even on ones designed for external batteries,
> there's a
 recommended limit on the size of them. So if you think you might want to
 increase runtime by adding some batteries, buy one designed for that
> service.
 
 I've had two here which were HP/Compaq 5 kW units. These were different
 to the normal, in that the batteries added up to over 300 V, so could
> produce
 240 VAC with no need to step it up. Both these blew up on me, for
> reasons I
 never worked out. The load was never anywhere near 5 kW.
 
 Lots of people mention sine wave. Of course, if you keen enough, you
> could
 make a class A amplifier and sine wave oscillator. The problem is that
> the
 pure sine wave inverters tend to be very inefficient.
 
 As with most things, there are a lot of things to balance - runtime,
> cost,
 quality of output, audio noise, RFI  etc etc.
 
 Dave
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 No virus found in this message.
 Checked by AVG - www.avg.com
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 10/09/15
> 
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Re: [time-nuts] UPS for my time rack

[Mark Spencer]

Yes this is a complex topic.   At one point in my career when I was responsible 
for the up time of several data centres for a high tech firm I had an 
Electrical Engineer on my team to (amongst other roles) work thru the various 
issues pertaining to UPS systems.   I recall there were significant differences 
between the various UPS designs.

Getting out of high tech and into an industry where data centres were out 
sourced was a nice change for me (:

To relate this to time nuts, those of us looking at making significant 
investments in this type of equipment would do well to seek out the advice of 
those who are knowledgable.

Sent from my iPhone

> On Oct 10, 2015, at 7:51 AM, Bob Camp  wrote:
> 
> Hi
> 
> All of the UPS vendors these days make a wide range of products. They range 
> from 
> low cost to mighty expensive. They also range a bit in terms of performance. 
> Finding out
> exactly what this or that model *does* do can be a major pain. The marketing 
> guys apparently
> don’t want you to figure out that the low cost gizmo does not have all the 
> performance 
> of the one that costs 5 times as much. 
> 
> First thing to avoid - the pure square wave output versions. These may or may 
> not
> generate RFI in this or that UHF band. They will take out big chunks of HF 
> and mess up 10 MHz
> distribution. I suspect that the filters on some are better than the filters 
> on others. The bigger issue
> is that they do not play nice with modern power factor corrected power 
> supplies. These supplies 
> seem to expect a sine wave and a (possibly ringing) square wave may get them 
> confused.
> 
> Next thing to avoid - The stepped square wave / modified square wave 
> versions. Theses aren’t 
> quite as bad as the centuries old square wave units. It’s more likely you 
> will find these than a 
> pure square. They still have the same issues on RFI. They may or may not 
> antagonize a PFC 
> supply to the same extent. 
> 
> The target is a “pure sine wave” output. That keeps a PFC supply happy. As 
> with any verbal spec, 
> “pure” likely has a few qualifiers on it. It’s not guaranteed to take out the 
> RFI. It at least will reduce 
> the spikes on your 1 pps lines. If you look at the output on a ’scope the 
> waveform at least *looks* like
> a sine wave. 
> 
> All of these gizmos run a switcher in the “few hundred KHz” range to generate 
> the output. They run 
> a similar switcher to charge the battery. None of them are compatible with an 
> indoor antenna in the same
> room trying to listen to MF. None of the ones I have tried are nasty enough 
> to bother GPS, either indoor or
> outdoor. Put another way, I’ve had more trouble from LED lights than from 
> sine wave UPS’s. 
> 
> Cyber Power (via Amazon) seems to make some pretty good stuff at a price 
> point a bit below APC. As
> with everybody else, it’s a pain to figure out what’s what. Are you after a 
> “big” rack mount unit (as in $500
> and up) or something smaller?
> 
> Bob 
> 
> 
>> On Oct 10, 2015, at 9:20 AM, Chris Waldrup  wrote:
>> 
>> Hi,
>> 
>> 
>> I have decided I'd like to get a UPS to put on the rack containing my 
>> Thunderbolt, the laptop that runs Lady Heather, and frequency counter. 
>> Has anyone had bad experience noise wise with the APC brand units like are 
>> available on Amazon and at Staples? I'd like to get one that doesn't 
>> generate lots of RFI. Thank you. 
>> 
>> 
>> Chris
>> KD4PBJ
>> 
>> —
>> Sent from Mailbox
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Re: [time-nuts] UPS for my time rack

[Mark Spencer]

I'm fortunate that several of pieces of my time nuts gear (including two of my 
ocxo's) feature backup 24 volt dc power inputs.   They were the only things in 
my house that stayed running during a recent 2 day power outage while I was 
away.

I have two large 12 volt gel cells in series that I re charge from time to time 
with a power supply via a blocking diode.

I agree about the importance of the fusing.  I've also found it's easy to buy 
fuses rated to work on 12 and 24 volt dc systems, fuses for 48 volt and higher 
dc systems are harder to find.

I also bolt the fuses directly to the battery terminals.

Sent from my iPhone

> On Oct 10, 2015, at 9:31 AM, Alex Pummer  wrote:
> 
> for a very similar application I am using a solar panel to charge the 
> battery, but I have a vented NiFe battery, which is not sensitive of over 
> charging or deep discharging, and has almost unlimited life time -- I have 
> seen some in forklifts which were 60 years old and working...
> 73
> KJ6UHN
> Alex
> 
> 
> 
>> On 10/10/2015 7:14 AM, Poul-Henning Kamp wrote:
>> 
>> In message <183218108.6a07c91c@Nodemailer>, "Chris Waldrup" writes:
>> 
>> 
>>> Has anyone had bad experience noise wise with the APC brand units
>>> like are available on Amazon and at Staples? I'd like to get one
>>> that doesn't generate lots of RFI. Thank you.
>> Then don't.
>> 
>> Instead get 12 or 24 Volt sealed lead-acid batteries and a good
>> float-charger, and run your stuff from that.
>> 
>> You avoid a lot of conversion losses, and you get to decide what
>> quality batteries you want (As opposed to "the cheapest we can get
>> away with") and you get to decide how long hold-up time you want.
>> 
>> The important tricks are:
>> 
>>   1. ATO Fuse *RIGHT NEXT TO THE BATTERY*.  Not a meter away, but
>>  quite literally bolted right onto the terminal.
>> 
>>   2. Don't buy a shit charger, it will cost you battery life.
>> 
>>   3. Suitably sized fuse/polyfuses on all loads.
>> 
>>   4. Either put 0.010 Ohm current shunts in all over the place
>>  or buy a 1mA resolution clamp meter and prepare the wiring
>>  for measurement.
>> 
>> And that's it really...
>> 
>> I run all the always-on stuff in my lab from two 12V/105Ah telco-grade
>> sealed lead-acid batteries, and I'll never look back.
>> 
>> Presenty the load is 6.7A @ 24V, and that powers my ADSL lines,
>> firewalls (soekris), home server (ITX with mini-box.com PSU),
>> emergency lights (LED strips), GPS, GPSDO, HP5065 etc. etc.
> 
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Re: [time-nuts] UPS for my time rack

[Mark Spencer]

Hi over the last 10 years or so I've purchased several consumer / small office 
grade UPS's from sources such as Staples and Costco.   I've never noted any RFI 
from them but I live in a (rf) noisy urban neighbourhood so any noise they put 
out is probably hard to notice.

Other than occasionally turning some of them off and on and seeing if I can see 
or hear any (additional) RFI on frequencies of interest I've never really 
looked for RFI from them.   

Several years ago I started putting ferrite chokes on the feed lines for my 
antennas and have almost completely  switched to double shielded cables for my 
amateur radio and time nuts activities.

Hope these comments are of some interest.

Mark S
VE7AFZ


Sent from my iPhone

> On Oct 10, 2015, at 6:20 AM, Chris Waldrup  wrote:
> 
> Hi,
> 
> 
> I have decided I'd like to get a UPS to put on the rack containing my 
> Thunderbolt, the laptop that runs Lady Heather, and frequency counter. 
> Has anyone had bad experience noise wise with the APC brand units like are 
> available on Amazon and at Staples? I'd like to get one that doesn't generate 
> lots of RFI. Thank you. 
> 
> 
> Chris
> KD4PBJ
> 
> —
> Sent from Mailbox
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Re: [time-nuts] UPS for my time rack

[Mark Spencer]

A quick comment about "pure sine" devices.

At times I operate a portable VHF and up radio system from rf quiet out of the 
way places.   I run almost all the equipment from lead acid storage batteries.  
 I have small 30 dollar inverter I use to occasionally  power some equipment 
that needs 120 volts AC.   It puts out very little RFI.   I figured I'd upgrade 
to a much more expensive pure sine Inverter (I also wanted to run some linear 
power supplies from the inverter as well to get better voltage regulation for 
some of the equipment.)  It was a disaster from an RFI perspective.


Your mileage may vary.

Mark S
VE7AFZ

Sent from my iPad

On 2015-10-10, at 7:51 AM, Bob Camp  wrote:

> Hi
> 
> All of the UPS vendors these days make a wide range of products. They range 
> from 
> low cost to mighty expensive. They also range a bit in terms of performance. 
> Finding out
> exactly what this or that model *does* do can be a major pain. The marketing 
> guys apparently
> don’t want you to figure out that the low cost gizmo does not have all the 
> performance 
> of the one that costs 5 times as much. 
> 
> First thing to avoid - the pure square wave output versions. These may or may 
> not
> generate RFI in this or that UHF band. They will take out big chunks of HF 
> and mess up 10 MHz
> distribution. I suspect that the filters on some are better than the filters 
> on others. The bigger issue
> is that they do not play nice with modern power factor corrected power 
> supplies. These supplies 
> seem to expect a sine wave and a (possibly ringing) square wave may get them 
> confused.
> 
> Next thing to avoid - The stepped square wave / modified square wave 
> versions. Theses aren’t 
> quite as bad as the centuries old square wave units. It’s more likely you 
> will find these than a 
> pure square. They still have the same issues on RFI. They may or may not 
> antagonize a PFC 
> supply to the same extent. 
> 
> The target is a “pure sine wave” output. That keeps a PFC supply happy. As 
> with any verbal spec, 
> “pure” likely has a few qualifiers on it. It’s not guaranteed to take out the 
> RFI. It at least will reduce 
> the spikes on your 1 pps lines. If you look at the output on a ’scope the 
> waveform at least *looks* like
> a sine wave. 
> 
> All of these gizmos run a switcher in the “few hundred KHz” range to generate 
> the output. They run 
> a similar switcher to charge the battery. None of them are compatible with an 
> indoor antenna in the same
> room trying to listen to MF. None of the ones I have tried are nasty enough 
> to bother GPS, either indoor or
> outdoor. Put another way, I’ve had more trouble from LED lights than from 
> sine wave UPS’s. 
> 
> Cyber Power (via Amazon) seems to make some pretty good stuff at a price 
> point a bit below APC. As
> with everybody else, it’s a pain to figure out what’s what. Are you after a 
> “big” rack mount unit (as in $500
> and up) or something smaller?
> 
> Bob 
> 
> 
>> On Oct 10, 2015, at 9:20 AM, Chris Waldrup  wrote:
>> 
>> Hi,
>> 
>> 
>> I have decided I'd like to get a UPS to put on the rack containing my 
>> Thunderbolt, the laptop that runs Lady Heather, and frequency counter. 
>> Has anyone had bad experience noise wise with the APC brand units like are 
>> available on Amazon and at Staples? I'd like to get one that doesn't 
>> generate lots of RFI. Thank you. 
>> 
>> 
>> Chris
>> KD4PBJ
>> 
>> —
>> Sent from Mailbox
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Re: [time-nuts] UPS for my time rack

[Mark Spencer]

Just to add to this.  I've also been told that other pure sine inverters have 
worked well for others in similar applications. 

Not sure if mine was unusually bad or the frequencies it operated on happened 
to be related to the frequencies I was using.

Your success may vary.   

Best regards
Mark S

Sent from my iPhone

> On Oct 10, 2015, at 8:26 AM, Mark Spencer <m...@alignedsolutions.com> wrote:
> 
> A quick comment about "pure sine" devices.
> 
> At times I operate a portable VHF and up radio system from rf quiet out of 
> the way places.   I run almost all the equipment from lead acid storage 
> batteries.   I have small 30 dollar inverter I use to occasionally  power 
> some equipment that needs 120 volts AC.   It puts out very little RFI.   I 
> figured I'd upgrade to a much more expensive pure sine Inverter (I also 
> wanted to run some linear power supplies from the inverter as well to get 
> better voltage regulation for some of the equipment.)  It was a disaster from 
> an RFI perspective.
> 
> 
> Your mileage may vary.
> 
> Mark S
> VE7AFZ
> 
> Sent from my iPad
> 
>> On 2015-10-10, at 7:51 AM, Bob Camp <kb...@n1k.org> wrote:
>> 
>> Hi
>> 
>> All of the UPS vendors these days make a wide range of products. They range 
>> from 
>> low cost to mighty expensive. They also range a bit in terms of performance. 
>> Finding out
>> exactly what this or that model *does* do can be a major pain. The marketing 
>> guys apparently
>> don’t want you to figure out that the low cost gizmo does not have all the 
>> performance 
>> of the one that costs 5 times as much. 
>> 
>> First thing to avoid - the pure square wave output versions. These may or 
>> may not
>> generate RFI in this or that UHF band. They will take out big chunks of HF 
>> and mess up 10 MHz
>> distribution. I suspect that the filters on some are better than the filters 
>> on others. The bigger issue
>> is that they do not play nice with modern power factor corrected power 
>> supplies. These supplies 
>> seem to expect a sine wave and a (possibly ringing) square wave may get them 
>> confused.
>> 
>> Next thing to avoid - The stepped square wave / modified square wave 
>> versions. Theses aren’t 
>> quite as bad as the centuries old square wave units. It’s more likely you 
>> will find these than a 
>> pure square. They still have the same issues on RFI. They may or may not 
>> antagonize a PFC 
>> supply to the same extent. 
>> 
>> The target is a “pure sine wave” output. That keeps a PFC supply happy. As 
>> with any verbal spec, 
>> “pure” likely has a few qualifiers on it. It’s not guaranteed to take out 
>> the RFI. It at least will reduce 
>> the spikes on your 1 pps lines. If you look at the output on a ’scope the 
>> waveform at least *looks* like
>> a sine wave. 
>> 
>> All of these gizmos run a switcher in the “few hundred KHz” range to 
>> generate the output. They run 
>> a similar switcher to charge the battery. None of them are compatible with 
>> an indoor antenna in the same
>> room trying to listen to MF. None of the ones I have tried are nasty enough 
>> to bother GPS, either indoor or
>> outdoor. Put another way, I’ve had more trouble from LED lights than from 
>> sine wave UPS’s. 
>> 
>> Cyber Power (via Amazon) seems to make some pretty good stuff at a price 
>> point a bit below APC. As
>> with everybody else, it’s a pain to figure out what’s what. Are you after a 
>> “big” rack mount unit (as in $500
>> and up) or something smaller?
>> 
>> Bob 
>> 
>> 
>>> On Oct 10, 2015, at 9:20 AM, Chris Waldrup <kd4...@gmail.com> wrote:
>>> 
>>> Hi,
>>> 
>>> 
>>> I have decided I'd like to get a UPS to put on the rack containing my 
>>> Thunderbolt, the laptop that runs Lady Heather, and frequency counter. 
>>> Has anyone had bad experience noise wise with the APC brand units like are 
>>> available on Amazon and at Staples? I'd like to get one that doesn't 
>>> generate lots of RFI. Thank you. 
>>> 
>>> 
>>> Chris
>>> KD4PBJ
>>> 
>>> —
>>> Sent from Mailbox
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Re: [time-nuts] New Symmetricom 58532A antennas - Launch3

[Mark Spencer]

Hi I have one of the masts, it's just a piece of tubing.  According to the 
instructions that came with my antenna the mast has an outer diameter of 42mm,  
I would expect a metal supply store could supply a suitable piece of pipe or 
tubing ?

Hex screws in the base of the antenna clamp the antenna to what ever mast you 
use.


Regards
Mark S
Sent from my iPhone

> On Oct 2, 2015, at 6:01 AM, Steve  wrote:
> 
> The Symmetricom data sheet mentions the Option AUB antenna mast. What is 
> that? I don't find details of it. How does you mount the 58532A antenna if 
> the Option AUB mast is not available?
> 
> Steve, K8JQ
> 
>> On 10/1/2015 3:19 PM, Gregory Beat wrote:
>> I received this e-mail earlier today (below) from Launch3.
>> Launch3 has been selling surplus/overstock cellular/telecom equipment.
>> They currently have a LARGE supply (~750) of surplus Symmetricom 58532A 
>> antennas.
>> 
>> Symmetricom 58532A GPS Antenna -- Datasheet
>> http://www.microsemi.com/document-portal/doc_view/133381-58532a
>> 
>> I acquired one of these antennas 2 weeks ago, they are brand new in box.
>> My 58532A antenna is currently connected to a Symmetricom/Datum TS2100 GPS 
>> w/Heol N024 receiver upgrade.
>> 
>> Check their web site and contact them (web page info), with number you 
>> desire,
>> so they can determined shipping charges.
>> 
>> Greg
>> w9gb
>> 
>> From: Launch3
>> 
>> Hello
>>  You previously purchased or inquired about the Symmetricom 58532A GPS 
>> Antennas, we are currently liquating all 750 of them.
>> They are all New in Box and the price is $25 each + Shipping
>> 
>> Link to the part -  https://www.launch3telecom.com/symmetricom/58532a.html
>>  Launch3Telecom.com
>> Launch3Services.com
>> 27 Daniel Rd.
>> Fairfield, New Jersey 07004
>> 
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Re: [time-nuts] Z3805 service information ?

[Mark Spencer]

Thanks Bob.   No I haven't cracked open the case yet.  Once I saw rs 232 data 
and confirmed that the docxo was still working as well as before from an adev 
perspective I shelved the unit.   One day I may try and swap GPS receivers and 
power supplies with another unit but for now  it goes into the project pile.   
The docxo in that unit is almost as good as my fts1050 at short tau's.   It was 
by far the best GPSDO I had from an adev perspective but I haven't done much 
with it for the last few years.

Re the Lightning the unit did work after the storm but I thought it was odd 
that only that unit lost lock while three other gpsdo's connected to the same 
antenna via the same four port splitter worked without a hitch.  

This is also the same unit that failed after the power went out.

They all run from the same ups as well.

Thanks for the hint re the z38xx program.   I have not used that in a while.  I 
usually use GPScon.
Sent from my iPhone

> On Sep 8, 2015, at 8:57 PM, Bob Benward <rbenw...@verizon.net> wrote:
> 
> Hi Mark,
> I suspected my GPS was trashed after the storm as well.  So I swapped the
> GPS model between my Z3801A and Z3805A.  I monitored both at the same time
> and both eventually got GPS locks.  My antennae are not optimally placed so
> that may be why it takes so long.  So much for that idea.  As I said before
> in my case it the ocxo running out of EFC range.  Did you check the supply
> voltages via the test points?
> 
> 
> Bob
> 
> P.S. Something I learned about the Z38xx program:  If you need to run two
> copies on the same computer, simply place then in different folders.  The
> data and init folders remain within the folders allowing you to run two
> different Z38xx machines on different com ports.
> 
>>>> -Original Message-
>>>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Mark
>>>> Spencer
>>>> Sent: Tuesday, September 08, 2015 4:41 PM
>>>> To: Discussion of precise time and frequency measurement
>>>> Subject: Re: [time-nuts] Z3805 service information ?
>>>> 
>>>> Hi it seems the GPS module is not working and I suspect the power supply
> is
>>>> failing.   After a few power cycles the unit started up and reported via
> rs232
>>>> that it could not communicate with the GPS receiver
>>>> 
>>>> The docxo still delivers great performance from an adev perspective and
> I
>>>> have other gpsdo's so I'm going to defer any more work on this for the
> time
>>>> being.  The docxo is probably the most valuable part right now.  It is
> far and
>>>> away better than any of my other 10811's from an adev perspective.
>>>> 
>>>> Right now I'm kind of glad no one bought my jackson labs fury GPSDO.
>>>> 
>>>> 
>>>> I figure I got my money's worth from the Z3805 and my interest in time
> nuts
>>>> pursuits has waned in recent years.
>>>> 
>>>> Also I seem to recall this Z3805 loosing GPS lock during a lightning
> storm as
>>>> well.  (I recall some one else mentioned this issue with their Z3805.)
>>>> 
>>>> 
>>>> Sent from my iPhone
>>>> 
>>>>> On Sep 1, 2015, at 9:05 PM, Bob Benward <rbenw...@verizon.net> wrote:
>>>>> 
>>>>> Can you communicate over RS232?  Are you using the Z38xx software?
>>>>> What does it say?
>>>>> 
>>>>> Bob
>>>>> 
>>>>>>>> -Original Message-
>>>>>>>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of
>>>>>>>> Mark Spencer
>>>>>>>> Sent: Tuesday, September 01, 2015 12:54 PM
>>>>>>>> To: time-nuts@febo.com
>>>>>>>> Subject: [time-nuts] Z3805 service information ?
>>>>>>>> 
>>>>>>>> Hi, I realize this is a long shot but I'm curious if anyone has
>>>>>>>> ever
>>>>> come across
>>>>>>>> any form of a service manual (or insight into a power on self test
>>>>> routine) for
>>>>>>>> the Z3805 gpsdo ?
>>>>>>>> 
>>>>>>>> One of mine is not working properly after being power cycled.   It
> works
>>>>> well
>>>>>>>> enough to blink the status lights on the front panel hence my
>>>>>>>> request
>>>>> for info
>>>>>>>> about

Re: [time-nuts] Z3805 service information ?

[Mark Spencer]

Hi it seems the GPS module is not working and I suspect the power supply is 
failing.   After a few power cycles the unit started up and reported via rs232 
that it could not communicate with the GPS receiver

The docxo still delivers great performance from an adev perspective and I have 
other gpsdo's so I'm going to defer any more work on this for the time being.  
The docxo is probably the most valuable part right now.  It is far and away 
better than any of my other 10811's from an adev perspective.

Right now I'm kind of glad no one bought my jackson labs fury GPSDO.


I figure I got my money's worth from the Z3805 and my interest in time nuts 
pursuits has waned in recent years.

Also I seem to recall this Z3805 loosing GPS lock during a lightning storm as 
well.  (I recall some one else mentioned this issue with their Z3805.) 


Sent from my iPhone

> On Sep 1, 2015, at 9:05 PM, Bob Benward <rbenw...@verizon.net> wrote:
> 
> Can you communicate over RS232?  Are you using the Z38xx software?  What
> does it say?
> 
> Bob
> 
>>>> -Original Message-
>>>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Mark
>>>> Spencer
>>>> Sent: Tuesday, September 01, 2015 12:54 PM
>>>> To: time-nuts@febo.com
>>>> Subject: [time-nuts] Z3805 service information ?
>>>> 
>>>> Hi, I realize this is a long shot but I'm curious if anyone has ever
> come across
>>>> any form of a service manual (or insight into a power on self test
> routine) for
>>>> the Z3805 gpsdo ?
>>>> 
>>>> One of mine is not working properly after being power cycled.   It works
> well
>>>> enough to blink the status lights on the front panel hence my request
> for info
>>>> about a possible power on self test routine.
>>>> 
>>>> I'll likely start by confirming the power supply voltages using another
> working
>>>> unit as a guide and then swap parts with another working unit but
> thought I
>>>> would look for service information first.
>>>> 
>>>> Thanks in advance for any help.
>>>> 
>>>> With the exception of two ocxo's that have a dedicated battery backup
>>>> system all my time nuts gear, computers, freezers, etc was power cycled
>>>> during a two day power outage after a wind storm while I was on
> vacation.   I
>>>> have a nice generator that sat un used in my garage (:
>>>> 
>>>> Mark Spencer
>>>> VE7AFZ
>>>> 
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[time-nuts] Z3805 service information ?

[Mark Spencer]

Hi, I realize this is a long shot but I'm curious if anyone has ever come 
across any form of a service manual (or insight into a power on self test 
routine) for the Z3805 gpsdo ?  

One of mine is not working properly after being power cycled.   It works well 
enough to blink the status lights on the front panel hence my request for info 
about a possible power on self test routine.

I'll likely start by confirming the power supply voltages using another working 
unit as a guide and then swap parts with another working unit but thought I 
would look for service information first.

Thanks in advance for any help. 

With the exception of two ocxo's that have a dedicated battery backup system 
all my time nuts gear, computers, freezers, etc was power cycled during a two 
day power outage after a wind storm while I was on vacation.   I have a nice 
generator that sat un used in my garage (:

Mark Spencer
VE7AFZ

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Re: [time-nuts] HP10811 vs 00105 OCXO

[Mark Spencer]

Hi Luciano.  That is interesting.  Thanks for sharing this.

I also have an HP105B with the old style oscillator.  (An auction site purchase 
from years ago.)   Yours seems at bit better than the one I have at tau's of 
approx 100 seconds or so.  I'm curious if you have any data for longer tau's ?


All the best Mark Spencer


 On Aug 6, 2015, at 8:37 PM, tim...@timeok.it wrote:
 
 
 here the ADEV of the two oscillator. I have added the Super performance of an 
 HP105B (old oscillator) bought in an Ham fest.
 
 Luciano
 
 
 
 On Fri 07/08/15 03:37 , Bob Camp kb...@n1k.org wrote:
 
 Hi
 
 HP 10811’s vary over almost a 100:1 range in terms of ADEV performance
 at short tau. The standard model is un-sealed so it has some issues
 with humidity when it is in storage for a long time. In both the case of
 the 10811 and the 105, their stability will improve as they are
 on power. In the case of long term storage, they both may continue to
 improve for more than a month.
 
 All of this makes any sort of comparison between the two models a bit
 difficult. About all you can say is that on a given day, this example of
 one
 was (or was not) more stable than that example of the other model.
 
 Bob
 
 On Aug 6, 2015, at 5:03 AM, tim...@timeok.it wrote:
 
 
 
 Hi,
 
 I have done some measurement comparing two HP OCXO, the HP10811 and the
 105.
 
 These two oscillator are mounted in the HP5065A rubidium Standard, the
 105 in the old models, the 10811 in newer, and for this purpose they are
 selected units.
 
 I have two HP5065A use the different oscillators. For the stability test
 I have set the two 5065A in Open loop so the OCXO are free running .
 I have done the measurements using as reference a third HP5065A in
 closed loop operation.
 
 Here the files show the frequency and phase difference.
 
 The 00105-6034 appear to be more stable as frequency than the 10811.
 
 comments?
 
 
 Luciano
 www.timeok.it [1]
 Message sent via Atmail Open -
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 and follow the instructions there.
 
 
 
 Links:
 --
 [1] http://webmail.timeok.it/parse.php?redirect=http://www.timeok.it
 [2]
 http://webmail.timeok.it/parse.php?redirect=http://atmail.org/%26lt%3BHP
 [3]
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[time-nuts] Bliley Crystal TC92 pinouts ?

[Mark Spencer]

Hi, I'm wondering if anyone has the pinouts or other info for a Bliley Crystal 
TC92 temperature stabilizer.   This is a unit about the size of a soup can with 
a 7 pin base.

The unit i have apparently contains a 100 kc crystal and it would be fun to 
fire this up and see if i can persuade the crystal to oscillate.  It looks to 
be 1950's to 1970's vintage.

Any info would be appreciated.   Yes I realize I can probably figure things out 
with an ohm meter (: but thought I would ask first.

All the best
Mark Spencer 

Sent from my iPad
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Re: [time-nuts] Splitters for the GPS antenna

[Mark Spencer]

The GPS splitter is spoken for.

Thanks
Mark Spencer

Sent from my iPhone

 On Jun 25, 2015, at 2:07 PM, Mark Spencer m...@alignedsolutions.com wrote:
 
 Sorry for the thread hi jack.   I also have a lightly used Symmetricom 58535A 
 dual port (one antenna, two receivers) gps splitter I would be happy to part 
 with.
 
 Please contact me off list of interested in this and perhaps we can come an 
 agreement.   It's fairly heavy so shipping may be pricey.
 
 Thanks
 Mark Spencer
 m...@alignedsolutions.com
 
 
 Sent from my iPhone
 
 On Jun 25, 2015, at 6:18 AM, Cash Olsen radio.kd5...@gmail.com wrote:
 
 I initially tried using Dishtv splitters with qualified success. On closer
 examination the bandpass between dish 1 and dish2 is different and neither
 actually calmed to pass the GPS frequencies. And indeed I had significantly
 different path losses.
 
 I wanted a better solution. I did a brief search and found the following.
 The results are much better and the price was very reasonable. My path
 losses appear to be balanced and generally agree within 1dB, with at least
 10 SV reporting 39 - 49dB. The splitter I tried has a claimed bandwidth of
 40 to 2400 MHz and a all ports power pass.
 
 Of course you have to have the adaptors from type N to type F and type F to
 type SMA. I was able to find all of those on Amazon and don't forget some
 type F terminators, they are hard to find in local box stores.
 
 Hope this helps some of the new guys, like myself, to get their labs up a
 little quicker.
 
 
 Computer Network Accessories, Inc.
 5520 Burkhardt Road
 Dayton, Ohio 45431
 Web: www.CNAweb.com http://www.cnaweb.com/
 Email: sa...@cnaweb.com
 Phone: 937-258-2708 - Fax: 937-258-2743
 
 
 Product NamePart No.QuantityItem PriceTotal Price4 Way 2GHz Splitter w/ DC
 Pass72-2443$4.10$12.30
 Subtotal:$12.30Shipping  Handling:$7.35Tax:$0.00
 --
 Order Total:$19.65
 
 -- 
 S. Cash Olsen KD5SSJ
 ARRL Technical Specialist
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Re: [time-nuts] Greetings from Australia

[Mark Spencer]

Hi Brek.   In my experience the perceived frequency difference from Doppler 
shift is of little or no relevance for amateur HF communications.   For 
amateurs involved in activities such as the frequency measurement test I 
believe it could be at times relevant at HF.  There might be a mode where 
Doppler shift is relevant for HF communications but I have never run across it.

In my experience when communicating at VHF and beyond it is helpful to have an 
accurate frequency standard when using modes such as CW, SSB, JT65 etc.

I routinely check the calibration of my 1.2 GHz (23 cm) SSB / CW setup each 
time I turn on the radio.   I use a GPSDO as a frequency source for this.  
Knowing the radio is on frequency gives me one less thing to worry about when 
trying to make 100 mile plus contacts on this band.  Even through the radio has 
a tcxo I still need to check the frequency each time I turn it on.

From time to time I also check the calibration of my lower frequency equipment 
as well.   The gear with TCXO's is usually close enough in frequency that I 
can use it on SSB and CW without having to worry about the difference between 
the dial frequency and the actual frequency.   

Radios that just have a plain crystal oscillator usually require me to figure 
out the difference between the dial frequency and the actual frequency when 
operating using SSB and CW at 144 MHz and higher.  

When using wider band modes such as FM on 144 and 440 MHz and narrow band modes 
below 30 MHz I usually trust that the dial frequency on the radio will be close 
enough.

I hope this was of some interest.

Best regards
Mark S
VE7AFZ

Sent from my iPhone

 On Jun 29, 2015, at 9:33 AM, Brek Martin bmar8...@bigpond.net.au wrote:
 
 Hi Guys :)
 I thought I’d say thanks for the add to the group and introduce myself.
 
 I’m only starting to get compulsive about time and frequency.
 My findings so far are that only the timing of the next second matters 
 because it’s too late
 to worry about the current second by the time you have the information about 
 it.
 It’s +10 hours here so I have to add 10 to everything, and that could 
 increment the date,
 so then a whole calendar program is required to know what the next date will 
 be,
 just because you need to know what date it will be on the next seconds tick 
 that occurs.
 
 I have a question…
 Is the reason most amateur radio people care about accurate frequency mostly 
 about
 operating at higher radio frequencies?
 I imagine if a bunch of radio enthusiasts aligned their HF radios with atomic 
 standards for use
 on those bands that doppler shift would ruin everything the additional 
 hardware put into it.
 Cheers, Brek.
 
 
 
 
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Re: [time-nuts] Jackson labs fury gpsdo with docxo for sale

[Mark Spencer]

Hi:

According to the brochure that price is for 20 plus pieces (presumably for the 
oem pcb module non docxo option variant although it does not say so.)

Best regards
Mark S

Sent from my iPhone

 On Jun 25, 2015, at 2:25 PM, Rhys D heyr...@gmail.com wrote:
 
 According to the brochure, they are only $750 new.
 
 Or am I missing something here?
 
 R
 
 On 26 June 2015 at 03:30, Mark Spencer m...@alignedsolutions.com wrote:
 
 Hi I'm wondering if there is any interest in my Jackson labs fury (desktop
 version) with the docxo option.   I purchased it new from Jackson Labs in
 2012.
 
 It has sat on a shelf powered up for almost the entire time I have owned
 it.  I've been very happy with the unit but I haven't made much use of it
 over the last year and don't foresee any future need for it.
 
 I'm not in a huge hurry to sell it but I would be looking for 1,250 USD
 plus insured shipping from Canada (also the buyer would need to pay any
 taxes or duties that are payable by the buyer.)  I would include the power
 supply it shipped with from Jackson labs.
 
 I'm also looking at selling it via some other channels as well so it may
 be gone soon.
 
 Please contact me off list if you are interested in pursuing this.   I'm
 happy to send photos and provide more details to an interested party.
 
 Thanks
 Mark Spencer
 m...@alignedsolutions.com
 
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[time-nuts] Jackson labs fury gpsdo with docxo for sale

[Mark Spencer]

Hi I'm wondering if there is any interest in my Jackson labs fury (desktop 
version) with the docxo option.   I purchased it new from Jackson Labs in 2012. 
 

It has sat on a shelf powered up for almost the entire time I have owned it.  
I've been very happy with the unit but I haven't made much use of it over the 
last year and don't foresee any future need for it.  

I'm not in a huge hurry to sell it but I would be looking for 1,250 USD plus 
insured shipping from Canada (also the buyer would need to pay any taxes or 
duties that are payable by the buyer.)  I would include the power supply it 
shipped with from Jackson labs.

I'm also looking at selling it via some other channels as well so it may be 
gone soon.

Please contact me off list if you are interested in pursuing this.   I'm happy 
to send photos and provide more details to an interested party.

Thanks 
Mark Spencer
m...@alignedsolutions.com

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Re: [time-nuts] Splitters for the GPS antenna

[Mark Spencer]

Sorry for the thread hi jack.   I also have a lightly used Symmetricom 58535A 
dual port (one antenna, two receivers) gps splitter I would be happy to part 
with.

Please contact me off list of interested in this and perhaps we can come an 
agreement.   It's fairly heavy so shipping may be pricey.

Thanks
Mark Spencer
m...@alignedsolutions.com


Sent from my iPhone

 On Jun 25, 2015, at 6:18 AM, Cash Olsen radio.kd5...@gmail.com wrote:
 
 I initially tried using Dishtv splitters with qualified success. On closer
 examination the bandpass between dish 1 and dish2 is different and neither
 actually calmed to pass the GPS frequencies. And indeed I had significantly
 different path losses.
 
 I wanted a better solution. I did a brief search and found the following.
 The results are much better and the price was very reasonable. My path
 losses appear to be balanced and generally agree within 1dB, with at least
 10 SV reporting 39 - 49dB. The splitter I tried has a claimed bandwidth of
 40 to 2400 MHz and a all ports power pass.
 
 Of course you have to have the adaptors from type N to type F and type F to
 type SMA. I was able to find all of those on Amazon and don't forget some
 type F terminators, they are hard to find in local box stores.
 
 Hope this helps some of the new guys, like myself, to get their labs up a
 little quicker.
 
 
 Computer Network Accessories, Inc.
 5520 Burkhardt Road
 Dayton, Ohio 45431
 Web: www.CNAweb.com http://www.cnaweb.com/
 Email: sa...@cnaweb.com
 Phone: 937-258-2708 - Fax: 937-258-2743
 
 
 Product NamePart No.QuantityItem PriceTotal Price4 Way 2GHz Splitter w/ DC
 Pass72-2443$4.10$12.30
 Subtotal:$12.30Shipping  Handling:$7.35Tax:$0.00
 --
 Order Total:$19.65
 
 -- 
 S. Cash Olsen KD5SSJ
 ARRL Technical Specialist
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Re: [time-nuts] Small time server for mobile use.

[Mark Spencer]

Thanks for this.   This (and the other responses) were the type of answers I 
was hoping for.

The budget is probably up to several thousand for a robust COTS product that 
won't add significant operational hassles.   (Kludging a laptop to run as an 
NTP server would be an example of a solution that would add operational 
hassles.)  Equipment designed for rack mounting is a bit less than ideal (the 
equipment bay in the vehicle is not really set up for rack mounted gear) but we 
could probably work out a way to mount a one u device, and mounting a laptop 
adds it's own set of challenges, although a laptop can be mounted outside of 
the equipment bay.   The ideal form factor would be something the size of a 
small paper back book (or smaller) that could be surface mounted or secured via 
clamps to a piece of tubing that is already in the equipment bay.



Sent from my iPad

On 2015-05-12, at 3:03 PM, Bob Darlington rdarling...@gmail.com wrote:

 What's your budget?  I've done this with 1U sized NTP servers from
 Symmetricom (S300 and S350 systems) for mobile military use.  These are a
 few thousand bucks a pop.  They're rugged, and held up just fine in places
 the military goes.Compared to the rest of the system I was working on, this
 was quite small in comparison and we used more than one at each location.
 My personal one died recently so I'm working on developing a cape for the
 BeagleBone Black.  The prototype is working just fine so far so I'm moving
 forward with a board layout and eventual sale to the list members if there
 is any interest (I'm not asking for interest yet).
 
 -Bob
 
 On Tue, May 12, 2015 at 11:11 AM, Mark Spencer m...@alignedsolutions.com
 wrote:
 
 Hi sorry for a possibly OT post.
 Has anyone had practical experience with small commercially available time
 servers / ntp servers suitable for mobile  use in a vehicle.
 
 The use case is I am in need of an accurate (ie.  within 100 ms) time
 source for several pc's in moving vehicle.Being able to run directly
 off a 13.8 or 28 VDC  source would be a major plus but AC power is also
 available.
 
 Hold over if there are gaps in GPS coverage is also a major plus.
 
 We already have a GPS with a 1 pps output, but an integrated box with it's
 own GPS would be best.
 
 Yes I am aware I could feed a 1 pps signal into a laptop and use that as a
 time server and I may end up going that route.
 
 There is a small Ethernet LAN in the vehicle.  The pc's currently get
 their time via a wireless connection to various NTP servers.   I need to be
 able to ensure accurate time on the PC's if there is no wireless coverage.
 
 
 This is for a one off project so piecing together various parts is an
 option but a single box COTS solution would be nice.  I've found a few
 candidates via web searches but would welcome any feed back.
 
 Thanks in advance
 
 Mark Spencer
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Re: [time-nuts] Small time server for mobile use.

[Mark Spencer]

Thanks.   Yep running an extra Dc to Dc converter is an option but we already 
have access to clean 28 and 13.8 VDC supplies with some extra capacity.  We 
could likely provide up to a 100 watts of power for this system (I doubt it 
would need that much.)

The hold over requirement is in the range of several hours.   The temperature 
swings could be fairly large (ie. cold soak outside at minus 35C, then inside a 
heated garage, plus what ever temperature the equipment bay rises to when the 
vehicle has been operating for some time probably less than 85 deg C.) mounting 
the equipment in locations other than the equipment bay would likely result in 
lower max temperatures.

I'm not sure about the cooling capacity of the equipment bay, but there are 
other areas with climate control systems where this device could be installed 
if needed.  I'm fairly comfortable that a device that generated up to 100 watts 
of heat could be accommodated (ie, I would assume all of the electrical power 
going into the device gets turned into heat) but would need to double check 
this.

The size is somewhat flexible.

To a certain extent the requirements could be adjusted to fit an existing COTS 
product that was perceived as generally suited to the application.   As this is 
a one off requirement, that will be in use for a limited time some limitations 
can be worked around or lived with.

The budget could be several thousand dollars.

I thought about a Raspberry Pi type of solution, but need to factor in the cost 
of my time or that of someone else, plus there is a strong desire to either 
drop in a COTS black box or use a laptop.

Thanks for the comments.


Sent from my iPad

On 2015-05-12, at 3:54 PM, Pete Stephenson p...@heypete.com wrote:

 On Tue, May 12, 2015 at 7:11 PM, Mark Spencer m...@alignedsolutions.com 
 wrote:
 Hi sorry for a possibly OT post.
 Has anyone had practical experience with small commercially available time 
 servers / ntp servers suitable for mobile  use in a vehicle.
 
 I don't know about any commercially-available products, but it sounds
 like it'd be pretty straightforward to do with a Raspberry Pi or
 something similar if you don't mind a little bit of DIY.
 
 What constraints do you have on budget, size, power requirements, and cooling?
 
 The use case is I am in need of an accurate (ie.  within 100 ms) time source 
 for several pc's in moving vehicle.Being able to run directly off a 13.8 
 or 28 VDC  source would be a major plus but AC power is also available.
 
 The Pi runs on 5V DC. DC-DC buck converters that can convert 7-35V to
 5V DC are cheap, efficient, and widely available. Shouldn't be a
 problem.
 
 Hold over if there are gaps in GPS coverage is also a major plus.
 
 How long would you need holdover? Seconds or minutes (e.g. driving
 through a tunnel)? Hours? Days? Would the computers in the vehicle be
 subject to large temperature shifts?
 
 A Pi should be able to handle +/- 100ms of holdover in the
 minutes-to-hours range using NTP.
 
 We already have a GPS with a 1 pps output, but an integrated box with it's 
 own GPS would be best.
 
 A tiny integrated module like the Adafruit Ultimate GPS breakout[1] is
 cheap, handy, and emits a 1PPS signal. It's also extremely small and
 can be purchased in hat form[2] that mounts directly to the Pi.
 
 Cheers!
 -Pete
 
 [1] https://www.adafruit.com/products/746
 [2] https://www.adafruit.com/products/2324
 
 -- 
 Pete Stephenson
 
 On Tue, May 12, 2015 at 7:11 PM, Mark Spencer m...@alignedsolutions.com 
 wrote:
 Hi sorry for a possibly OT post.
 Has anyone had practical experience with small commercially available time 
 servers / ntp servers suitable for mobile  use in a vehicle.
 
 The use case is I am in need of an accurate (ie.  within 100 ms) time source 
 for several pc's in moving vehicle.Being able to run directly off a 13.8 
 or 28 VDC  source would be a major plus but AC power is also available.
 
 Hold over if there are gaps in GPS coverage is also a major plus.
 
 We already have a GPS with a 1 pps output, but an integrated box with it's 
 own GPS would be best.
 
 Yes I am aware I could feed a 1 pps signal into a laptop and use that as a 
 time server and I may end up going that route.
 
 There is a small Ethernet LAN in the vehicle.  The pc's currently get their 
 time via a wireless connection to various NTP servers.   I need to be able 
 to ensure accurate time on the PC's if there is no wireless coverage.
 
 
 This is for a one off project so piecing together various parts is an option 
 but a single box COTS solution would be nice.  I've found a few candidates 
 via web searches but would welcome any feed back.
 
 Thanks in advance
 
 Mark Spencer
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 and follow the instructions there.
 
 
 
 -- 
 Pete Stephenson

Re: [time-nuts] Time in a cave

[Mark Spencer]

Hi a few questions, 

Does your cave have any connectivity to the outside world ?

Are there any places your cave has connectivity to that might have enough of a 
sky view to provide periodic gps coverage ?

Do you need a COTS (commercial off the shelf) solution or can you accept 
something that has been kludged together ?

Do you need a Peng or other professional to sign off on the solution ?

(In my experience PTP may on occasion be found in industrial settings where a 
Peng may be required to sign off on the solution.)

Mark Spencer

On 2015-05-12, at 4:00 PM, Tucek, Joseph joseph.tu...@hp.com wrote:

 I'm looking for information on non-GPS time sources.
 
 For background, I need to provide PTP to a cluster where we don't have line 
 of sight to the sky, and are unlikely to get roof-rights without a fight.  
 There are CDMA solutions that would work (e.g. Endrun Technologies), but I 
 was wondering if there were any other options.  I either need an indoor 
 capable PTP, or an indoor capable PPS.  Microsemi claims to have an indoor 
 capable GNSS system, but I've yet to find a sales rep to talk about it; if 
 anyone has a link to one who can, I'd love to find out the problems^W^W^W^W 
 talk to them about it.
 
 For an example of something that almost but doesn't quite work, Beagle 
 Software has a CDMA NTP server, but they do neither PTP nor PPS in the CDMA 
 version.  Similarly, Meinberg will sell a PTP unit that freeruns (if you 
 override the config), but they have no solution to discipline via CDMA.
 
 I'm also curious if anyone has any idea about non-GPS time sync after CDMA 
 gets turned off (can I get time from 4G?).
 
 My endgame worst case is to just do PPS from a stratum 2 NTP (or even a 
 freerunning oscillator) and lie to my PTP server; hard sync to UTC is a 
 secondary concern so long as the cluster agrees with itself.  Endrun is 
 looking pretty good, but I'd really like to have a second option to compare 
 against.
 
 -Joe
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[time-nuts] Small time server for mobile use.

[Mark Spencer]

Hi sorry for a possibly OT post.   
Has anyone had practical experience with small commercially available time 
servers / ntp servers suitable for mobile  use in a vehicle.  

 The use case is I am in need of an accurate (ie.  within 100 ms) time source 
for several pc's in moving vehicle.Being able to run directly off a 13.8 or 
28 VDC  source would be a major plus but AC power is also available.

Hold over if there are gaps in GPS coverage is also a major plus.

We already have a GPS with a 1 pps output, but an integrated box with it's own 
GPS would be best.

Yes I am aware I could feed a 1 pps signal into a laptop and use that as a time 
server and I may end up going that route.

There is a small Ethernet LAN in the vehicle.  The pc's currently get their 
time via a wireless connection to various NTP servers.   I need to be able to 
ensure accurate time on the PC's if there is no wireless coverage.


This is for a one off project so piecing together various parts is an option 
but a single box COTS solution would be nice.  I've found a few candidates via 
web searches but would welcome any feed back.

Thanks in advance

Mark Spencer
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Re: [time-nuts] lawnmower robots may be the end of VLF timekeeping

[Mark Spencer]

In practice it seems to be hard to fight interference issues at lower 
frequencies.   A local 50,000 watt AM (medium wave) broadcaster, put up a FM 
(VHF) transmitter several years ago.   One of the reasons they gave for going 
to FM were the interference issues on the AM band.   I noticed the newer 
electric trolly busses were significant sources of interference on my drive 
home from work. 

I've largely stopped using my HF amateur radios in the city, and even at VHF 
the noise floor is noticeably lower in the country side.

Reception for my WWVB clock is also rather hit or miss from south western 
Canada but it does work on occasion.I was however pleased that my 1.2 Ghz 
amateur radio activities don't seem to disrupt my own GPS reception despite 
less 15 feet of antenna separation. 

Sent from my iPad

On 2015-05-09, at 12:48 PM, Bob Camp kb...@n1k.org wrote:

 Hi
 
 The real questions:
 
 1) Are they breaking any laws with their pollution? 
 
 2) Is there a regulatory body that is charged with enforcing those laws?
 
 3) Is the cost (hours / dollars / hassle) of taking action prohibitive? 
 
 Often it’s a combination of more than one that gets you …
 
 This is fundamentally no different than the boys setting up their system 
 right next to
 GPS. The main difference is that they had to go through the licensing process 
 and not
 all these devices do that. I do know that when every radio clock within 1/2 
 Km goes dead,
 there are towns that will have a lot of people scratching their heads ….
 
 Bob
 
 On May 9, 2015, at 2:15 PM, Björn b...@lysator.liu.se wrote:
 
 The same has been observed by the lightning listeners at blitzortnung.org
 
 --  
 
 Björn
 
 div Originalmeddelande /divdivFrån: Poul-Henning Kamp 
 p...@phk.freebsd.dk /divdivDatum:2015-05-09  14:15  (GMT+01:00) 
 /divdivTill: time-nuts@febo.com /divdivRubrik: [time-nuts] lawnmower 
 robots may be the end of VLF timekeeping /divdiv
 /divI spent some time capturing some data today.
 
 The measurements is from my $20 loop-antenna in the attic, which is
 something like 8 meters up and 10 meters besides the lawn-mower loop:
 
 http://phk.freebsd.dk/time/20150509.html
 
 -- 
 Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
 p...@freebsd.org | TCP/IP since RFC 956
 FreeBSD committer   | BSD since 4.3-tahoe
 Never attribute to malice what can adequately be explained by incompetence.
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Re: [time-nuts] Tymserve 2100 thinks it's 1995?

[Mark Spencer]

Hi, by any chance do your Tymserve 2100's havea 1pps input that they can use to 
receive a timing source in lieuof their own GPS once the date and time are set 
manually? I run my Datum badged Tymserve 2000 this way and other thanhaving to 
manually deal with leap seconds it has been working well sofar. (Prior posts 
have indicated that at least one of the users havingtroubles with their 
Tymserve 2100 has access to another GPS, and also indicatedthat the units would 
keep the correct date in free mode, so perhaps they couldbe clocked from an 
external GPS.)
Essentially I use my Tymserve 2000 as a NTP serverthat is clocked by an 
external 1pps source from a GPSDO. I have no ideahow long it will keep running 
properly, but for a home lab it meets my needs. I wouldn't want to use this 
approach at work or for a critical applicationbut thought I would offer this a 
suggestion as a possible way to breathe a bitmore life into an older piece of 
equipment.
Regards
Mark Spencer




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Re: [time-nuts] HP5328A HP5328B option 040

[Mark Spencer]

If anyone has a burning desire for a HP5328 with a volt meter module (and a 
GPIB board) please contact me off list.

Regards
Mark Spencer

Sent from my iPad

On 2015-04-23, at 3:18 PM, Bob Albert via time-nuts time-nuts@febo.com wrote:

 From your comments, it seems that finding a voltmeter board to add to my 
 5328A isn't worth the trouble.  I have been looking for one even though I 
 have plenty of voltmeters.  I assume the option allows measurement of the 
 signal inputs but still probably isn't worth all the agony of changing the 
 panel, etc.
 
 Am I making sense?
 Bob K6DDX 
 
 
 On Thursday, April 23, 2015 12:48 PM, Richard (Rick) Karlquist 
 rich...@karlquist.com wrote:
 
 
 On 4/23/2015 12:20 AM, VK2DAP wrote:
 Dear time-nuts,
 
 I have a question about the HP5328A and HP5328B universal counters.
 
 1) Generally speaking, would it be correct to say that when a product model 
 number changes from A to B, that represents an improvement or major update 
 to a product?
 
 2) I am interested in the delay option that is mentioned in the user 
 manual for the HP5328A (option 040). My question is simple. Why does this 
 option not feature in the HP5328B, but only as option 040 on the HP5328A?
 
 
 
 Now you have asked a very interesting question.  Since you
 are new to time-nuts, you probably don't know I worked
 for HP/Agilent/Keysight for 35 years.  It would be
 a gross oversimplification to assume that an A/B change
 is an improvement, although in some cases that may
 be true.  Often it has more to do with certain parts
 becoming unavailable.  You should also know that there
 is typically a 5 year support life after the product
 goes out of production.  It is very common that they
 will increment the suffix to get the 5 year clock
 running so they no longer have to support very old
 instruments.  This was certainly the case with the
 5061B cesium standard.  The nixie displays were
 unobtainium and we couldn't support the 5061A because
 of this.  I don't know specifically about the 5328A
 vs B.  However, I was the project manager for the
 5334B counter.  The way that came about was that I
 just happened to notice that there were various design
 aspects of the 5334A that wasted a lot of money.  I
 didn't work in the counters section at the time, but
 nevertheless I annoyed the RD manager by pointing
 out these money leaks.  I guess he got tired of hearing
 me complain and one day he offered my the job of project
 manager on a 5334B model.  We needed to reduce cost
 because we were losing military contracts to Racal-Dana.
 I changed certain design details in the B model where
 I could save money.  The idea was to simply keep the
 performance the same and not add features.  There were
 many things I inherited from the A model that I left
 alone if I couldn't reduce the cost.  We were also on
 a very tight schedule.  This prevented me from replacing
 the 4 separate microprocessors in the 34A with a single
 one.  (Very long story as to why this was)
 
 Now to get to your question about why a feature in the
 A version would not carry through to the B version.
 The 5334A had an option of a digital voltmeter, which was
 put in essentially because we could, but then justified
 after the fact by claiming that customers wanted it
 because some of them ordered the option.  I never thought
 this made sense and used my authority as 5334B project manager
 to get rid of it in the 5334B.  Since HP also sold
 voltmeters, they could always buy a voltmeter from
 our voltmeter division.  There are a bunch of reasons
 why the 5328B would lose a feature that the 5328A had,
 but the point is that this doesn't break any rule.
 
 Rick Karlquist N6RK
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Re: [time-nuts] June 30 2015 leap second

[Mark Spencer]

I've often wondered why more systems don't use TAI or other similar time scales 
as their time source.   If needed the time displayed to end users or third 
parties could be converted to UTC just prior to presentation or transmittal.

For example a financial system that needs to time stamp individual transactions 
could sync their system clocks to TAI.   As the difference between TAI and UTC 
changed (or was scheduled to change) a lookup table could be updated that would 
provide the offset between UTC and TAI for given date ranges.

Sent from my iPad

On 2015-01-10, at 7:49 AM, Jim Lux jim...@earthlink.net wrote:

 On 1/9/15 4:57 PM, Henry Hallam wrote:
 Such slewing solutions are OK for Google.  They wouldn't work well for
 one of the systems I work with, which uses system time to calculate
 the position of a LEO satellite for purpose of pointing a 7.6 meter
 X-band dish.  Half a second of error corresponds to a pointing error
 of 0.5 degrees, well outside the main lobe of the antenna beam.
 
 
 Which is why we use TAI in the space business and don't fool with this 
 Greenwich Mean Time or Coordinated Universal Time which is discontinuous 
 and potentially non-monotonic.
 
 We DO need to compensate for the earth's varying rotational speed, though, 
 but that's just handled as a separate model for deep space, or for LEO, where 
 the coordinate system is Earth Centered, absorbed into the spacecraft orbital 
 elements.. nobody is going to use 1 year old ephemerides)
 
 
 I do find myself explaining exactly WHY we can't just use PC system time, 
 etc. and periodic leap seconds are an object lesson in why not.
 
 (or, you can arrange to not being doing any operations at the moment of 
 leap...that's been done too)
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[time-nuts] Does adjusting ocxo's degrade adev / madev ?

[Mark Spencer]

I've long had a nagging suspicion that OCXO's that are not adjusted will in 
practice have lower ADEV than ones that are tweaked regularly.   Several days 
ago I noticed that one of my 10811's was performing quite well (I believe this 
is the first time any of 10811's have delivered adev / madev numbers in the 
13's) and this was sustained for approx 2 days.   After trimming the frequency 
and letting it sit for a number of hours  I noticed the adev was notably worse. 

I realize there could be a mechanical issue with the trimmer inside the ocxo 
that is causing this or simply touching the ocxo while adjusting it may have 
also caused this, but is changing the frequency of an OCXO in of it self likely 
to have an affect on ADEV / MADEV after a few hours ?

Looking at the linear residual plot of the phase difference between the 10811 
and the reference, I see a fairly large difference at first, then a somewhat 
smaller change, then a series of smaller changes.  But I may be reading to much 
into this plot.

I don't expect an absolute answer to this but I'm curious if anyone else has 
seen this.


Sent from my iPad
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Re: [time-nuts] 10 MHz Filters

[Mark Spencer]

Yep.   I found a lot of RF related issues appeared to go away when I switched 
to double shielded cables, stopped using T connectors for distributing signals, 
purchased and used HP distribution amps, terminated un used ports with 50 ohm 
loads etc.

I also found ferrite cores applied on the outside of longer cables to be 
helpful as well.  (I found it was useful to measure the actual currents flowing 
in the cable shields before and after adding the ferrite cores.)

I still have a couple of issues that occur when I occasionally transmit at the 
300 watt level on VHF but the day to day issues where by WWV on 5 and 10 Mhz 
was hard to hear at times due to signal leakage and many low power 
transmissions could be counted on to influence a time lab frequency plot are 
gone now.

I expect issues are still there but they are below the detection threshold for 
me.  My time nuts gear and radio gear are separate but still in the same house.

Mark Spencer

On 2014-11-27, at 1:47 PM, Bob Camp kb...@n1k.org wrote:

 Hi
 
 You can also discover interesting things about the transformer it’s self in 
 some circuits. They do what they do, but they also bring along a new set of 
 issues. Sometimes simpler is better. If you don’t *need* what the transformer 
 does, why add more complications ? 
 
 If you don’t lift the ground, the transformer isn’t doing much for you 
 isolation wise.
 
 If you do lift the ground, you need a lot more than just the transformer to 
 make it all work and isolate properly. Once you add all that “stuff” you 
 don’t have a simple circuit anymore.
 
 ——
 
 One example:
 
 The most likely “threat” to your distribution system is a cell or portable 
 phone. The beast fires up at random times and spews RF around everywhere. 
 That’s the signal you want to isolate and shield against. It’s at some 
 frequency between 40 MHz and 6 GHz depending on what it is. What ever you do 
 needs to work over that range for isolation / shielding. It also needs to 
 pass 10 MHz. Don’t have a phone in sight? How about WiFi, Bluetooth, and RF 
 based remote controls ….
 
 Why is it a threat? The RF comes back into your amp and changes bias levels / 
 inter modulates with the 10 MHz. Either way, your 10 MHz moves around a bit. 
 Is this purely theoretical? Nope, it happens far more often than you’d think. 
 I’ve seen it a number of times. 
 
 A simple transformer at 10 MHz is not going to retain balance and isolation 
 over 40MHz to 6 GHz. Even if it could the coax connector will imbalance it 
 pretty badly. No balance = no isolation. 
 
 ---
 
 Good cables and a passive splitter have their issues, so do logic gates. Both 
 have their advantages. More complicated is not always better. 
 
 23 dBm out of a KS box going down to +7 out gives you 16 db of room for 
 attenuation. At 3 db for each 2:1 split, that’s 2^5 splits. It’s rare to find 
 a need for 32 outputs. You can get 8 outputs at +13 dbm. That’s pretty hot 
 for a distribution amp output.
 
 Bob
 
 
 On Nov 27, 2014, at 2:02 PM, John Miles j...@miles.io wrote:
 
 For the most part, you don't want transformer isolation unless you plan on 
 using balanced lines.  There are worse things than ground loops out there, 
 and lifting a coax shield away from ground is a great way to find all of 
 them.
 
 You definitely don't want 10.7 MHz IF transformers, unless you are just 
 trying to build a thermometer.
 
 -- john, KE5FX
 Miles Design LLC
 
 -Original Message-
 From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Perry
 Sandeen via time-nuts
 Sent: Wednesday, November 26, 2014 8:08 PM
 To: time-nuts
 Subject: [time-nuts] 10 MHz Filters
 
 List,
 
 
 
 I have seen on the net a 10 MHz filter using 10.7 IFtransformers but have no
 idea how well they would work for isolation with thenew style Lucent boxes.
 
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Re: [time-nuts] lightening protection of a GPSDO system / optical isolated distribution amp

[Mark Spencer]

Sweet.   I settled on #3 copper for my antenna grounding system on economic 
grounds and had a debate with a residential electrical contractor about 
bonding the antenna ground to the electrical service ground.   The city 
inspector passed the system with the bond installed.

I haven't used poly phasers but do hope to at least stop the house from burning 
down in the event of a lightning strike on the roof mounted antennas.   

I also found that the metallic city water supply pipe is by far the best ground 
I have (at least for 60 cycle AC.) (Using a clamp on meter I can measure an 
appreciable current thru it, unlike the other two grounds.   I presume the 
current is being diverted from the utility neutral and is eventually making 
it's way back to the transformer that powers my house.) I'm glad the water pipe 
is also bonded to the electrical service ground.   I'm happy that I don't have 
any appreciable currents flowing thru my antenna ground.This might be 
something to carefully consider (or possibly have looked at by a pro) if you 
have a really low impedance ground.   I've heard anecdotal accounts of sparks 
occurring when low impedance antenna grounds are connected to an electrical 
service ground.

My usual disclaimer of I'm not an expert in this field, the preceding is only 
my opinion,  and don't rely on this applies.

Mark Spencer

On 2014-11-26, at 2:56 PM, Martin A Flynn mafl...@theflynn.org wrote:

 On 11/26/2014 5:14 PM, Jim Lux wrote:
 On 11/26/14, 2:00 PM, Martin A Flynn wrote:
 The N2MO station has an external GPS antenna on the gable end of the
 building.  It's connected to the polyphaser arrestor with FSJ4-50
 superflex.
 
 The antenna mounting pipe has a #2 ground wire  (33.6 mm/2)  the
 polyphaser has it's own #2 ground wire.  Both connect to an 8' x 5/8
 (2.4m x 16mm) driven ground rod.  The jacket of the superflex is
 grounded with the factoryt Andrew kit as well
 
 Even with the GPS antenna lower in elevation then the HF beam and other
 antenna (with similar protection)  I have concerns about leaving it
 connected all the time.
 AWG #2 seems a tad overkill, the current in a stroke can be carried by AWG 
 #10 without melting, but maybe you had a lot of it around for other reasons. 
  I suspect the coax shield has smaller cross sectional area than AWG #2 and 
 you'll protect your grounding wire by blowing up the coaxgrin. (in fact, 
 looking at the data sheet for FSJ4-50, the DC resistance of the outer 
 conductor is 1 ohm/1000 ft = AWG 10.. it's actually more resistance than the 
 inner conductor (the inner conductor is 0.820ohms/kft, and 0.140 inch in 
 diameter, compare to AWG 10 which is very close to 0.100 inch in diameter).
 
 Hopefully your driven ground rod is bonded to the other system grounds?
 
 I'd worry about multipath from the HF beam and tower (although maybe you're 
 not using that GPS for time-nuts 1E-20 precision...grin)
 The #2 copper was recycled.   The main RF grounding trapeze is tied to the 
 grounding electrode system with 1/0, which was also recycled from another 
 project.
 
 Re the time-nuttery:  Only 1E-14.  Can't afford better (yet).
 
 
 
 
 
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Re: [time-nuts] lightening protection of a GPSDO system / optical isolated distribution amp

[Mark Spencer]

In my opinion,

I'd be inclined to find a way to run a suitable wire around the building.I 
don't think you want your interior electrical wiring serving as the only bond 
between two different grounds if energy from a lightning strike flows thru your 
antenna feed line and then thru your time nuts gear that probably has a path to 
the other ground thru the wiring in the building.

Other fault conditions that cause significant currents to flow thru your ground 
system could also cause issues if the only bond between the two ground systems 
is thru your house wiring and time nuts gear.

Disclaimer I'm not an electrical engineer or lightning protection expert so 
please don't rely on this comment.



Mark Spencer

On 2014-11-26, at 2:54 PM, Hal Murray hmur...@megapathdsl.net wrote:

 
 albertson.ch...@gmail.com said:
 The ground rod needs to be bonded to the rest of the building ground system.
 
 How do I do that effectively if the power goes in the front of the building 
 and the antenna is on the back?
 
 
 
 -- 
 These are my opinions.  I hate spam.
 
 
 
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Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812...

[Mark Spencer]

One of my Z3805's (with the double oven 10811 ocxo iirc) also performs 
similarly at times to the 58503A mentioned by Said.   From an adev perspective 
it's close to my BVA at some tau's (around a hundred seconds or so iirc.)  At 
times though the output seems to jump in frequency.   My other Z3805 from the 
same source doesn't work as well.

None of the 10811's in my various pieces of test gear (some of which I 
basically purchased to get the 10811's) worked all that well from an Adev 
perspective.  I used to buy HP5328 counters on the usual auction site with 
10811's and the 500MHz C channel for quite low prices.At least I still have 
a nice collection of frequency counters.


Sent from my iPad

On 2014-11-17, at 1:23 PM, Said Jackson via time-nuts time-nuts@febo.com 
wrote:

 Correct on all counts Bob.
 
 My two 58503A units from China are great for both ADEV and PN measurements, 
 better than anything else I have as a combo (I have Wenzel ULNs for even 
 lower PN testing but they don't have any usable ADEV).  I also have a costly 
 BVA and it can't compete against the HP unit.
 
 Those 10811s just rule.
 
 In fact my only complaint about the 58503A are the 60Hz related small spurs 
 you can see in the plots...
 
 Bye,
 Said
 
 Sent From iPhone
 
 On Nov 17, 2014, at 12:28, Bob Camp kb...@n1k.org wrote:
 
 Hi
 
 The 58503 is a Z3801 with a pretty instrument style package put around it - 
 right?
 
 If so, it might / should  have a 10811 in it rather than an MTI OCXO. The 
 10811 is rated for -155 dbc at 100 Hz. That is much better than the noise 
 floor that the MTI’s seem to produce at 100 Hz. About the only other GPSDO 
 OCXO that gets to that level is the one in the original TBolts . There you 
 very much have to deal with spurs. That make the noise floor of limited use 
 in a practical system. 
 
 Bob
 
 On Nov 17, 2014, at 2:26 PM, saidj...@aol.com wrote:
 
 Hi Bob,
 
 yes, the 10MHz plot is rotten, no doubt. The 15MHz plot is quite good till 
 about 40Hz offset, then it becomes pretty rotten too.
 
 Here is one of my 58503A units (using the 10811 OCXO) as a comparison.. 
 measured against our DROR-IIA (this plot was actually done to show the 
 DROR-IIA PN, but since that unit actually has less noise and spurs than the 
 58503A we can simply use it as the reference for this purpose).
 
 The good news is that getting the close-in phase noise to be good is very 
 hard to do and the unit delivers that out-of-the box already. Filtering out 
 the noise and spurs above 40Hz offset is pretty easy to do. It should be 
 fairly straight forward to cobble up a small PN filter for those units to 
 get rid of the noise and spurs above 40Hz offset.
 
 bye,
 Said
 
 In a message dated 11/17/2014 09:31:46 Pacific Standard Time, kb...@n1k.org 
 writes:
 Hi
 
 Here’s the phase noise on the 15 MHz. There are a few spurs, and an very 
 real hump out at the likely frequency of the Lucent switcher.  The 15 MHz 
 is pretty clean compared to most /all of the other units I’ve seen on the 
 surplus market. 
 
 I would not multiply this up to 40 GHz with a broadband multiplier. I would 
 be quite happy to run it into a PLL with a rational bandwidth. You will 
 beat the noise on the output with a fairly simple VHF VCXO past 100 Hz. No 
 reason to have a bandwidth outside the 20 to 80 Hz range. 
 
 Math:
 
 15 MHz to 150 MHz - 20 log (N) - 20 db.
 
 -140 dbc / Hz shown below at 100 Hz offset - -120 dbc/Hz
 
 You can get numbers better than -120 dbc/Hz at 100 Hz offset out of a 
 number of pretty simple VHF VCXO circuits. Bert has one that seems to work 
 fine for him. 
 
 Bob
 
 DROR-IIA_Phase_Noise.png
 
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Re: [time-nuts] 10 MHz OCXO recommendations

[Mark Spencer]

Sorry a few more points to mention.

If for some reason I am particularly concerned about the stability of an OCXO 
reference I will compare it to another OCXO and on occasion to a GPSDO as well 
while measuring a Device Under Test.  This gives me some comfort that if am 
looking at the performance of a particular Device Under Test that any drift 
in the OCXO I am using as a reference would have been detected.   (It also 
gives me a reason to keep my stack of HP5370 and HP5335 counters running.) I 
don't expect this approach to give me absolute certainty of picking up drift or 
jumps in my reference but it does give me some comfort.

While I suspect this approach would not go over very well in a commercial lab 
vs buying a high performance cesium standard or H Maser (:  for hobby use it 
seems to work for me.   Timelab is also useful for collecting analyzing the 
data from the various counters.  I also trigger all the counters from the same 
1pps source.

I typically compare my best OCXO's to my best GPSDO on a more or less 
continuous basis (from a time nuts perspective it's of some interest to look at 
their long term drift.)  From time to time I also cross check my best GPSDO 
against another GPSDO (:

Regards Mark Spencer

Sent from my iPad

On 2014-11-11, at 4:26 PM, Charles Steinmetz csteinm...@yandex.com wrote:

 Mark wrote:
 
 I find the concept of occasionally adjusting a good OCXO  which in turn is 
 used as a reference works well for me.I have some that haven't needed 
 adjustment for over 2 years (they are still well within one part per billion 
 of being on frequency.)
 
 A few of us have advocated this approach on the list, and there is good 
 reason for it.  A GPSDO offers two advantages: (1) it is self-adjusting, 
 therefore easy to own and use; and (2) it has better stability at long tau 
 than the OCXO alone.  The price you pay for those advantages is poorer 
 stability at low tau than the OCXO alone, which can be anywhere from slight 
 with a good design (e.g., Thunderbolt, Z3801) to shockingly bad with a bad 
 design (including many DIY attempts).
 
 If one does not need the very best performance at long tau -- and most 
 time-nuts do not -- a free-running OCXO that you adjust manually every now 
 and then can be the best reference available to the average time nut.  (Long 
 tau can be anywhere from 100 seconds to several thousand seconds, depending 
 on the particular OCXO.)  Plus, not spending money on GPS discipline allows 
 you to spend more on the OCXO to get better stability at low tau, and a more 
 extended upper limit on low tau (say, better than GPS all the way to 2000 
 seconds instead of 200 seconds).
 
 Personally, I do use GPS discipline to keep my best OCXO in perpetual 
 adjustment, but that is mostly for convenience.  Usually, I turn 
 disciplining off when I'm taking data.  Only when I'm doing something where 
 the data are averaged for longer than about 3000 seconds do I leave it on 
 (3000 seconds is based on the stability of my particular OCXO).
 
 Remember, GPS has a well-defined stability floor, and is not better than a 
 good OCXO at averaging times (tau) less than 100 or even 1000 seconds -- so 
 GPS discipline cannot do anything to help the stability of a good OCXO at 
 shorter tau than that.  (Yes, it may be able to help a lousy OCXO or TCXO at 
 lower tau -- but you can get a better OCXO than that for $20, so why bother?) 
  There is so much focus on GPSDOs that I think many time nuts do not realize 
 this fundamental fact.
 
 A few rules of thumb:
 
 --  An OCXO is the best low-tau reference most amateurs can afford
 --  GPS discipline cannot help at low tau because it is noisy
 --  Most of us do not need extreme stability at long tau
 
 And some general conclusions:
 
 --  Get the best OCXO you can find
 --  Enclose it (thermally isolated from the enclosure)
 --  Don't try to whip a so-so OCXO into shape with GPS discipline
 
 Finding a really good OCXO may take some effort.  Some models are more likely 
 to be really good than others (like the BVA that Mark mentioned, and some 
 others that have been vetted in large numbers), but even then there can be 
 large differences from sample to sample.  So, one may need to sort through a 
 number of them to find a really good one.  If one doesn't have access to a 
 clearly better oscillator for comparison, using the three-cornered hat 
 technique with one's best oscillators is probably the best method available 
 to the amateur time nut.  Note that quartz oscillators tend to exhibit best 
 stability if they are left on continuously, and stability may improve for a 
 long time (months, perhaps even many months) after they are turned on, 
 depending on how long they were off and how much trauma they received before 
 being powered up again).
 
 The point is that GPS discipline is not always (and maybe, not usually) the 
 best way to get the best stability possibile over the range of tau that is 
 most important

Re: [time-nuts] 10 MHz OCXO recommendations

[Mark Spencer]

Hi I have not had much luck with ocxo's sourced from the usual auction site.   

By far and away the best value for money for me has been found in some packaged 
frequency standards containing OCXO's and a non auction site purchase of a 
BVA OCXO.  

I find the concept of occasionally adjusting a good OCXO  which in turn is used 
as a reference works well for me.I have some that haven't needed adjustment 
for over 2 years (they are still well within one part per billion of being on 
frequency.)

That being said the MV89's were at least fairly in expensive.

Mark Spencer

On 2014-11-10, at 10:05 PM, Joseph Gray jg...@zianet.com wrote:

 You can run at 400 KHz by dividing by 5/5 and 4/9.
 
 True. Either will work.
 
 You said 0.2ppm stability.  What do you need for accuracy and/or how
 are you going to calibrate your setup?
 
 I will initially calibrate the OXCO against my HP GPSDO. Idealy, it will
 only need checking against the GPSDO once a year. Is that asking too much
 for it to be stable over that length of time?
 
 I could simply look up the specs for the various models that I find on
 ebay. However, I know that a lot of the stuff that is sold has been through
 the mill and may not meet spec any more. Thus my request for
 recommendations for models that someone here has actually purchased and
 tested.
 
 Joe Gray
 W5JG
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Re: [time-nuts] Rb as source for ADEV?

[Mark Spencer]

To add a bit to this discussion I recently switched from using from using 
HP5370B's for long term data collection to HP5335's.   For plotting the long 
term drift of two of my more stable OCXO's versus a GPSDO  the 5335's combined 
with Timelab work fine for my limited needs.   Just for grins I compared the 
same sources using both the 5370B's and the 5335's at the same time and 
overlaid the ADEV plots, IIRC the results were identical for Tau's of approx 
2,000 seconds and higher.   
 
At times I also compare the OCXO's to one of my better Rb's (while also 
comparing the OCXO's to the GPSDO) to provide a bit of a sanity check that the 
GPSDO is behaving itself.    I also wrote data collection routines using that 
time stamp all of the data I collect which makes later comparisions 
considerably easier.
 
Regards
Mark S  
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Re: [time-nuts] temperature

[Mark Spencer]

Sorry if this is somewhat off topic, but I'd be interested in more details re 
precision temperature measurement devices.   Have been using an inexpensive USB 
temperature sensor for the last year or so to monitor the temperature in my lab 
and have been looking at the correlation between frequency shifts in some 
ocxo's vs temperature changes.   I should also start taking humidity 
measurements as well at some point. 


 Any pointers re suitable instruments to accomplish this that can be sourced 
via the usual surplus sources would be welcome.

Thanks in advance
Mark Spencer

Sent from my iPad
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Re: [time-nuts] time-nuts Question concerning ADEV measurements

[Mark Spencer]

Hi Bob,  All of my actively used HP5370B's exhibit behavior similar to yours.   
I routinely use a BVA oscillator as the clock for most of my HP5370B's.   I've 
also done some testing comparing the reported adev of other signals using 
various references and swapping between the  internal oscillator and the BVA 
does seem to make a small difference.   

 That being said looking at linear residual plots I have occasionally seen some 
odd results (probably stair case type plots with a recurring pattern iirc sorry 
I am on the road right now and can't check my files re this) on occasion when 
using the clock source as either the start or stop signal.   One day when I 
have some time I will spend a day or so going thru the various use cases 
systematically on all of my active 5370B's and will hopefully get to the bottom 
of this.  

As a side note at least with my HP5370B's I need to be very meticulous about 
cable types, signal levels, trigger settings etc. to be able to notice the 
small difference in performance I get by using the BVA as a clock source.  

Best regards Mark S

Sent from my iPad

On 2013-10-12, at 11:41 AM, time-nuts-requ...@febo.com wrote:

 --
 
 Message: 2
 Date: Fri, 11 Oct 2013 22:27:26 -0400
 From: Robert Darby bobda...@triad.rr.com
 To: time-nuts@febo.com
 Subject: Re: [time-nuts] Question concerning ADEV measurements
 Message-ID: 5258b38e.8030...@triad.rr.com
 Content-Type: text/plain; charset=ISO-8859-1; format=flowed
 
 Thanks John and Magnus.
 
 The reason I asked was that when I check the noise floor of my one and 
 only 5370, the result is noticably superior using the external clock.  
 Since the signal is coming from a single source fed through a MC ZFSC-2 
 splitter and unequal lengths of co-ax, variability in the signal source 
 should have no effect.  When I measure the 5370 with an external clock I 
 see 2.24E-11 at t0=1s with a straight -1 slope; with the internal clock 
 I see 4.43e-11 with periodic noise at about 11, 22,  seconds.  This 
 suggests to me that the internal oscillator is not so hot.
 
 Having only one 5065 I want to use it to both clock the 5370 and serve 
 as the reference; hence the question.  It seems to me by applying the 
 DUT to the start channel one avoids the issue of hitting the same range 
 of start values, assuming some phase change relative to the DUT.
 
 Bob Darby
 
 
 On 10/11/2013 5:36 PM, Magnus Danielson wrote:
 It can be a benefit or a cause of problem. In one end, it could lower
 your noise. The DG535 actually has that as a recommendation, that the
 signal source and the DG535 operate on the same clock.
 
 Another aspect is that you keep banging the same little range of values,
 and that may for that time-base to stop delay be systematically off in
 an unfavourable fashion. The noise of a counter is not always linear
 with that delay, so an asynchronous clock would sweep over the range.
 Then again, if the delay is just right you can utilize the minimum.
 
 Cheers,
 Magnus
 
 
 
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Re: [time-nuts] GPSDO choices

[Mark Spencer]

Hi Paul,

I purchased one of the Miller units and it more than met my expectations (that 
were set by the description on his web site and the information I was able to 
find on the web.)   I also purchased a Fury which also more than met my 
expectations.   I would have no issues repeating either purchase.  Depending on 
your needs and budget both units could be reasonable choices.

For what it is worth when I purchased the Miller unit I was looking for a 10 
Mhz frequency standard for use with my amateur radios, when I purchased the 
Fury I was looking for a new GPSDO for time nuts hobby useage.  I also own 
several other GPSDO's including a surplus Thunderbolt.   The nominal 12 Volt 
power requirements of both the Miller and Fury units are a plus for me but in 
practice I have never run my Fury from any source other than the power supply 
that was shipped with it.

If you would like more specfic info feel free to contact me off list and I can 
try to help.

Regards
Mark Spencer
--



 On Oct 3, 2013, at 11:24 PM, Paul tic-...@bodosom.net wrote:
 
 Iapos;m looking for a new, ready to go, inexpensive desktop GPSDO.  So
 far Iapos;ve only found the Fury and Thunderbolt E.
 
 Are there other reasonable choices e.g. the J R Miller (although Iapos;m
 not sure thereapos;s a source of new TU-30 parts).
 
 Thanks.
 
 --
 Paul
 
 *Say  $2k
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Re: [time-nuts] [time nuts] B.V.A. 8600 for sale

[Mark Spencer]

During my efforts to find a standard that could serve as reference to help 
characterize my FTS1050, I went thru a succession of 10811's, several stand 
alone datum 1000's from the usual auction site, an HP105B, a wenzel from the 
usual auction site etc and none of them came even close to the adev performance 
at tau's of 40 to over 10,000 seconds of the BVA 8600 I purchased.  (I can't 
measure phase noise or adev tau's less than approx 40 seconds.)  The only other 
reference I've been able to acquire that is close to being in the same league 
as the BVA8600 and the FTS 1050 is a single Z3805 at certain tau's (out of 
approx half a dozen assorted GPSDO's.) 

My BVA wasn't inexpensive either but it performed as I expected.  I also 
suspect it out performs the FTS1050 at shorter taus's.   

I also considered buying an HP5065 as an alternative but figured there was less 
to go wrong with a stand alone OCXO.

I figure I got lucky when I acquired my FTS1050 and one of my Z3805's.   I 
don't believe luck played much of a role in my BVA purchase.

Your experience may vary.

Regards Mark S
Sent from my iPad
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Re: [time-nuts] [time nuts] B.V.A. 8600 for sale

[Mark Spencer]

Sorry just to clarify re the particular Z3805 it is the only Gpsdo i have that 
can begin to match the adev of the BVA at shorter tau's (well under 1,000 
seconds.) At longer tau's ie. over several thousand seconds the other Gpsdo's 
become more competitive.

Sent from my iPad

On 2013-08-29, at 1:08 PM, Mark Spencer mspencer12...@yahoo.ca wrote:

 During my efforts to find a standard that could serve as reference to help 
 characterize my FTS1050, I went thru a succession of 10811's, several stand 
 alone datum 1000's from the usual auction site, an HP105B, a wenzel from the 
 usual auction site etc and none of them came even close to the adev 
 performance at tau's of 40 to over 10,000 seconds of the BVA 8600 I 
 purchased.  (I can't measure phase noise or adev tau's less than approx 40 
 seconds.)  The only other reference I've been able to acquire that is close 
 to being in the same league as the BVA8600 and the FTS 1050 is a single Z3805 
 at certain tau's (out of approx half a dozen assorted GPSDO's.) 
 
 My BVA wasn't inexpensive either but it performed as I expected.  I also 
 suspect it out performs the FTS1050 at shorter taus's.   
 
 I also considered buying an HP5065 as an alternative but figured there was 
 less to go wrong with a stand alone OCXO.
 
 I figure I got lucky when I acquired my FTS1050 and one of my Z3805's.   I 
 don't believe luck played much of a role in my BVA purchase.
 
 Your experience may vary.
 
 Regards Mark S
 Sent from my iPad
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Re: [time-nuts] Getting a 5370A tomorrow - How do i test it works

[Mark Spencer]

In addition to the other advice you have received, all of my HP5370B's have 
benefited from having the circuit boards reseated.

The test procedures in the manual for the B version are quite detailed.   I 
presume the A version is similar.

The list archives contain some info about optimum input levels for peak 
performance. 


Regards Mark Spencer

Sent from my iPad
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Re: [time-nuts] Warped back to 1993

[Mark Spencer]

At least one my Z3805's is also showing a date from 1993.
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Re: [time-nuts] 10811 outer oven controller.

[Mark Spencer]

Hi, the recent discussion about 10811's with double oven's caused me to take 
another look at some of the data I've collected from one of my two GPSDO's that 
uses a 10811 double oven OCXO.
  
I realize there is much more to the performance of a GPSDO than the OCXO but I 
can't say I'm unhappy with the performance of this GPSDO and have no complaints 
about the performance of the OCXO in this application.   I expect the data at 
tau 40 seconds is skewed by the noise of the HP5370B.    Sorry that data table 
for these plots shows the data that is more relevant at longer Tau's (it 
doesn't show the values for the comparison between the BVA and the Z3805) but 
the plots show the results at shorter Tau's.
 
As a side note, running standalone none of the 8 or so single oven 10811's I 
own have ever been able to consistently deliver ADEV or MADEV plots in the 13's 
at tau's that I am able to measure (ie 40 seconds.)   
 
Regards
Mark S
 
https://www.dropbox.com/s/jmpnuos0ei324s4/Composite%20MADEV.png?m
 
https://www.dropbox.com/s/3wm2wb6uj9jei7a/Composite%2520ADEV%5B2%5D.png?m
 
 
 
 


--

Message: 6
Date: Mon, 15 Jul 2013 12:16:22 -0700
From: WarrenS warrensjmail-...@yahoo.com
To: Discussion of precise time and frequency measurement
    time-nuts@febo.com
Subject: Re: [time-nuts] 10811 outer oven controller.
Message-ID: 8FAFF758C2AB473EBFAC769FA195DB36@Warcon28Gz
Content-Type: text/plain; format=flowed; charset=iso-8859-1;
    reply-type=response


The Tbolt  LadyHeather plots in my posting are being used as a poor mans 
high resolution TIC tester as discussed at length in other postings, not for 
it's GPSDO output capability.
This is a method that allows a time-nut person that does not have any of the 
high end equipment still the ability to do a lot of the high end state of 
the art time-nut testing.
So in this case, it is valid to compare the results of the EFC changes with 
different types of ovens or even different oscillators such as for finding 
an oscillators tempco and ageing,
as long as the plots are interpreted correctly, because the GPSDO tuning 
settings have very little if any effect on the long term EFC voltage plots.

I have found that one of the largest variables in a GPSDO is the effect that 
temperature change has on the performance of the OCXO being disciplined.
This makes the stability of the OXCO very much a non-constant, in fact 
temperature effect on the OXCO is the largest variable in many setups.
That is why to achieve the best GPSDO performance, or even consistent 
performance between different runs when using a typical single oven GPSDO,
one needs to build a brick house in the basement or put the OXCO under test 
in a temperature controlled environment such as a dual oven or LH 
temperature controlled S/W loop.

All secondary temperature control devices have the same general goal which 
is to minimize or eliminate any fast temperature changes and therefore allow 
the GPSDO to take full advantages of the OCXO's then essentially constant 
intrinsic performance.

Before doing any meaningful comparisons between single and dual oven GPSDOs 
or comparing the difference in optimal tuning settings,
one must first define what the temperature environment is.  If the 
temperature is not allowed to change then there is no difference.
With a good dual oven set up, temperature change will have little or no 
effect, whereas with most time-nut available single oven oscillators 
including the single oven 10811,
temperature variation is the first thing one needs to be consider before 
tuning for optimal performance.

ws

**
from Tom Van Baak (lab) tvb at leapsecond.com
Mon Jul 15 12:22:38 EDT 2013

 Ok, thanks for clarifying. In general the time constant one chooses must 
 reflect both the intrinsic performance of the OCXO (essentially constant) 
 and the realities of GPSDO mechanical, sky-view, and environmental 
 conditions (possibly variable). Disabling an oven during a run is 
 equivalent to a radical change in environment and not re-tuning the loop 
 parameters will lead to sub-optimal or misleading results when plotted.

 If you have time, it would be instructive to re-run the experiment. First 
 with double oven enabled and do your best case ws-tuning. Then disable the 
 outer oven and again do a best-case tuning. The phase/freq/adev plots 
 would be revealing, as well as the (major?) difference in optimal tuning 
 values.

 /tvb (iPhone4)
**
From: WarrenS

 Tom

 My posting and plot was only meant to show the difference in tempco 
 between an undisciplined single and dual oven 10811 osc which in this 
 case is clearly =  60 to 1.
 Your comments  bring up a different subject which is who needs it and how 
 good does a controlled GPSDO oscillator need to be when not in holdover.

 As you know, the purpose of a GPSDO control loop is to make the 
 oscillator's long term stability relatively un-important.
 The longer the measurement 

Re: [time-nuts] Lead acid battery noise levels

[Mark Spencer]

Eric:

 http://tf.nist.gov/general/pdf/1133.pdf

discusses the noise levels of various batteries.

Regards
Mark S
 
 Message: 6
 Date: Wed, 10 Jul 2013 11:11:00 -0700
 From: Eric Williams wd6...@gmail.com
 To: Discussion of precise time and frequency measurement
     time-nuts@febo.com
 Subject: Re: [time-nuts] Lead acid battery noise levels
 Message-ID:
     cafagtrqveohikn4op01myvn6vkdk+bdlsjpwyjrrmxp0sdd...@mail.gmail.com
 Content-Type: text/plain; charset=ISO-8859-1
 
 I wonder if lithium batteries would have a good noise
 figure.  The
 nano-structure of the electrodes give them very large
 surface area and low
 resistance, but the charge carriers are different than other
 types of
 chemistry and I don't know if that's good or bad.
 
 
 
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Re: [time-nuts] Lead acid battery noise levels

[Mark Spencer]

Thanks all for the responses so far.  

Just to clarify I am not charging the batteries while using them to power the 
OCXO.  With a load of less than 150 mA and a nominal capacity of 100 AH I don't 
foresee any issues running the OCXO for a week or so (:  I periodically charge 
the batteries from time to time and probably should discharge a bit more 
frequently anyways (they serve as a backup power source for some other time 
nuts gear.) 
 
Unfortunately the OCXO in question is only spec'd to handle a power source of 
24 volts plus or minus 10% which rules out simply leaving the OCXO directly 
connected to the battery bank while the batteries are float charged.

Best regards
Mark Spencer

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[time-nuts] Lead acid battery noise levels

[Mark Spencer]

Hello, I've just reviewed the thread from earlier this year regarding low noise 
power supplies and some related information about the noise levels of certain 
batteries.Has anyone ever come across any data pertaining to the noise 
levels of common gelled lead acid storage batteries ?

I recently discovered the HP bench supply I've been powering one of my OCXO's 
from is slightly affected  by AC line transients, so I've been running one of 
my OCXO's from a bank of 100 amp hour gelled lead acid batteries.   Apart from 
the lack of glitches due to line transients, the performance of the OCXO 
appears to be better.  Before I embark on a quest for a very low noise power 
supply (or contemplate building one) I'd be curious in knowing roughly what the 
typical noise specs for the batteries are.   

I did find some comments on an audiophile forum that indicated that gel cell 
batteries are not known for low noise levels (:

Best regards Mark Spencer

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Re: [time-nuts] Question about effect of sample interval on ADEV

[Mark Spencer]

Hi, to echo the comments John and Magnus made, I've encountered similar issues 
in the past when using my HP5370B's to compare my FTS 1050 to other standards.  
The fix involved using double shielded RG 400 style cables in my lab (I 
realize the RG 400 standard is not really a standard any more..)   I had 
previously terminated all of the relevant unused inputs and outputs of my time 
nuts gear with 50 ohm terminators.
 
I've also encountered similar issues with several standalone Datum 1000B's and 
needed to add ferrite chokes to the power and double shielded signal cables 
connected to the Datum 1000B to solve the issues.  I suspect the Datums would 
work better inside of a shielded enclosure with bypassed power leads vs sitting 
on a bench in my lab.   My recollection is that the internal oscilator inside 
of the FTS 1050 is typically similar to the Datum 1000B. 
 
My BVA 8600 seems relatively immune to these issues.
 
As a side note I've also found I get better results when using 3 to 6 dB of 
attenuation between the output of my particular FTS1050 and the inputs of my 
particular HP5370B's (I seem to recall there are some other threads in the 
archives about the need to optimize the signal levels to get the best results 
from the HP5370 series counters.)    Your results may differ.
 
Best regards
Mark S

Message: 5
Date: Sun, 7 Jul 2013 14:38:09 -0700
From: John Miles j...@miles.io
To: 'Tom Van Baak' t...@leapsecond.com,    'Discussion of precise
    time and frequency measurement'    time-nuts@febo.com
Subject: Re: [time-nuts] Question about effect of sample interval on
    ADEV
Message-ID: 0b8501ce7b5a$47ea8cf0$d7bfa6d0$@miles.io
Content-Type: text/plain;    charset=us-ascii

This won't be a sampling-interval issue.  It sounds like a beat note.   To
diagnose it, you can use the 5370B in frequency mode (with its internal
timebase) to measure the frequency of the 5065B and the FTS 1050B.  Subtract
the two readings, then see if the reciprocal of the frequency difference
corresponds to the location and spacing of the periodic ADEV bumps.  If so,
that's likely to be the explanation, and you can confirm it by tweaking the
FTS 1050B's frequency and seeing if the beatnote moves accordingly.

As far as getting rid of the artifact is concerned, it may help to use
double-shielded cables, although I don't know if the isolation between the
START and STOP inputs on the 5370B is good enough to eliminate the
possibility of beatnotes in a TI measurement with HF signals on both jacks.
If you are feeding the 5/10 MHz inputs to both START and STOP inputs, try
using a 1-pps divider on the START source.  

You could also try using the 5370B in frequency-count mode, with the 5065A
as an external reference and the FTS 1050B at the STOP input.   There will
be a reduction in ADEV fidelity due to the dead time but it will probably be
less objectionable than the beatnote ripple.

-- john, KE5FX
Miles Design LLC

  My assumption, apparently incorrect, was that the software would take
  the sampling interval into account so that I would get essentially the
  same plot. When I edit a plot changing the sample interval, the trace
  remains essentially unchanged and this seems inconsistent with the
  results noted above. Can anyone explain in relatively simple terms what
  I'm missing?
 
  Thanks,
  Bob Darby




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Re: [time-nuts] HP and other equipment failure

[Mark Spencer]

Re:  HP5370B cooling.
 
I currently have three HP5370B's that have been running for many months in a 
cool room (typical room temperature is under 20 degrees C even in the summer) 
so far without issues.   
Other than placing them away from other heat producing equipment and and double 
checking the ac line voltage supplied to them from a UPS system and the voltage 
setting of the power supply no special precautions were taken.   In the winter 
they provide useful heat to an otherwise cool room in my basement.    Your 
mileage may vary (:
 
One trick I've used on other older equipment with linear power supplies is to 
reduce the AC line voltage (the exact voltage depends on the equipment in 
question) using a variac, to cut down on the power that the pass tranistors in 
the power supplies need to disipate.  I've never bothered to do this with the 
HP5370B's but I be inclined to go down this road before I started blowing extra 
air over them with fans.
 
In general I agree with the comments about the serviceability of the older HP 
gear.  I'm hopefull that I can keep at least two of my four HP5370B's working 
for many years to come.    
 
Regards
Mark Spencer
 
 
 
 
 


--

Message: 1
Date: Fri, 14 Jun 2013 14:26:50 +
From: Mark C. Stephens ma...@non-stop.com.au
To: Discussion of precise time and frequency measurement
    time-nuts@febo.com
Subject: Re: [time-nuts] HP and other equipment failure
Message-ID:
    6c1fe0e5a70c9640b597f869a899c017032f0...@tmpexch.non-stop.com.au
Content-Type: text/plain; charset=us-ascii

Talking of Cooling HP 5370's, I have a 12V fan Gorilla taped to mine fed from a 
wallwart.

Not elegant, but it has reduced the heat sink temperature dramatically.

Is anyone else concerned about the heat sink temperature on the 5370?
Has anyone done a fan modification they would care to share?

Also, my 8566A RF section pass transistor heat sink gets awfully warm too, does 
anyone have a sensible solution?


-marki


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Re: [time-nuts] GSP clock stabilitiy, Rb vs Cs

[Mark Spencer]

The article available for download via this URL contains some history about 
development issues with Rb and Cs Clocks for GPS.   It seems at one point after 
the GPS system was placed into service a development program for new Cs GPS 
clocks failed and by necessity there was a shift towards Rb (at least for a 
period of time.)
 
http://www.insidegnss.com/node/281
 
I'm also speculating that the end of the cold war may have led to less emphasis 
being placed on the GPS system being able to operate for long periods of time 
without ground based intervention which would have further reduced the need to 
develop new and improved Cs clocks for the new GPS satellites.  (In the cold 
war era I recall seeing estimates of how long the GPS system could operate 
without ground based attention.)
 

 
 
 
 
 
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Re: [time-nuts] hp5065b !!!

[Mark Spencer]

Hi, while skimming some articles I found re GPS satellites, I found some 
references to certain buffer gasses in Rb cells working much better with 
optical filters than others.   As far as I know Rb buffer gas formulations are 
not disclosed by the manufacturers so I suspect this info may not be very 
actionable for those of us looking to improve our Rb's.
 
This has been a useful diversion to some academic stuff I'm dealing with this 
weekend (:
 
All the best 
Mark S
 
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