Re: [time-nuts] where can I purchase 794.7 nm VCSEL for building CPT rubidium clock?

[Scott McGrath]

For experimental use you are probably better advised to use a dye laser or a 
Fabry-Perot laser as both are available on the surplus market and both are 
‘tunable’ and leave the VCSEL till you have a functioning prototype 



On Jun 11, 2018, at 4:29 AM, Dana Whitlow  wrote:

I should have written more clearly- the adhesive in question was *not* in
the optical path.

As is usual, variations are possible, one supposedly being that the crystal
that lases
at 1064 nm is also doped with something to make it nonlinear (so I've
read).  I kind of
have my doubts over this, however it seems like asking too much of a single
substance to do "double" duty without some unwanted compromises.

Dana


On Mon, Jun 11, 2018 at 6:06 AM, Bruce Griffiths  wrote:

> The better ones use optically contacted crystals to avoid browning of the
> adhesive due to the high power densities of the 1064nm laser required for
> efficient frequency doubling.
> 
> Brue
>> On 11 June 2018 at 22:52 Dana Whitlow  wrote:
>> 
>> 
>> Mark's description about how (most) green laser pointers work The better
> is a bit in
>> error, and is perhaps
>> over-simplified- the reality is actually more fascinating yet:
>> 
>> First a diode laser operating at around 808 or 809 nm is used to
> optically
>> pump a solid
>> state laser which generates light at 1064 nm.  This light is then
> frequency
>> doubled with an
>> intra-cavity nonlinear element to produce the final  output at 532 nm.
>> For all this to work
>> the optical elements must be critically aligned, and to me the most
> amazing
>> thing about
>> the low selling price is how this alignment is effected so cheaply.  One
> of
>> these units I've
>> opened up has the doubler crystal held down by a lump of cement on one
>> side- it looks
>> for all the world like it must have pushed into alignment and "held"
> there
>> while the cement
>> was cured.  Green pointers made in this way are characterized by quite
> good
>> beam quality
>> and very little wavelength spread from unit to unit. However, they are
>> generally quite
>> delicate and ruined by mechanical shock.
>> 
>> Although not commonly known, at least one outfit (Z-Bolt) is now selling
>> "direct diode"
>> green pointers, where there is just one laser which emits directly in the
>> green, at around
>> 515-530 nm.   These are much more robust, operate well over a wider
>> temperature range,
>> but have the usual poor beam quality (non-circular beam with some
> residual
>> astigmatism)
>> characteristic of diode lasers made with simple collimating optics.  And,
>> the output
>> wavelength spread from unit to unit is quite large.
>> 
>> Dana
>> 
>> 
>>> On Mon, Jun 11, 2018 at 2:43 AM, Mark Sims  wrote:
>>> 
>>> Well, no.  Green laser pointers convert a rather high power 800 nm
> laser
>>> to 1600 nm in one crystal then divide it to 533 nm in another one.
> The
>>> physics and manufacturing of them is best described as black magic.
> They
>>> are cheap because China developed the process to grow the crystals in
> bulk
>>> and crank out zillions of them for consumer products.
>>> 
>>> I suspect that a 1600-ish nm to 800-ish nm converter is not a stock
>>> consumer-quantity device and will cost a pretty penny or two... like a
>>> red/IR laser diode can be had for 50 cents and a telecom VCSEL diode
> can be
>>> $500.
>>> 
>>> --
>>> 
 It cannot be too much, given the fact that these are used in
>>> green laser pointers.
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Re: [time-nuts] Cesium Clock Avialable

[Scott McGrath]

Assuming the seals are good,  i imagine that a few weeks of ion pump time would 
put the tube into ‘ready to use’ condition as recall the tube components have 
been outgassing for the better part of two decades.

Content by Scott
Typos by Siri

On May 19, 2018, at 9:11 AM, djl  wrote:

Hi Doug
I'm visiting just down the coast and could pick up the HP. If not sold I'll 
take it.
Don AJ7LL


> On 2018-05-18 22:04, Doug Millar via time-nuts wrote:
> Hi, I am willing to part with my HP 5061A cesium standard and manual.
> The unit was rebuilt and functioning some years ago and not used since
> then. There is usable cesium in the tube and the unit worked. I have
> not tested it recently. It has a Patek-Philippe analogue clock in the
> front. The unit is in great physical condition.  Asking $600 plus
> shipping from Long Beach, CA. 90806
> I also have an ESI 242D resistance calibrator and a Julie primary
> resistance standard in an oven. Let me know if you are interested.
> Very reasonable.
>  Thanks, Doug K6JEY
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-- 
Dr. Don Latham
PO Box 404, Frenchtown, MT, 59834
VOX: 406-626-4304

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Re: [time-nuts] nuts about position

[Scott McGrath]

Swiftnav has a centimeter accurate multi band receiver RTK-585. Its about 600 
bucks minus antenna.

You would need a choke ring antenna to get centimeter accuracy i think but 
receiver with a quality timing antenna will provide necessary accuracy

On Apr 25, 2018, at 8:06 AM, George Watson  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  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] GPS coordinate differences between APRS.FI and Google Maps

[Scott McGrath]

DATUM perhaps?

Content by Scott
Typos by Siri

On Apr 20, 2018, at 5:20 PM, Russ Ramirez  wrote:

This has probably been mentioned before, but there is a significant
discrepancy between APRS.FI locations for DMR hotspots for example, and
what my Trimble receiver and Google Maps says when I use my address to
lookup the coordinates.

On APRS.FI my location has to be 45.15 N, -93.39 W for the icon to be in
the right location on the map.

On regular Google Maps, my QTH is correct and matches what my Trimble says
via Lady Heather within a few seconds. 45.2586 N, -93.6554 W.

Do any of you know what causes this, and did I do anything wrong possibly?
TIA

Russ
K0WFS
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Re: [time-nuts] Suggest time-and-tech related locations in Switzerland

[Scott McGrath]

swisswatchtours.com

https://m.myswitzerland.com/en-us/factory-and-technical-visits/clock-and-watch-museum-beyer.html

Content by Scott
Typos by Siri

On Mar 13, 2018, at 5:58 PM, David Witten  wrote:

My wife and I are traveling to Switzerland for the last week in May.  I
have never been there before.

I would appreciate suggestions for time / tech sites of interest to visit.

We plan to fly to Zurich, but travel immediately to Geneva and then work
our way back to Zurich by train, stopping (at least) in Bern.

I would like to see what I can at CERN, I plan to attend the Ham meeting in
in Friedrichshafen June 1 - 3.

Dave
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Re: [time-nuts] Replacement Backup Battery for 5065A?

[Scott McGrath]

On 5065A backup batteries,  The  Batteries Plus does a good job of rebuilding 
HP/Agilent battery packs.

I paid 125 a couple years ago to have my 5065A pack rebuilt.   



On Feb 25, 2018, at 2:41 PM, Stan  wrote:

With all this recent 5065A talk I decided to pull mine out of storage and fire 
it up. After a little time to let everything warm up and settle in, I'm happy 
to report that it's working just fine!

My 5065A has the battery backup option, and the battery is the original one 
(1420-0066, Energy Sales p/n ES710, 25.2V 1.4 Ah). Not surprisingly, the 
battery is quite dead. Does anyone any insight about installing a more modern 
battery (SLA or NiMH, perhaps) that will fit in the battery compartment in the 
5065A?

I've looked at a few small 12V/2.2Ah SLA batteries that are physically small 
enough that I should be able to fit a couple in the enclosure and connect them 
in series to get 24 volts out, but I want to wait until either I have assurance 
from someone with more experience than I that this will actually work, or a 
better idea about a more suitable replacement.

Thanks,
Stan

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Re: [time-nuts] The "NAKED" 5065A optical unit

[Scott McGrath]

WRT Rb on the envelope,  the 5065A has a built in 'cold trap' to recover the Rb 
into the reservoir,   Instructions on use are in the manual

Content by Scott
Typos by Siri

On Feb 21, 2018, at 10:33 AM, Attila Kinali  wrote:

On Tue, 20 Feb 2018 10:03:20 -0800
 wrote:

> You do NOT want to take one apart to this level!
> 
> It's never going to operate again.

Why not? Is there something you had to break to open it up this far?

   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] Team of physicists repeats tvb Project GREAT

[Scott McGrath]

Well it will fit in a C-130 or any commercial cargo plane by the looks of the 
trailer.So it could be a flying clock.

Content by Scott
Typos by Siri

On Feb 15, 2018, at 1:02 AM, Michael Wouters  wrote:

Sorry, missed the last character in the URL:

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.118.073601

On Thu, 15 Feb 2018 at 4:42 pm, Michael Wouters 
wrote:

> There's a photo here:
> 
> https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.118.07360
> 
> Cheers
> Michael
> 
> On Thu, 15 Feb 2018 at 1:47 pm, Chris Caudle 
> wrote:
> 
>>> On Wed, February 14, 2018 7:06 pm, jimlux wrote:
>>> At substantially more expense, and with an experimental lattice clock,
>> 
>> Does that schematic figure in the paper imply that the "transportable"
>> strontium and ytterbium clocks are built into trailers instead of the
>> traditional rack enclosure?
>> Actually now that I look more closely it looks like maybe two trailers.
>> Doesn't seem like something that Jim is going to be flying any time soon.
>> 
>> --
>> Chris Caudle
>> 
>> 
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Re: [time-nuts] Does a frequency counter locked to GPS need to "warm up"?

[Scott McGrath]

Yes,   You have removed the reference from the warmup but the input circuits 
still need time to reach thermal equilibrium for most accurate results



On Feb 8, 2018, at 3:34 AM, Azelio Boriani  wrote:

No warmup needed if the counter switches to the external reference. If
the counter uses the external reference to lock the internal one then
it is better to wait until the internal one is stable, maybe the
counter has a standby mode where it appears powered off but the
internal reference is active (usually an ovenized reference). For the
best performance (stability of trigger levels, input amplifiers and so
on) it is better to warmup the whole counter always.

> On Thu, Feb 8, 2018 at 8:33 AM, Chris Wilson  wrote:
> 
> 
>  08/02/2018 07:31
> 
> Does  a  frequency  counter  connected  to a permanently running (Trimble 
> Thunderbolt) GPS
> disciplined frequency standard need to warm up after switch on before 
> readings settle?
> Just curious, thanks.
> 
> --
>   Best Regards,
>   Chris Wilson.
> mailto: ch...@chriswilson.tv
> 
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Re: [time-nuts] Heathkit GC 1000 Most Accurate Question

[Scott McGrath]

I've got one as well replaced that pot with 10 turn pot and electrolytic 
replacement

Content by Scott
Typos by Siri

On Feb 6, 2018, at 9:05 AM, paul swed  wrote:

Exactly they are the small open air pots.
Just one possibility along with the other good suggestions mentioned.
Regards
Paul
WB8TSL

On Tue, Feb 6, 2018 at 7:29 AM, Dave B via time-nuts 
wrote:

> 
>> Bill
>> I see the manual is online for the GC1000.
>> The 1KHZ tone decoder may be suspect in that its drifted off frequency.
> Its
>> a little ne-567 chip with a pot.
>> ne 567s were never all that great...
>> Regards
>> Paul
> 
> 
> 
> 567's are not too bad, not "precision", but not bad.
> 
> Small pot's are not great for long term stability either, especially if
> the track/wiper is exposed.
> 
> 73.
> 
> Dave.
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Re: [time-nuts] Test WWV timecube against Cesium, Rubidium, MASER or other precision time (UT-1) metrology

[Scott McGrath]

The timecube radios were simple superheterodyne AM receivers.   I suspect the 
group delay of the timecubes will be small and fairly consistent due to the low 
component count,   

Yet because of the low quality components performance variability between units 
will be quite high.

A more interesting test would be with a heathkit 'Most Accurate Clock' GC-1000 
which was effectively a HFDO since it used HF WWV signals to discipline its 
timebase.



On Dec 7, 2017, at 3:05 PM, paul swed  wrote:

Pat
Way back in the 90s I measured the color subcarrier frequency of
geostationary satellites. That aren't actually stationary.
I knew the quality of the subcarriers for a number of the networks since we
originated the signals. CBS was Cs others were Rb and still others various
Xtals. I had direct access to the references.
I used an HP5360 and homebrew interface collecting the data on a computer.
I was using a wide variety back then.
No matter. I actually could see over long periods the orbital day to day
and seasonal behaviors. By gosh physics and such in action. The reference
was the 5360s oven oscillator that was quite good. I know times have
changed. The reason to do it was simply because I could.
All of that said I will believe the doppler shifts are your biggest impact
so not sure orders of magnitude really help and may actually confuse. You
will have the effects of earth, the moon and the satellites orbit. Now
thats some serious math and thinking. Some place along the line other great
stuff will work to mess with you.
Regards
Paul
WB8TSL

On Thu, Dec 7, 2017 at 8:48 AM, Patrick Barthelow 
wrote:

> Hello Friends,
> 
> I am picking up locally a couple of vintage analog Radio Shack SW time cube
> radios, 70s vintage, 3 switchable SW frequencies.  Two types, the one
> pictured and a Radio Shack model also that has WWV and Weather channel VHF
> frequencies.
> I am interested in an accurate bench test to compare the analog shortwave
> radios time reporting
> hopefully UT-1 against other available references.  For accuracy, and
> repeatability.   Could eventually add an SDR to the mix, too.
> The 5,10,15 mhz radios obviously are subject to the WWV Ft Collins site,
> propagation distance delays, somewhat calculable, and the vagaries of
> Ionospheric propagation, and, propagation delays between the antenna and
> the measured tap point to the seconds ticks of WWV.   I have some friends,
> microwave professionals, who are also hams here in Auburn who may enjoy
> doing a bench test, with published results, etc.  But wonder if anyone else
> would be interested in borrowing a RS Timecube radio (and/or use an SDR)
> and designing an accurate bench test against available modern standards?
> We are talking probably HUGE  UT-1 errors compared to what this group plays
> with, and that is OK but I think still a worthwhile test, especially if the
> errors using available and cheap equipment are predictable, and repeatable.
> https://forums.qrz.com/index.php?attachments/dscn1187-jpg.400844/
> 
> Another question:  Re precision frequency measurements of spacecraft
> carriers at earth ground stations.  I have found a number of MASER labs,
> willing to help measure a 70 cm UHF carrier of a satellite planned mission,
> circling the moon.  Fun, and overkill yes .   But I would like to know if
> the MASER extra 3 orders of magnitude precision frequency measurement (over
> Rubidium, Cesium)  is useful, or utterly wasted in measuring a lunar
> orbiting spacecraft frequency over as long a period as a month, in a coming
> satellite mission?   Or, are Rubidium and Cesium and GPS disciplined
> references  plenty accurate for accurate spacecraft orbit determinations?
> 
> 
> Best, 73,   Pat Barthelow AA6EG
> apol lo...@gmail.com
> 
> 
> *"The most exciting phrase to hear in Science, the one that heraldsnew
> discoveries,  is not "Eureka, I have found it!"but:*
> "That's funny..."  Isaac Asimov
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Re: [time-nuts] Designing an embedded precision GPS time server

[Scott McGrath]

With 1588 switch architecture counts as well because you have two major classes 
of switch,  blocking and non blocking plus buffering etc.

Most 'enterprise' switches once the flow is set up directly forward frames from 
the ingress port to the egress port each of which also tends to have a fairly 
deep buffer so RTT Is non deterministic on a normal network

Most SOHO  switches use shared ring buffers so their performance is even worse



> On Oct 29, 2017, at 6:29 AM, Leo Bodnar  wrote:
> 

> From: Nick Sayer 
> I believe I’m going to start with one of my GPS module breakouts and an E70 
> XPlained development board. From a hardware perspective, I expect that to be 
> reasonably close to what the final hardware will be (the one thing I would 
> guess would change would be perhaps swapping out the PHY chip for one that’s 
> capable of doing PHY level timestamping, if that’s necessary and possible).

Hi Nick,

Note that PTP/IEEE1588 compliant hardware and NTP use different points in the 
packet as reference timestamps. Timestamping transmitted packets in hardware is 
useless for NTP.  I suspect you know that already.

> But my plan at the moment is to first try to get something that even answers 
> the phone, see how terrible it is, and then see what has to be done to make 
> it truly worthy.

You will find it trivial to get basic functionality working and reasonably 
challenging to get it to work reliably under heavy load and edge cases.  "Heavy 
load" is not an abstract scenario since even on a lightly loaded network there 
is a probability of several clients requesting time simultaneously and network 
switch stacking NTP packets back to back.

If you are making an open source thing you might want to use Laureline NTP 
http://partiallystapled.com/pages/laureline-gps-ntp-server.html as a starting 
point or as a performance yardstick.  I have never seen one so can't comment on 
how well it works but if done properly it should be reasonably solid and agile. 
 I think the guy who designed it also sells them commercially but from what I 
can see the design is also available for others to use.

Leo
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Re: [time-nuts] Symmetricom S200 PSU

[Scott McGrath]

Check to see if PSU is a symmetricom power supply it MAY be a standard merchant 
power supply for which replacements are available from 
newark/digi-key/arrow/ebay etc

Content by Scott
Typos by Siri

On Sep 18, 2017, at 3:21 PM, Clint Jay  wrote:

Hi Chris, if it's not blowing fuses and you're sure you've got all the
capacitors ( low value ones in the primary specifically) then check all the
high value resistors on the primary and continuity from reservoir capacitor
to switching transistor.

The average SMPSU usually doesn't deviate wildly from the application notes
of the switching controller so if there's no specific schematic that might
be a lifeline.



On 18 Sep 2017 20:08, "Lists via time-nuts"  wrote:

Hello Fellow Time Nuts,

Does anyone know where I can get either a circuit diagram or a replacement
PSU for a symmetricon S200 NTP server?

I’ve fixed the original one twice before by replacing all the electrolytic
caps, this time it’s popped something more critical and refuses to come
back to life.

So I either need a new PSU or a circuit diagram so I can fault find on the
original.

I’m in the UK.

Thanks,
Chris


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Re: [time-nuts] R XSRM Rubidium Standard

[Scott McGrath]

As to the point most modern instruments have self calibration,   Most of the 
time 'calibration' is simply the performance check adjustments are not 
performed unless necessary 

The difference being the instruments used in performance test are traceable to 
a national standards body.

So whats referred to as calibration is in reality performance validation.

How do I know this by becoming friendly with the local lab and years ago when i 
worked for govt i used to moonlight at one of the local cal labs.

> On Sep 17, 2017, at 8:57 AM, KA2WEU--- via time-nuts <time-nuts@febo.com> 
> wrote:
> 
> Modern test and radio equipment have self calibration capabilities, older  
> analog do not. Calibration is not always need for  just simple test, but  
> for specification conformation it is useful. A bit  of luck also  helps.
> 
> 
> 
> 
> In a message dated 9/17/2017 8:08:00 A.M. Eastern Daylight Time,  
> drkir...@kirkbymicrowave.co.uk writes:
> 
>> On 15  Sep 2017 10:45, "Scott McGrath" <scmcgr...@gmail.com>  wrote:
>> 
>> Precisely my point,   But when purchasing i  expect to pay for a
> calibration at a minimum.
> 
> I have on occasions  requested sellers to send an item to the manufacturer
> (Agilent or Keysight)  for calibration *before* shipping it to me, offering
> to pay the calibration  cost, but stating that I expect a full refund if the
> item fails the  calibration.
> 
> If a test equipment dealer is confident that something is  working well,
> they should not object to sending it to the manufacturer for  calibration,
> as long as the buyer is willing to pay.
> 
> Of course if a  seller knows little about something,  they are not going to
> do  this,  but the item should be appropriately priced.
> 
> One UK seller  (grace1403) declined to send an Agilent N9912A FieldFox to
> Agilent, because  "Agilent were too fussy"., failing items for trivual
> issues.But he did agree to send it to one of the cal labs he uses. I
> thought it  was a waste of time going to one of the less fussy outfits,   
> but
> bought it anyway. It was then clear on receipt that it was faulty.  (The
> spectrum analyser functionality was ok, but it didn't work as a  network
> analyzer).  He took it back,  but then advertised it on  eBay 6 months
> later. When asked, he said nothing had been done to  it.
> 
> eBay rules about who pays the return shipping charge for an item  that is
> "not as described' keep changing, and may be different on different  sites.
> But on a heavy item shipped internationally,  the postage cost  can be
> comparable or exceed the calibration  cost.
> 
> Dave.
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Re: [time-nuts] Z3801A and Z38XX Issues

[Scott McGrath]

Connect to a terminal emulator and IDQ it you will either see garbage in which 
case serial config is wrong and you need to try a new set of values

Or using a breakout box connect a scope to the txd and rxd lines and compare 
pulse widths 

Content by Scott
Typos by Siri

> On Sep 16, 2017, at 4:22 PM, Bob kb8tq  wrote:
> 
> Hi
> 
> The gotcha is that the 3801 is an “ask for it / get it” protocol. If you 
> don’t 
> get the query formatted correctly, there will be no data coming back. It’s not
> like some other GPSDO’s that just yack all the time.
> 
> Bob
> 
>> On Sep 16, 2017, at 9:27 AM, Brad Stockdale  wrote:
>> 
>> From what I recall, the manual was accurate on the baud, stop bits,
>> parity, etc. Just a few thoughts Make sure that the serial port is
>> working as expected... Do a loop back test if possible. Are you using
>> a USB to Serial adapter? Many of them have some weird quirks. IMHO,
>> FTDI based adapters work better than others.  Forego using the Z38XX.
>> Try using a plain terminal app and see if you get any weird characters
>> echo'd back instead of expected responses. Etc... There are a lot of
>> possible causes when a serial connection isn't working right.
>> 
>> On 9/16/2017 at 12:26 AM, "Richard Solomon"  wrote:Not according to
>> the manual, but then that could be my problem !!
>> 73, Dick, W1KSZ
>> Sent from Outlook
>> 
>> From: time-nuts  on behalf of Bill Hawkins 
>> Sent: Sunday, September 10, 2017 8:16:17 PM
>> To: 'Discussion of precise time and frequency measurement'
>> Subject: Re: [time-nuts] Z3801A and Z38XX Issues
>> 
>> Shouldn't that be 8 data bits?
>> 
>> Bill Hawkins
>> 
>> -Original Message-
>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of
>> Richard
>> Solomon
>> Sent: Saturday, September 09, 2017 4:24 PM
>> 
>> I downloaded and installed Z38XX, configured both the Port and Device
>> to
>> the recommended parameters:
>> Data Rate:  19,200
>> 
>> Parity:  Odd
>> 
>> Data Bits:  7
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Re: [time-nuts] R XSRM Rubidium Standard

[Scott McGrath]

Precisely my point,   But when purchasing i expect to pay for a calibration at 
a minimum.  

 Helps to make friends with the local cal lab though as frequently far better 
pricing can be negotiated if you can get your instruments done on a  
non-critical basis as most of the business of a lab is time sensitive but like 
any other business they have slow periods.   

So your turnaround might be 3-4 weeks instead of 72 hours but the price is half 
of the 72 hour turn



> On Sep 15, 2017, at 4:07 AM, Clint Jay <cjaysh...@gmail.com> wrote:
> 
> Experience has shown me that you can reasonably purchase good, working test
> equipment that's well within calibration tolerances if you are buying the
> more 'common' equipment, 6.5 digit meters, frequency counters, even a
> Stanford SR620...
> 
> I've been very lucky with those, two spectrum analysers and various other
> bits of test gear I'd never have been able to afford any other way, saving
> thousands over what even tatty examples from equipment brokers would have
> cost.
> 
> Yes, you can get bitten and buy a complete POS but you can also take
> sensible precautions and get bargains.
> 
>> On 14 Sep 2017 18:01, "Scott McGrath" <scmcgr...@gmail.com> wrote:
>> 
>> Its an unrealistic expectation that equipment from the well known auction
>> site will work and be 'in-cal'
>> 
>> Its realistic to anticipate several the purchase cost to get well priced
>> instruments back 'in-cal'. But hey if i spend 2 k on a sweeper 3 k to fix
>> and cal it and BlahTest is charging 10k for a ready to go unit im Still 5 k
>> ahead of the game
>> 
>> Content by Scott
>> Typos by Siri
>> 
>>>> On Sep 12, 2017, at 12:10 PM, Dan Rae <dan...@verizon.net> wrote:
>>>> 
>>>> On 9/12/2017 5:58 AM, GandalfG8--- via time-nuts wrote:
>>>> A friend of mine has bought a just out of calibration R  & S XSRM
>> Rubidium
>>>> standard from one of the so called "recyclers" on  Ebay.
>>> Nigel / David,
>>> 
>>> Sorry to hear of your "bargain".   However I doubt very much that the
>> lamp was made by R themselves, like with the Racal 9475 unit it was
>> probably sourced either as a module or as parts from someone like Efratom
>> and one of those lamps will be found to fit. I'm not in a position to help
>> much at present (just coming out of Chemo).  My Racal which was in a
>> similar or worse state when I got that, now comes to life when needed.
>>> 
>>> Cheers,
>>> Dan
>>> ___
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Re: [time-nuts] R XSRM Rubidium Standard

[Scott McGrath]

Its an unrealistic expectation that equipment from the well known auction site 
will work and be 'in-cal' 

Its realistic to anticipate several the purchase cost to get well priced 
instruments back 'in-cal'. But hey if i spend 2 k on a sweeper 3 k to fix and 
cal it and BlahTest is charging 10k for a ready to go unit im Still 5 k ahead 
of the game

Content by Scott
Typos by Siri

> On Sep 12, 2017, at 12:10 PM, Dan Rae  wrote:
> 
>> On 9/12/2017 5:58 AM, GandalfG8--- via time-nuts wrote:
>> A friend of mine has bought a just out of calibration R  & S XSRM Rubidium
>> standard from one of the so called "recyclers" on  Ebay.
> Nigel / David,
> 
> Sorry to hear of your "bargain".   However I doubt very much that the lamp 
> was made by R themselves, like with the Racal 9475 unit it was probably 
> sourced either as a module or as parts from someone like Efratom and one of 
> those lamps will be found to fit. I'm not in a position to help much at 
> present (just coming out of Chemo).  My Racal which was in a similar or worse 
> state when I got that, now comes to life when needed.
> 
> Cheers,
> Dan
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Re: [time-nuts] Restoration of a 5065A - Continued (Ulf Kylenfall)

[Scott McGrath]

Hi Ulf

Also you noted the bulb had the thermionic device,   That's used for 
remigrating the Rb into the reservoir there is a procedure for doing it in the 
manuals on the web.

It can take up to a week to draw all the Rb back into the reservoir after long 
inactivity.Just make sure you use a well regulated power supply while doing 
this procedure

Content by Scott
Typos by Siri

> On Sep 12, 2017, at 7:01 PM, paul swed <paulsw...@gmail.com> wrote:
> 
> Totally agree with Scott.
> On the lamp thats good it lights.
> If you search older threads on Time-nuts you will see that on the FRS
> rubidiums you can heat the lamp with a heat gun and re-migrate the RB off
> of the glass. It makes them re-usable and extends the life very nicely.
> I do not suggest doing this if the lamp lights and the system can be
> recovered. Just something to know about. I have done this several times on
> different FRS units.
> 
> Wow now you have 2 5065s. Nice.
> Regards
> Paul
> WB8TSL
> 
>> On Tue, Sep 12, 2017 at 5:16 PM, Scott McGrath <scmcgr...@gmail.com> wrote:
>> 
>> I would say fix both units
>> 
>> The color of the bulb is simply Rb vapor condensed on the walls of the
>> envelope.
>> 
>> 10811 units are fairly common at good hamfests and ebay
>> 
>> Content by Scott
>> Typos by Siri
>> 
>>> On Sep 12, 2017, at 4:54 PM, Ulf Kylenfall via time-nuts <
>> time-nuts@febo.com> wrote:
>>> 
>>> 
>>> What does the community say: Can the lamp still be useableas a spare, or
>> is the color a sign of end-of-life?
>>> I am considering either use this instrument as spare parts or tryto
>> ___
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Re: [time-nuts] Restoration of a 5065A - Continued (Ulf Kylenfall)

[Scott McGrath]

I would say fix both units

The color of the bulb is simply Rb vapor condensed on the walls of the envelope.

10811 units are fairly common at good hamfests and ebay

Content by Scott
Typos by Siri

> On Sep 12, 2017, at 4:54 PM, Ulf Kylenfall via time-nuts  
> wrote:
> 
> 
> What does the community say: Can the lamp still be useableas a spare, or is 
> the color a sign of end-of-life?
> I am considering either use this instrument as spare parts or tryto
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Re: [time-nuts] Machining some aluminum help!

[Scott McGrath]

I dont want to start a flame war here but I tend to take the recommendations in 
Machinery's Handbook as the basis for process decisions.

for the last 75 years Machinerys Handbook recommend Kerosene as a tapping fluid 
for Aluminum even for forming taps

Btw if anyone here has a machinists tool box that odd rectangular drawer is for 
your copy of Machinery's Handbook

http://new.industrialpress.com/machinery-s-handbook-30th-edition-toolbox.html

WD40 should not be used in any machining operation  

it was initially created for the USAF to remove water (WATER DISPLACER formula 
40) from missile parts which had gotten wet and to leave behind a dry lubricant 
to prevent corrosion and force out water via capillary action

Thats why it works on seized fasteners the capillary action gets the lube into 
the corrosion cells allowing fasteners to move





Content by Scott
Typos by Siri
> On Aug 7, 2017, at 10:36 AM, Joseph Gwinn <joegw...@comcast.net> wrote:
> 
>> On Sat, 29 Jul 2017 22:49:10 -0400, time-nuts-requ...@febo.com wrote:
>> 
>> --
>> 
>> Message: 2
>> Date: Sat, 29 Jul 2017 20:57:56 -0400
>> From: Scott McGrath <scmcgr...@gmail.com>
>> To: Discussion of precise time and frequency measurement
>><time-nuts@febo.com>
>> Subject: Re: [time-nuts] Machining some aluminum help!
>> Message-ID: <f4dd2bec-d51d-43b2-93f3-28a57cd6e...@gmail.com>
>> Content-Type: text/plain;charset=us-ascii
>> 
>> Kerosine is a better tap lube for Aluminum as it is more persistent 
>> and less flammable
> 
> NO.  Kerosene is *not* a good lubricant for _forming_ taps.
> 
> Kerosene (WD-40) and alcohol are good lubricants for _cutting_.
> 
> For _forming_, one needs something very viscous, something that 
> lubricates at very high pressures, at the yield strength of the 
> material being formed.
> 
> Joe Gwinn
> 
> 
> 
>> Content by Scott
>> Typos by Siri
>> 
>>>> On Jul 29, 2017, at 6:41 PM, Joseph Gwinn <joegw...@comcast.net> wrote:
>>>> 
>>>> On Sat, 29 Jul 2017 12:00:02 -0400, time-nuts-requ...@febo.com wrote:
>>>> Send time-nuts mailing list submissions to
>>>>   time-nuts@febo.com
>>>> 
>>>> Message: 7
>>>> Date: Fri, 28 Jul 2017 14:11:09 -0700
>>>> From: "Gary E. Miller" <g...@rellim.com>
>>>> To: Discussion of precise time and frequency measurement
>>>>   <time-nuts@febo.com>
>>>> Subject: Re: [time-nuts] Machining some aluminum help!
>>>> Message-ID: <20170728141109.71aad...@spidey.rellim.com>
>>>> Content-Type: text/plain; charset="utf-8"
>>>> 
>>>> Yo cdel...@juno.com!
>>>> 
>>>> On Fri, 28 Jul 2017 12:46:30 -0700
>>>> <cdel...@juno.com> wrote:
>>>> 
>>>>> After mounting the tap in the drill
>>>>> press and putting a dab of Crisco on the tap I was able to tap each
>>>>> hole to a depth of 7/16" as fast as I could turn the handwheel!
>>>> 
>>>> 
>>>> Cool!
>>>> 
>>>> I suggest you get some real cutting fluid.  The threads will be smoother.
>>> 
>>> I second that.  What I use is a lubricant wax made by Lenox, the saw 
>>> maker.  It's intended for metal-cutting band saws, but works just 
>>> splendid for form taps.  There are many equivalents.
>>> 
>>> By the way, when drilling aluminum, use denatured alcohol as the 
>>> cutting fluid.  This will prevent aluminum gumming up the cutting edge 
>>> of the drill.
>>> 
>>> And, as others have mentioned, one does not use the same size drill for 
>>> forming taps as for cutting taps.  The diameter accuracy required can 
>>> only be achieved by using the correct number (versus fractional) drill 
>>> bit size.  Do not use Chinese drill bits - steel not good enough.  US, 
>>> Japan, Germany et al are OK.
>>> 
>>> Joe Gwinn
>>> 
>>> 
>>>> RGDS
>>>> GARY
>>>> 
> ---
> 
>> 
>> End of time-nuts Digest, Vol 156, Issue 38
>> **
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Re: [time-nuts] Machining some aluminum help!

[Scott McGrath]

Kerosine is a better tap lube for Aluminum as it is more persistent and less 
flammable

Content by Scott
Typos by Siri

> On Jul 29, 2017, at 6:41 PM, Joseph Gwinn  wrote:
> 
>> On Sat, 29 Jul 2017 12:00:02 -0400, time-nuts-requ...@febo.com wrote:
>> Send time-nuts mailing list submissions to
>>time-nuts@febo.com
>> 
>> Message: 7
>> Date: Fri, 28 Jul 2017 14:11:09 -0700
>> From: "Gary E. Miller" 
>> To: Discussion of precise time and frequency measurement
>>
>> Subject: Re: [time-nuts] Machining some aluminum help!
>> Message-ID: <20170728141109.71aad...@spidey.rellim.com>
>> Content-Type: text/plain; charset="utf-8"
>> 
>> Yo cdel...@juno.com!
>> 
>> On Fri, 28 Jul 2017 12:46:30 -0700
>>  wrote:
>> 
>>> After mounting the tap in the drill
>>> press and putting a dab of Crisco on the tap I was able to tap each
>>> hole to a depth of 7/16" as fast as I could turn the handwheel!
>> 
>> 
>> Cool!
>> 
>> I suggest you get some real cutting fluid.  The threads will be smoother.
> 
> I second that.  What I use is a lubricant wax made by Lenox, the saw 
> maker.  It's intended for metal-cutting band saws, but works just 
> splendid for form taps.  There are many equivalents.
> 
> By the way, when drilling aluminum, use denatured alcohol as the 
> cutting fluid.  This will prevent aluminum gumming up the cutting edge 
> of the drill.
> 
> And, as others have mentioned, one does not use the same size drill for 
> forming taps as for cutting taps.  The diameter accuracy required can 
> only be achieved by using the correct number (versus fractional) drill 
> bit size.  Do not use Chinese drill bits - steel not good enough.  US, 
> Japan, Germany et al are OK.
> 
> Joe Gwinn
> 
> 
>> RGDS
>> GARY
>> ---
>> 
>> End of time-nuts Digest, Vol 156, Issue 36
>> **
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Re: [time-nuts] Software for Spirent GSS4100 GPS simulator

[Scott McGrath]

As a spirent user in another context

Most Sprient software is supplied only if you subscribe to software maintenance 
which is understandable due to the limited customer base and the concomitant 
small pool of possible revenue they simply cant afford to give software away.



> On Jun 25, 2017, at 6:50 AM, Peter Vince  wrote:
> 
> Our favourite auction site has someone selling a Spirent GSS4100 GPS
> simulator cheap, "for parts", as it is untested.  I'm guessing the vendor
> has no clue HOW to test it, especially as they have no software to go with
> it, so am hoping it might actually be OK.  Worth a punt, anyway.  However,
> the download link for the "SimCHAN v2.02" software on the Spirent site
> doesn't work, and they have yet to reply to my email.  Does anyone have a
> copy of that software?  While not "freeware", it was provided with the
> equipment (on a CD), and is no use without the hardware, and vice-versa,
> and if that CD has been lost by the original hardware owner, it seems
> reasonable for the new owner to ask for a copy of said software, and so my
> conscience is clear in asking for a copy.
> 
> Thanks in advance, Peter Vince
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Re: [time-nuts] Powering up a long inactive 5061A

[Scott McGrath]

First you will need to power it up in Cs Off state and monitor the ion pump 
current by periodically switching to Cs On

If you have a possibly good tube ion pump current should drop to zero in a few 
days to 3 weeks

Thats your first step

> On Jun 15, 2017, at 2:02 AM, Hugh Blemings  wrote:
> 
> Hi,
> 
> I've been assisting with the cataloguing and, where possible, testing of a 
> bunch of test equipment from a deceased estate.
> 
> One of the items is a 5061A which best I can tell has not been powered on for 
> over a decade.  The High Performance tube has a warranty expiration date of 
> 1988.  Serial number is 1936A01567 and has Option 01 and 04 and has the 
> digital rather than analogue clock.  Minor but it's missing the bottom cover.
> 
> My intuition is to set it to one side until I can become familiar with the 
> operating manual and potentially bring power up to it slowly with a Variac or 
> similar.
> 
> I'd be curious as to the time-nuts view on whether this degree of caution 
> warranted ?
> 
> I suspect the Cs tube is long dead, but maybe I'll be pleasantly surprised ?
> 
> Would welcome feedback on sensible/cautious first steps with the unit - 
> initial need, if possible, is a "simple" go/no go/does it power on ?
> 
> Cheers/73
> Hugh
> VK3YYZ/AD5RV
> 
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Re: [time-nuts] Frequency counter questions

[Scott McGrath]

The heterodyne trick has been done before the first 
'Modern' frequency counter the HP 5245 used plug ins to extend its range to 18 
Ghz by doing exactly that.   The plug in contained a tunable LO  mixer and 
indicator to show tuning lock

These were a pain to use but they beat the 'frequency meters' by a mile 

Content by Scott
Typos by Siri

> On Apr 26, 2017, at 2:52 PM, al wolfe  wrote:
> 
> such
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Re: [time-nuts] HP8640

[Scott McGrath]

Ulrich

I have an operational 8640 

Content by Scott
Typos by Siri

> On Jun 7, 2017, at 11:35 AM, Dave Daniel  wrote:
> 
> There is, or was, a member of the Yahoo hp_agilent forum who was making metal 
> replacement gears for the HP8640. I believe several members replaced the 
> plastic gears with the new metal ones and were able to bring their 
> instruments back to life.
> 
> DaveD
> 
>> On 6/7/2017 8:56 AM, Bert Kehren via time-nuts wrote:
>> I think it will be difficult to find a well working 8640, plastic gears
>> will have by now totally disintegrated. What part of it do you need, I may
>> have  something left.
>> Bert Kehren
>>In a message dated 6/6/2017 9:06:05 P.M. Eastern Daylight Time,
>> time-nuts@febo.com writes:
>> 
>> Hi , I  am trying to find an well working  HP 8640 to do some  measurements
>>  like SSB  FM and AM noise.
>> 
>> Who can help ?  73 de Ulrich  N1UL
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> 
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Re: [time-nuts] Two pieces of old General Radio Freq. Nuts

[Scott McGrath]

The GenRad 874 connector was good to 4.5 Ghz  and took a Banana plug in the 
center conductor without changing electrical characteristics!!!

http://www.ietlabs.com/pdf/GR_Experimenters/1948/GenRad_Experimenter_Oct_1948.pdf

Not bad for a connector designed in 1948!

It was largely supplanted by the APC-7 connector from Bunker-Ramo which was 
also a hermaphrodite design but had a 18 Ghz frequency limit

Lots of Tek calibrators used this connector due to its good impedance matching 
without requiring obsessive connector maintenance as the APC-7 does (cleaning, 
gauging and finger replacement)





Content by Scott
Typos by Siri
> On May 28, 2017, at 12:21 AM, djl  wrote:
> 
> Yep, GR once made the best. The GR connector had at least three things going; 
> as noted hermaphroditic. No need for several sexes. Second, they are seamless 
> 50 ohms, very very small reflections at the connection. Third, banana plugs 
> (also a GR idea, I think) fit in the center "post" of the connector without 
> wrecking anything. GR also made an hermaphroditic connector good to several 
> GHz before passing into legend. . .
> Don
> 
> 
>> On 2017-05-27 05:01, Bob kb8tq wrote:
>> Hi
>>> On May 26, 2017, at 11:21 PM, Gary Woods  wrote:
 On Mon, 22 May 2017 05:59:59 -0700, you wrote:
 https://goo.gl/photos/tygN5ZFeFLUhc4zX6
 Near Portland Oregon
>>> Neat stuff...did anybody but GR use those hermaphrodite connectors?
>> At one time, GR was pretty much the only source for a wide range of RF
>> and microwave test gear. Anything that was going to work with that gear
>> may have come with the GR connectors. That includes stuff like attenuators,
>> cables, and other bits of “lab clutter”. When you checked the box for the
>> GR connectors, the price went up quite a bit. That made the gizmos with
>> the connectors on them a bit more rare than they otherwise would be.
>> Bob
>>> I have
>>> an adapter for them that came with a wide-band amplifier; "delay line"
>>> type, with a whole row of, I think, 6AK5s in it.
>>> --
>>> Gary Woods AKA K2AHC- PGP key on request, or at 
>>> home.earthlink.net/~garygarlic
>>> Zone 5/4 in upstate New York, 1420' elevation. NY WO G
>>> ---
>>> This email has been checked for viruses by AVG.
>>> http://www.avg.com
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> 
> -- 
> Dr. Don Latham
> PO Box 404, Frenchtown, MT, 59834
> VOX: 406-626-4304
> 
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Re: [time-nuts] Machining some aluminum help!

[Scott McGrath]

Corby

Unless you have the tubing and plates machined flat they will leak as the 
tubing sides are not guaranteed to be flat and parallel wrt each side and 
aluminum plate stock is not flat unless you purchase 'tooling plate' which is 
ground parallel on both sides

So creating a seal is problematic at best

Content by Scott
Typos by Siri

> On May 19, 2017, at 4:23 PM,   wrote:
> 
> Thanks everyone.
> 
> Not looking for a redesign, just figuring out how to get the holes
> drilled and tapped.
> 
> I have come up with a scheme that looks promising and will let you know
> how it goes.
> 
> The enclosure only has to hold +.1PSI of dry nitrogen without leaking.
> 
> It will have a pressure sensor inside to allow long term monitoring.
> 
> From the feedback and some research I will be reducing the depth of the
> threaded portion.
> 
> Cheers, 
> 
> Corby
> 
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Re: [time-nuts] Machining some aluminum help!

[Scott McGrath]

Content by Scott
Typos by Siri

> On May 18, 2017, at 4:34 PM,   wrote:
> 
> Well that generated a lot of advice and thanks for it!
> I think I might do it myself and go with a 1/2" hole depth and 1/4"
> threaded depth.
> I'll get some of that Aluminum Tap magic, some new taps and new drill
> bits.
> Good idea about drilling the end plates first and drilling thru to match.
> Between the end plate and the tube is a gasket that needs to seal
> pressure and moisture tight. That's why I used 5 per side.
> 
> Will let you know how it turns out.
> 
> Cheers,
> 
> Corby
> 
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Re: [time-nuts] Machining some aluminum help!

[Scott McGrath]

If you need pressure moisture tightness you are going to want to have machinist 
mill tube ends and plates flat if you take off say 075-100 thousands deep and 
.225 thousanths around edge of plate and have machinist predrill holes in cover 
plate you will have both a tight seal and drill guide for the tube drilling and 
tapping.


Content by Scott
Typos by Siri

> On May 18, 2017, at 4:34 PM,   wrote:
> 
> Well that generated a lot of advice and thanks for it!
> I think I might do it myself and go with a 1/2" hole depth and 1/4"
> threaded depth.
> I'll get some of that Aluminum Tap magic, some new taps and new drill
> bits.
> Good idea about drilling the end plates first and drilling thru to match.
> Between the end plate and the tube is a gasket that needs to seal
> pressure and moisture tight. That's why I used 5 per side.
> 
> Will let you know how it turns out.
> 
> Cheers,
> 
> Corby
> 
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Re: [time-nuts] Re. DIY atomic "resonator"

[Scott McGrath]

One of the challenges with todays new WiFi standards i.e. 802.11ac/ad/ax is the 
doppler from office fluorescent lighting systems so much so that channel 
emulators like the Anite Propsim F8 emulate it at various pseudoranges to the 
AP and STA

That said old school noise sources were indeed gas discharge tubes

> On Apr 12, 2017, at 2:18 PM, jimlux  wrote:
> 
>> On 4/12/17 10:28 AM, Dave B via time-nuts wrote:
>>> On 12/04/17 17:00, jimlux wrote:
>>> 
>>> Subject: Re: [time-nuts] Re. DIY atomic "resonator"
>>> Message-ID: 
>>> Content-Type: text/plain; charset=utf-8; format=flowed
>>> 
 On 4/11/17 11:09 AM, Mark Sims wrote:
 Apparently fluorescent tubes continuously emit a lot of other microwave 
 signals.  I once built a  homodyne doppler "speed" radar kit (used a 
 coffee can for the antenna).  The way you calibrated it was to point it at 
 a florescent tube and and adjust the reading to a specific value.
 
 --
>>> That's not because the tube is emitting..  It's a target reflector
>>> turning on and off at twice line frequency.
>>> In most homodyne radars, you filter out the DC (the reflections from
>>> stuff that's not moving), so anything that pulses on and off creates
>>> nice output.
>> 
>> This patent would seem to confirm that discharge tubes do generate
>> microwave noise, and with a DC powered tube too.  (Would different
>> gasses produce different microwave spectra?)
>> 
>> http://www.google.co.uk/patents/US2942204
> 
> They generate broadband noise - they're used as high power noise sources for 
> calibration.
> 
> Bracewell (I believe) used fluorescent tubes (driven by a reasonably stable 
> source) as a calibration and timing reference at a astronomy array -
> http://articles.adsabs.harvard.edu//full/2005JAHH8...75B/077.000.html
> 
> R. Bracewell and G. Swarup, "The Stanford microwave spectroheliograph 
> antenna, a microsteradian pencil beam interferometer," in IRE Transactions on 
> Antennas and Propagation, vol. 9, no. 1, pp. 22-30, January 1961.
> doi: 10.1109/TAP.1961.1144935
> 
> I particularly like the inclusion of "milling machines" in the keyword list
> keywords: {Microwave interferometry;Planar arrays;Radio telescopes;Reflector 
> antennas, arrays;Solar radiation;Brightness 
> temperature;Corona;Frequency;Microwave antennas;Milling 
> machines;Monitoring;Moon;Phase modulation;Sun;TV}
> 
> And fluorescent tubes have been used as a broad band source in a classroom 
> demo
> https://www.researchgate.net/publication/276280926_Demonstrating_the_Principles_of_Aperture_Synthesis_with_the_Very_Small_Radio_Telescope
> 
> 
> 
> I would suspect that the radiated field has some spectral bumps in it, 
> probably related the physical dimensions.  I doubt it would have any discrete 
> lines (although maybe it does..)
> 
> 
> 
> 
> 
>> 
>> I recall seeing such things sold surplus back in the early 70's, pity I
>> didn't know what they were back then.
> 
> There are also gas tubes in waveguides used as Radar T/R switches. when the 
> main bang happens, the tube ionizes shorting the waveguide and protecting the 
> receiver downstream.
> 
> 
>> 
>> There is also mention of huge mismatches in the guide when the tube was
>> not powered, that would support the homodyne speed calibration comment
>> by pointing it at a working (AC powered) florescent tube.  As Jim said,
>> a 100 (or 120) Hz "modulated reflector."
> 
> Yep.  There's been a fair amount of work over the past decades on using 
> modulated reflectors for measuring antenna patterns (e.g. on phased arrays).  
> You can have a diode/dipole suspended by resistive leads (with an impedance 
> of 377 ohms/square that are invisible) and turn it on and off.
> 
> Bolomey (I think) had an array of modulated reflectors, so you could measure 
> multiple points in the near field at the same time, and only need to scan in 
> one dimension. I can't remember if the reflectors were modulated at different 
> rates or with PN codes - either would work to separate the responses.
> 
> 
>> 
>> Regards to All.
>> 
>> Dave G0WBX (or G8KBV both still valid.)
>> 
>> ~~~
>> 
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Re: [time-nuts] Looking for Gen Rad 1101A oscillator/parts

[Scott McGrath]

The Harvard collection of scientific instruments has one BTW 

http://waywiser.rc.fas.harvard.edu/view/objects/asitem/People@5686/57/displayDate-asc?t:state:flow=028d1ae2-7ea9-4238-9161-a1bf858d81d8

You might to contact them and see if they have any documentation and or photos 
they can share

Content by Scott
Typos by Siri

> On Apr 6, 2017, at 9:04 PM,   wrote:
> 
> Yes, I have the 1190 crystal and the socket. That is one of the driving 
> factors for me to get the oscillator functional again. I am hoping someone 
> has parts of another 1101A that is missing the crystal bar.
> 
> John
> 
> 
>  Bob kb8tq  wrote: 
>> Hi
>> 
>> I have seen only one of them that still had the 100 KHz bar in it in good 
>> shape. That
>> was back in 1973 and I have no idea at all what happened to that one. It was 
>> at a 
>> surplus outfit in Indiana that is long since gone out of business. 
>> 
>> Bob
>> 
>>> On Apr 6, 2017, at 6:04 PM, Pete Lancashire  wrote:
>>> 
>>> I took a gamble at a swap meet a few years ago $5 but did not have time etc
>>> to look inside get home no rock but nice wooden box :-)
>>> 
 On Thu, Apr 6, 2017 at 2:21 PM, Bob kb8tq  wrote:
 
 Hi
 
 Does your unit have the 1190 100 Kc quartz bar still in it? If so does the
 mount appear to be intact?
 
 At this late date, replacing that resonator is not going to be easy.
 
 Bob
 
> On Apr 6, 2017, at 3:58 PM, jmfra...@cox.net wrote:
> 
> I am trying to restore a clunker  General Radio 1101A crystal
 oscillator. The unit I have is missing several parts including the mercury
 thermostat switch and parts of the oven box, and maybe more. I am looking
 to buying one or more other clunkers to get at least one of these historic
 devices operational again. Any help appreciated.
> 
> John Franke WA4WDL
> 4500 Ibis Ct
> Portsmouth, VA 23703
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Re: [time-nuts] HP-59309A Clock counts only seconds

[Scott McGrath]

A 4011 is an inexpensive part,   Mouser still carries them,   I would NOT buy a 
chinese part.  Generally ESD mishandling is the cause of short component life

Content by Scott
Typos by Siri

> On Apr 3, 2017, at 7:43 PM, Jeremy Nichols  wrote:
> 
> I have a new-to-me HP-59309A HP-IB Digital Clock. The clock works on both the 
> internal crystal oscillator and on an external 10 MHz standard (GPSDO). 
> However, it counts only to 60 seconds and then repeats without updating the 
> minutes digit. The TIME SET (FAST and SLOW) push-buttons work but again, the 
> count will not update minutes and hours, only seconds. The DAY SET procedure 
> works correctly for days and months. All the other switches and buttons do 
> what they are supposed to do. Using my 10526T logic pulser I can force the 
> minutes and hours counters to work. The power supply is in good condition 
> (after replacement of a few components) and I see no other problems (yet).
> 
> Tracing the clock signal through the logic circuitry brought me to U3 on the 
> A4 board. This (U3) is a 4011 quad 2-input NAND gate in a 14-pin DIP package. 
> It "connects" the seconds counter to the minutes counter and appears to have 
> failed. One of the people on the email list 
>  commented that the 4000 series CMOS 
> chips have a known limited lifetime. Since these parts are no longer in 
> production, the writer expressed the concern that any parts I might find to 
> buy may be DOA.
> 
> Before I go hunting for parts, I'd appreciate hearing from anyone in the 
> group who has experience with the 59309A Clock and/or the 4000-series CMOS 
> family. In particular, are there modern equivalents to my 4011 chip? If the 
> 4000's really do have a limited lifetime I'd rather use a substitute.
> 
> Jeremy, N6WFO
> 
> 
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Re: [time-nuts] Time Dilation tinkering

[Scott McGrath]

Ive been playing with one for work for the past few weeks and the Nor Easter 
which blew through NE did not affect short term ADEV with Tau < 1000s and that 
had a signficant drop in local barometric pressure for several hours

As to long term controlled studies no have not had opportunity to do so yet so 
that was an off the cuff observation based on the storm and not scientific data.

I'd be interested in any other observations around the same time though if 
anyone else is running a CSAC in NE


> On Mar 21, 2017, at 8:25 PM, Bob Camp <kb...@n1k.org> wrote:
> 
> Hi
> 
> Ummm … e …. it’s a gas cell standard. I’d bet there is a pressure effect.
> 
> Bob
> 
>> On Mar 21, 2017, at 7:01 PM, Scott McGrath <scmcgr...@gmail.com> wrote:
>> 
>> Noted
>> 
>> However CSAC not subject to barometric effects as Rb units are
>> 
>> Content by Scott
>> Typos by Siri
>> 
>>>> On Mar 21, 2017, at 4:18 PM, jimlux <jim...@earthlink.net> wrote:
>>>> 
>>>> On 3/21/17 12:51 PM, Scott McGrath wrote:
>>>> Or perhaps use the Symmetricom CSAC ...
>>>> 
>>>> Relatively expensive but might work
>>>> 
>>> 
>>> 
>>> The CSAC  is 8E-12 AVAR at 1000 seconds, comparable to a Rb.
>>> 
>>> 
>>> See also http://tycho.usno.navy.mil/ptti/2011papers/Paper27.pdf
>>> which shows a bit better performance (3E-12 @ 1000s), but the best 
>>> performance appears to be at 10,000 seconds.
>>> 
>>> 
>>> but don't you need better?
>>> Attila wrote> You will need a stability 1e-14 @1d.
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Re: [time-nuts] HP5061B Ion Current

[Scott McGrath]

John makes a good point about the ionizer filament has anyone done a 'slow 
start' system for the Ionizer filament?   

I.e. Limit the inrush current as is done for expensive high power transmitting 
tubes?




> On Mar 21, 2017, at 9:44 PM, Donald E. Pauly  wrote:
> 
> It looks like that there is about 10% hysteresis on the cesium trip
> off/on. That may not be enough to prevent cycling on and off.   I may
> not have made it clear but instability in the +3,500 voltage makes a
> big difference in the threshold ion current required for activation.
> If it fades it can require a 10 uA smaller ion current to activate
> cesium.
> 
> -- Forwarded message --
> From: John Miles 
> Date: Tue, Mar 21, 2017 at 5:41 PM
> Subject: Re: [time-nuts] Fwd:  HP5061B Ion Current
> To: Discussion of precise time and frequency measurement
> , rwa...@aol.com
> 
> 
> That's some very nice work, Donald.  Looking back, I have junked one
> or two Cs tubes that might have been usable if I'd thought through the
> problem of high ion pump current as you and KB7APQ seem to have done.
> 
> Another good reason to raise the lockout threshold would be to cut
> down on the repetitive ionizer filament cycling that the tube will
> otherwise undergo when you first fire up the oven.  That phenomenon
> always makes me rally nervous.
> 
> -- john, KE5FX
> Miles Design LLC
> 
>> -snip-
>> When we overrode the cesium lockout at 29 μA or so of ion current, we
>> needed only minor front panel adjustments for beam current of 20 μA.
>> (We shorted across A15 R-4.) Our last ion current before power supply
>> modifications at risen to 39 uA.  Beam current has been stable.
>> 
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Re: [time-nuts] Time Dilation tinkering

[Scott McGrath]

Noted

However CSAC not subject to barometric effects as Rb units are

Content by Scott
Typos by Siri

> On Mar 21, 2017, at 4:18 PM, jimlux <jim...@earthlink.net> wrote:
> 
>> On 3/21/17 12:51 PM, Scott McGrath wrote:
>> Or perhaps use the Symmetricom CSAC ...
>> 
>> Relatively expensive but might work
>> 
> 
> 
> The CSAC  is 8E-12 AVAR at 1000 seconds, comparable to a Rb.
> 
> 
> See also http://tycho.usno.navy.mil/ptti/2011papers/Paper27.pdf
> which shows a bit better performance (3E-12 @ 1000s), but the best 
> performance appears to be at 10,000 seconds.
> 
> 
> but don't you need better?
> Attila wrote> You will need a stability 1e-14 @1d.
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Re: [time-nuts] Time Dilation tinkering

[Scott McGrath]

Or perhaps use the Symmetricom CSAC ...

Relatively expensive but might work

> On Mar 21, 2017, at 8:08 AM, Attila Kinali  wrote:
> 
> On Tue, 21 Mar 2017 13:38:51 +1100
> Hugh Blemings  wrote:
> 
>> This got me to wondering if a Rubidium based standard might do the trick 
>> - the Efratom SLCR-101s seem readily available for ~USD$200 mark.
> 
> As TvB wrote, a single one will not do the trick. You will need 
> a stability 1e-14 @1d. IIRC most Rb standards floor out at 1e-12 to 1e-13
> somewhere between 1k and 100k seconds. Even the Super-5065 has a floor
> of about 3-4e-14 (unless our friends here improved on this already).
> 
> There will be a few things that you will need to do, if you want to go
> with Rubidiums:
> 1) Stabilize or compensate for environmental effects (temperature, air 
> pressure)
> 2) Build ensembles of Rb clocks.
> 
> The former is to prevent the ADEV from "turning upwards" again and
> keep the Rb's as stable as possible as long as possible. I have no
> experience how much this helps, but I suspect, with the correct modeling
> that you could get the ADEV to be flat up to a day, maybe even two.
> You will have to include aging and drift of the cell itself in the model.
> This also means that you will have your Rbs running for a few weeks/months
> prior to any measurement so that the aging settles down a bit.
> 
> The ensemble is to get the ADEV down. Averaging of clocks with the same
> noise decreases the ADEV by the square root of the number of clocks used.
> If you are close to the ADEV you need, the averaging will help you getting
> it further down. Unfortunately, getting from 1e-13 down to 1e-14 is
> impractical as you'd need 100 clocks to average over But a factor
> of 2 to 3 should be possible.
> 
> 
> Alternatively, you can ask Oscilloquartz whether they let you borrow
> two of their new OSA3300 for a publicity stunt :-)
>
>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] Antique precision timing device without electronics

[Scott McGrath]

For the bulb you can probably replace it with a W1A or AR-1bulb which is an 
argon bulb commonly used in old school contact printers they have a purple hue 
and also emit long wave UV light   

I doubt if they are still manufactured but a photo shop or studio or chemist 
shop which developed film which has been in business a long time 60's and 70' 
is likely to have some as they were very common them

Content by Scott
Typos by Siri

> On Mar 16, 2017, at 5:22 AM, Morris Odell  wrote:
> 
> Hi all,
> 
> I was recently asked to resurrect this interesting device by a colleague who 
> collects antique scientific instruments. It’s a "Chronoscope" made by the H. 
> Tinsley company in London in the early 20th century and used to measure time 
> intervals with the precision of those days. It's large and heavy in a 
> polished wooden case with a top deck that hinges up to reveal the innards. 
> 
> The timing reference is a large tuning fork about 30 cm (1 foot) long and 
> running at 25 cps. It's normally in a glass fronted housing (removed for the 
> video) that includes a pair of hinged mechanical arms for starting it. It's 
> maintained in oscillation by an electromagnet and contact arrangement powered 
> from a 12V DC supply. The fork amplitude is controlled by a rheostat - too 
> much and the tines impact on the magnet. The video frame rate makes the fork 
> look slower than it actually is. I was able to extract a signal and measure 
> the frequency with a modern GPS disciplined counter - it's 0.007% off its 
> specified 25 Hz! The frequency is too low for my HP 5372A so I was not able 
> to easily get an idea of stability or do an ADEV measurement. The fork has 
> quite a high Q and takes over a minute to stop oscillating after the power is 
> turned off. There's a built in higher voltage AC power supply, probably a 
> mains transformer, potted in beeswax in a polished wooden box inside that is 
> intended 
 to
>  energise a large neon strobe lamp used to adjust the fork. Unfortunately the 
> lamp was not with the unit and is no doubt irreplaceable. 
> 
> The 25 Hz signal is filtered by an LC network  and used to run a synchronous 
> motor in the Chronoscope unit. Synchronous motors not being self-starting, 
> you need to tweak a knob to get it going - there's a joke in there but I 
> can't for the life of me think what it could be  The "Contact" switch and 
> associated socket on the back controls an electromagnetic clutch that 
> connects the clockwork counter mechanism to the motor and the contact "on" 
> time is indicated on the dials with 10 mS resolution. 
> 
> There's not a single active device in there and after a clean and lube it 
> runs very nicely from a modern 12V DC plugpack. My friend is very pleased 
> with it and it will take pride of place in his collection. 
> 
> I'd be interested to know if any time nuts have knowledge or experience of 
> this lovely instrument.
> 
> A video of it is at  https://youtu.be/i5S8WS9iN_E
> 
> Enjoy!
> 
> Morris
> 
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Re: [time-nuts] Bye-Bye Crystals

[Scott McGrath]

>From the tone of the letter it sounds like the bank cancelled line of credit,  
> 

Which is stupid given that much of their line is military which is getting a 
huge boost in spending 

> On Mar 11, 2017, at 4:56 PM, Bryan _  wrote:
> 
> Disappearing or manufacturing just moving overseas?. Video at the bottom is 
> interesting, classic.
> 
> 
> http://hackaday.com/2017/03/11/so-long-and-thanks-for-all-the-crystals/
> 
> 
> 
> -=Bryan=-
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Re: [time-nuts] HP5328A + NI GPIB-ENET/1000

[Scott McGrath]

The issue with talk-only is you don't have remote control of instrument 
settings hence talk only

Content by Scott
Typos by Siri

> On Feb 24, 2017, at 11:47 AM, James Peroulas  wrote:
> 
> Thanks for the suggestions Scott(s)!
> 
> It ended up being something simple. With no signal coming into the 5328A,
> it did not produce any output over GPIB. I would have expected a continuous
> readout of 0Hz. Once I applied a signal, a simple GPIB "read" request
> returned the measurements I needed. No need to send any commands. This is
> in talk-only mode.
> 
> James
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Re: [time-nuts] HP5328A + NI GPIB-ENET/1000

[Scott McGrath]

'Talk Only' mode responds to serial poll mode which is querying all instruments 
on the bus.   And it's primary use is in automated test systems 

You want to disable talk-only mode for normal interactive control of an 
instrument using GPIB

Content by Scott
Typos by Siri

> On Feb 23, 2017, at 1:37 AM, James Peroulas  wrote:
> 
> Does anyone have experience using older HP equipment with the NI
> GPIB-ENET/1000 GPIB to ethernet box? Is this even possible with such an old
> piece of equipment? I'm very familiar with using SCPI commands over telnet
> but not so familiar with HPIB.
> 
> So far I've installed the NI 488.2 software which has successfully found
> both the GPIB-ENET/1000 box and the HP5328A connected to it. I've opened
> the NI-488.2 communicator which should allow me to send commands to the
> counter and read back results. However, anything I type in the "send
> string" returns a timeout.
> 
> The manual for the 5328A shows example commands such as:
> CMD"?U*","T"
> But it's not clear to me what portion (all?) is the string that I should be
> sending to the 5328a.
> 
> The 5328a is set to "Talk Only" mode via dip switch. I would expect that I
> should be able to just 'read' the results, but 'read' also times out...
> 
> Thanks for any pointers,
> James
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Re: [time-nuts] HP5065A Rubidium question

[Scott McGrath]

Get the manual because if it's been off a long time the RB migrates out of the 
reservoir and coats the bulb so light does not escape

There is a built in 'cold trap' which is used to return the Rb to the reservoir 

Using this is version specific and you need a good power supply as you can 
damage the Rb assembly if done incorrectly

Luciano's recommended steps should be checked first though


> On Feb 20, 2017, at 1:47 AM, timeok  wrote:
> 
> 
>   Hi Scott,
>   I have never find a photodiode faulty. When applied 20 volts to the lamp it 
> should come on within about 10 seconds, and the PHOTO I meter on the panel 
> will be between 20 and 50. If this does not happen the most probable failure 
> is the resistance R1 on the lamp board (1330ohm 2W). In this case, I suggest 
> you replace it with two 2700-ohm 1W resistors in parallel.
> 
>   Other faults that I found were: the broken transistor Q1 and the exciter 
> coil detached from one side, but these failure are very rare.
>   let me know,
>   regards,
>   Luciano
> 
>   There is 20 VDC feeding the RVFS lamp oscillator.
> 
>   But, there is no current coming from the photodiode. (Maybe a few picoamps 
> of dark current, certainly not the expected ~50 microamps of DC, and no 
> 137/234 Hz signals).
> 
>   It seems the most likely problem is that the Rb lamp is not coming on. 
> Maybe possible that the photodiode is faulty, or a broken wire, etc.
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Re: [time-nuts] HP 5061A Cesium Beam Std

[Scott McGrath]

For a tube which has not been powered up for a long time it can take days or 
weeks for the ion pump to bring the vacuum back to a normal state.   

Replacement tubes are available but they are breathtakingly expensive on the 
order of 22k 

It's a crapshoot with old Cs tubes but for $400 I'd be inclined to keep it and 
acquire over time the items needed to support it like HVPS etc


Content by Scott
Typos by Siri

> On Feb 9, 2017, at 8:21 PM, David Smith  wrote:
> 
> 
> Hello Time Nuts Friends,
> 
> I have acquired an HP 5061A off of EBAY and I believe the cesium beam tube 
> may be bad. The ion pump meter pins out and never comes down to a reasonable 
> level. I don’t have an external HVPS to check the tube as suggested in the 
> manual. I’m thinking the worst here… that the tube is probably bad. The 
> seller listed it “For Parts” and the usual “I have no way of checking it.” 
> Fortunately, he has a 14 day return policy. He’s offered me $400 to keep it. 
> I have $725 in it.
> 
> My question to the group is… are there replacement tubes available? Any 
> suggestions on what to do with it if I can’t get a replacement tube?
> 
> Thanks in advance,
> 
> Dave Smith / W6TE
> Sent from Mail for Windows 10
> 
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Re: [time-nuts] What to do with a 5061A/5061B with dead NiCds

[Scott McGrath]

I would second the UPS idea in addition to rebuilding the internal pack which I 
see as more of a carryover supply while physically moving the standArd or 
performing maintenance on the line / 24VDC inputs

Content by Scott
Typos by Siri

> On Feb 6, 2017, at 8:50 AM, Scott McGrath <scmcgr...@gmail.com> wrote:
> 
> I went with option #2 and opted for batteries plus to rebuild the packs as I 
> recall it was about 80 dollars to rebuild the pack which included a 1 year 
> warranty
> 
> The problem with moving to lithium batteries is building the battery 
> management system and safety systems needed for the SAFE operation of lithium 
> cells.
> 
> Content by Scott
> Typos by Siri
> 
>> On Feb 5, 2017, at 6:27 PM, Skip Withrow <skip.with...@gmail.com> wrote:
>> 
>> Hello time-nuts,
>> 
>> I have 5061A and 5061B units with the battery option and dead battery
>> packs.  My question is what makes the most sense when refurbing these units?
>> 
>> 1.  Yank the old battery out and just leave it that way.  Running the unit
>> on a UPS would preserve the functionality.
>> 
>> 2. Replace the pack with a rebuilt NiCd pack.  I'm sure Batteries Plus
>> would be happy to do it, but sounds expensive.
>> 
>> 3. Replace the pack with a NiMH pack, and really crank down the float
>> current of the 5061.
>> 
>> 4. Replace the pack with Li-ion battery.  Would be a much smaller battery,
>> but the charging circuit would have to be pitched.  Building in a Li-ion
>> charge controller sounds like it could be a project (which I don't
>> necessarily want).
>> 
>> 5. Yank the old battery pack and run the 5061 on two 12V batteries with an
>> appropriate power supply/charger (basically a version of #1).
>> 
>> Any thoughts on these or other options would be appreciated.  Thanks in
>> advance.
>> 
>> Regards,
>> Skip Withrow
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Re: [time-nuts] What to do with a 5061A/5061B with dead NiCds

[Scott McGrath]

I went with option #2 and opted for batteries plus to rebuild the packs as I 
recall it was about 80 dollars to rebuild the pack which included a 1 year 
warranty

The problem with moving to lithium batteries is building the battery management 
system and safety systems needed for the SAFE operation of lithium cells.

Content by Scott
Typos by Siri

> On Feb 5, 2017, at 6:27 PM, Skip Withrow  wrote:
> 
> Hello time-nuts,
> 
> I have 5061A and 5061B units with the battery option and dead battery
> packs.  My question is what makes the most sense when refurbing these units?
> 
> 1.  Yank the old battery out and just leave it that way.  Running the unit
> on a UPS would preserve the functionality.
> 
> 2. Replace the pack with a rebuilt NiCd pack.  I'm sure Batteries Plus
> would be happy to do it, but sounds expensive.
> 
> 3. Replace the pack with a NiMH pack, and really crank down the float
> current of the 5061.
> 
> 4. Replace the pack with Li-ion battery.  Would be a much smaller battery,
> but the charging circuit would have to be pitched.  Building in a Li-ion
> charge controller sounds like it could be a project (which I don't
> necessarily want).
> 
> 5. Yank the old battery pack and run the 5061 on two 12V batteries with an
> appropriate power supply/charger (basically a version of #1).
> 
> Any thoughts on these or other options would be appreciated.  Thanks in
> advance.
> 
> Regards,
> Skip Withrow
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Re: [time-nuts] Problem with HP 83623A 20 GHz sweep generator stepping up/down 100 Hz when not wanted.

[Scott McGrath]

I think case #1 tells you that the frequency step is not occurring on the 
sweeper as both The source and receiver are locked to GPS and no trace of the 
step effect is seen 

 I would be much more inclined to think that the transverter is encountering 
some type of power supply related artifact.

As to the tuned receiver mode yes it's VERY poorly documented but I use it in 
conjunction with an Anechoic chamber to characterize antennas

> On Dec 22, 2016, at 5:45 PM, Dr. David Kirkby (Kirkby Microwave Ltd) 
> <drkir...@kirkbymicrowave.co.uk> wrote:
> 
>> On 22 December 2016 at 02:54, Scott McGrath <scmcgr...@gmail.com> wrote:
>> 
>> Can you use the VNA as a receiver? And determine whether the 100Hz shift
>> is also seen on the VNA
> 
> The VNA has what's called "tuned receiver" mode, but it is very poorly
> documented - or at least I've never seen it well documented.
> 
> 
> I tried a few different things.
> 
> 1) Put the sweep generator into the VNA using tuned-receiver mode. Both
> were locked to GPS. The signal generator appears in the middle of the
> screen, and whilst one can't say a lot about the quality, there's no doubt
> that the position of the peak never moves `100 Hz.
> 
> 2) Put the signal generator into the spectrum analyzer. This does show some
> odd results sometimes, but I'm always a bit concerned that these might
> internally generated signals, as whatever source on connects to the SA, it
> brings up a lot of spurious signals. There's currently no preselector on
> this, although I do have one in a box.
> 
> But there is some evidence that maybe the oscillator is moving. But I'm not
> 100% convinced.
> 
> 3) Connected the source output of the VNA to the spectrum analyzer. The SA
> shows the source is far from clean - much poorer than the signal
> generator.  So I think I can conclude that the source in the VNA is quite
> poor, which is what I expected to be honest. There is not even a
> specification for phase noise on this.
> 
> So any thoughts of mixing the VNA source with the signal generator will be
> a complete waste of time.
> 
> I think I can conclude that attempting to use the VNA in any source of
> measurement or as a signal source will just not work.
> 
> 
> Dave
> 
> 
> 
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Re: [time-nuts] Problem with HP 83623A 20 GHz sweep generator stepping up/down 100 Hz when not wanted.

[Scott McGrath]

Can you use the VNA as a receiver? And determine whether the 100Hz shift is 
also seen on the VNA

> On Dec 21, 2016, at 7:31 PM, Dr. David Kirkby (Kirkby Microwave Ltd) 
>  wrote:
> 
> On 21 December 2016 at 23:42, Dr. David Kirkby (Kirkby Microwave Ltd) <
> drkir...@kirkbymicrowave.co.uk> wrote:
> 
> 
>> But one thing to possibly is
>> 
>> * Set sweep generator to 10.368 GHz
>> * Set sweep generator to 10.378 GHz, so there's a 10 MHz difference.
> 
> 
> I mean set the VNA to  10.378 GHz, so there's a 10 MHz difference between
> the VNA and sweep generator.
> 
> Dave
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Re: [time-nuts] precision timing pulse

[Scott McGrath]

You could build a simple one shot using something like a 555 timer IC 

Or take a input pin from your PiC and use the RTC to drive a routine which 
changes state of the pin for the duration of test

Content by Scott
Typos by Siri

> On Nov 15, 2016, at 1:57 PM, Chuck / Judy Burch  
> wrote:
> 
> 
> I'm building a laboratory scintillation counter that uses my HP 5335a counter 
> as a read-out.  The FREQ mode gives only approximate results (maximum gate 
> time is about 5 seconds).  The TOT mode counts pulses for an arbitrary time 
> that can be set using the "external arm input" on the rear panel.  So I need 
> a timing pulse (of either polarity) of known and adjustable width (time).  
> One way to do this is with a PIC frequency divider taking the counter 10MHz 
> output down to 1 PPS following that with two or three ripple counters to get 
> a 1 - 5 - 10 - 50 ... sequence.  That I understand.
> 
> How do I get a pulse to start with a push button and then stop for example 
> 500 or 10,000 seconds later?
> 
> 
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Re: [time-nuts] Swagelok and metric tubing question

[Scott McGrath]

Hi Corby

Is there a requirement for a specific alloy?   I might have some odds and ends 
lying around 

Content by Scott
Typos by Siri

> On Nov 11, 2016, at 12:51 PM,   wrote:
> 
> This sound off topic but it's for a Hydrogen Maser modification!
> The EFOS2 Maser is running low on Hydrogen and this time rather than
> refill the compressed gas bottle I'd like to install a Hydrostik in its
> place.
> I have obtained all the fittings I need but have hit a snag!
> I need a few short pieces of 10mm OD 1 or 2mm  wall stainless tubing to
> go into the Metric Swagelok fitting.
> However all I can find on the net would cost me over $100.00!
> Does anybody have a few short lengths (two 3" and two 4" if cut ready to
> insert in the fitting) or one 18" piece that I could buy at a reasonable
> price???
> 
> Thanks,
> 
> Corby
> 
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Re: [time-nuts] 5071A with ATTENTION flashing

[Scott McGrath]

that's telling you that the CBT oven is not up to temp  so you could have a 
failed heater in the tube or the oven controller is malfunctioning 

The former well you need a new tube which symmetricom will be happy to sell you 
for a 5 figure price tag.

The latter is limited by your repair skills and parts and data availability

Content by Scott
Typos by Siri

> On Nov 9, 2016, at 7:42 AM, Li Ang <379...@qq.com> wrote:
> 
> According to the Log, "CBT Oven Err: -9.55 C" might be something wrong. 
> However, I can't find the correct range in the manual. Does anyone have the 
> information about this parameter?
> 
> 
> Regards
> Li Ang
> 
> 
> 
> 
> -- Original --
> From:  "Li Ang";<379...@qq.com>;
> Date:  Wed, Nov 9, 2016 02:48 PM
> To:  "Tom Van Baak"; "Discussion of precise time and 
> frequency measurement"; 
> 
> Subject:  Re: [time-nuts] 5071A with ATTENTION flashing
> 
> 
> 
> Hi Tom
> 
> I have collected the log from it. Log level is service. The 9.2G pll pass the 
> test today. The log during the power-up process is also included.
> 
> 
> Regards
> 
> Li Ang / BI7LNQ
> 
> -
> 
> 
> 
> scpi >
> 
> MJD0 02:02:18
> 
> CBT ID: 3128A00642(H)
> 
> Status summary: Fatal Error (see Log)
> 
> Power source: AC
> 
> Log status: One entry
> 
> 
> Freq Offset:  0e-15  Osc. control: -9.56 %
> 
> RF amplitude 1: 6.3 %RF amplitude 2: 6.3 %
> 
> Zeeman Freq:  39949 Hz   C-field curr:12.213 mA
> 
> E-multiplier:  2553 VSignal Gain:   14.4 %
> 
> 
> CBT Oven:   0.0 VCBT Oven Err: -9.55 C
> 
> Osc. Oven: -9.1 VIon Pump:   0.4 uA
> 
> HW Ionizer:-0.1 VMass spec:12.3 V
> 
> SAW Tuning: 0.0 VDRO Tuning: 7.3 V
> 
> 87MHz PLL:  0.8 VuP Clock PLL:   1.8 V
> 
> +12V supply:   12.3 V-12V supply:  -12.3 V
> 
> +5V  supply:5.4 VThermometer:   46.2 C
> 
> 
> 
> scpi >
> 
> scpi > ?
> 
> E-103> exit
> 
> E-113>
> 
> E-113> Log status: One entry
> 
> 
> Log 000 of MJD0 00:12:40:  Low Cs signal (60) with max Emult
> 
> 
> PASS: CBT register test
> 
> PASS: CBT window comp test
> 
> PASS: CBT therm test
> 
> PASS: CBT Cs oven test
> 
> PASS: CBT hw ion test
> 
> PASS: CBT mass spec test
> 
> PASS: CPU RTDS test
> 
> PASS: CPU clock locked test
> 
> PASS: DDFS register test
> 
> PASS: 87MHz PLL test
> 
> PASS: 9.2 GHz PLL test
> 
> PASS: Servo register test
> 
> PASS: Servo convertor timeout test
> 
> PASS: Interface register test
> 
> PASS: Interface abus test
> 
> PASS: Pps register test
> 
> PASS: Pps interrupt test
> 
> PASS: power logic signals test
> 
> PASS: CBT register test
> 
> PASS: CBT window comp test
> 
> PASS: CBT therm test
> 
> PASS: CBT Cs oven test
> 
> PASS: CBT hw ion test
> 
> PASS: CBT mass spec test
> 
> PASS: CPU RTDS test
> 
> PASS: CPU clock locked test
> 
> PASS: DDFS register test
> 
> PASS: 87MHz PLL test
> 
> PASS: 9.2 GHz PLL test
> 
> PASS: Servo register test
> 
> PASS: Servo convertor timeout test
> 
> PASS: Interface register test
> 
> PASS: Interface abus test
> 
> PASS: Pps register test
> 
> PASS: Pps interrupt test
> 
> PASS: power logic signals test
> 
> PASS: CBT register test
> 
> PASS: CBT window comp test
> 
> PASS: CBT therm test
> 
> PASS: CBT Cs oven test
> 
> PASS: CBT hw ion test
> 
> PASS: CBT mass spec test
> 
> PASS: CPU RTDS test
> 
> PASS: CPU clock locked test
> 
> PASS: DDFS register test
> 
> PASS: 87MHz PLL test
> 
> PASS: 9.2 GHz PLL test
> 
> PASS: Servo register test
> 
> PASS: Servo convertor timeout test
> 
> PASS: Interface register test
> 
> PASS: Interface abus test
> 
> PASS: Pps register test
> 
> PASS: Pps interrupt test
> 
> PASS: power logic signals test
> 
> PASS: CBT register test
> 
> PASS: CBT window comp test
> 
> PASS: CBT therm test
> 
> PASS: CBT Cs oven test
> 
> PASS: CBT hw ion test
> 
> 
> E-113>
> 
> E-113> PASS: CBT register test
> 
> PASS: CBT window comp test
> 
> PASS: CBT therm test
> 
> PASS: CBT Cs oven test
> 
> PASS: CBT hw ion test
> 
> PASS: CBT mass spec test
> 
> PASS: CPU RTDS test
> 
> PASS: CPU clock locked test
> 
> PASS: DDFS register test
> 
> PASS: 87MHz PLL test
> 
> PASS: 9.2 GHz PLL test
> 
> PASS: Servo register test
> 
> PASS: Servo convertor timeout test
> 
> PASS: Interface register test
> 
> PASS: Interface abus test
> 
> PASS: Pps register test
> 
> PASS: Pps interrupt test
> 
> PASS: power logic signals test
> 
> PASS: CBT register test
> 
> PASS: CBT window comp test
> 
> PASS: CBT therm test
> 
> PASS: CBT Cs oven test
> 
> PASS: CBT hw ion test
> 
> PASS: CBT mass spec test
> 
> PASS: CPU RTDS test
> 
> PASS: CPU clock locked test
> 
> PASS: DDFS register test
> 
> PASS: 87MHz PLL test
> 
> PASS: 9.2 GHz PLL test
> 
> PASS: Servo register test
> 
> PASS: Servo convertor timeout test
> 
> PASS: Interface register test
> 
> PASS: 

Re: [time-nuts] Temp/Humidity control systems?

[Scott McGrath]

Personally I'd be looking at a commercial ductless heat pump unit Mitsubishi 
MrSlim comes to mind in your case you would want a 'cartridge' type unit 
designed for ceiling mount the ones for data center use have humidity control 
as well.   Figure these units will hold +/- 2-3 deg F over long term

If you really want to go over the top get a used RF shield room.  Lots of used 
ones coming on market as stuff is going over 26Ghz.  Shipping will be the ugly 
bit as the doors are heavy

Content by Scott
Typos by Siri

> On Oct 26, 2016, at 1:58 PM, John Ackermann N8UR  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] COTS cesium standard physics package life

[Scott McGrath]

It depends on the beam tube   There is a fixed amount of Cs in any given beam 
tube this pool of Cs is consumed during operation.Once the Cs is depleted 
the tube will no longer function.It's possible with intermittent use for 
the tube to run for decades as long as vacuum maintenance is performed.   Most 
Cs tubes have a published expected lifetime before replacement is required  
while maintaining published specifications.   It's possible to extend tube life 
somewhat by increasing oven temp and electrode voltages but the signal becomes 
noisier as a result

Content by Scott
Typos by Siri

> On Sep 29, 2016, at 8:07 AM, Ruslan Nabioullin  wrote:
> 
> Hi, I'm unable to fully grasp the lifetime specifications of typical COTS 
> cesium standard physics packages, for both old and new designs. For example, 
> the documentation of an older HP standard specifies a shelf life of two years 
> if the ion pump is operated two or three times per year, yet at the same time 
> the ``beam tube warranty'' period is three years.  Does this mean that if the 
> physics package is fully operating (i.e., LOOP OPEN, OPER, or LTC), then it's 
> guaranteed to last at least three years, but if it's completely shut down, 
> except for vacuum maintenance sessions (using the mode CS OFF) two or three 
> times per year, it will last only two years?  Also, what will the expected 
> lifetime of the package be if the standard is kept as a reserve, 
> specifically, continuously-powered with the mode set to CS OFF (so continuous 
> vacuum maintenance), and activated or deactivated to or from, resp., OPER, as 
> needed, excl. the time spent fully operating (i.e., in this case, the time 
> spent in th
 e OPER mode doesn't count)?
> 
> Thanks in advance,
> Ruslan
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Re: [time-nuts] HP 105B Battery the saga continues

[Scott McGrath]

That NiCad pack is part of the power supply and as Jeremy points out is part of 
the filter system.And so one needs to restore it as part of the instrument 
as even the 28V external power supply floats these cells and trips power 
interruption indicator if lost



Power supply is not terribly hard to fix and the small signal transistors can 
be replaced with  2N ,3904 and 3906'es depending on rating.  You don't even 
need a extender a Huntron tracker or similar current limited lissajous bridge 
will identify failed or leaky caps and semiconductors 

Remember HP did nothing without a good engineering reason and that plate is 
there for RF shielding to prevent stray sources coupling with the outputs

If a proper rebuild is too expensive I'd suggest selling it on the well known 
auction site rather than hacking it up as 105's have been selling in the 
hundreds regardless of condition 


> On Sep 17, 2016, at 10:16 PM, Jeremy Nichols  wrote:
> 
> How did you come up with the 33,000 uF number, Perry, and is it one big 
> capacitor or lots of little ones tied together? The big cap will also filter 
> out some of the remaining ripple in the power supply that may have been 
> managed by the ni-cad battery.
> 
> Jeremy
> 
> 
>> On 9/17/2016 3:50 PM, Perry Sandeen via time-nuts wrote:
>> 
>>  Where the nicad pack was located one can put in 33,000 uF of Nichicon 105C 
>> caps for $20 for a buffer hold over. 
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Re: [time-nuts] HP-105B Battery Replacement?

[Scott McGrath]

Actually the larger SmartUPS series can run for hours providing a large enough 
battery string is available I have a SmartUPS RM3000 running data rack this 
has 2 external battery boxes and will run everything for 6 hours.


For TimeNuts applications though I'd recommend a Liebert UPS as this is a 
'online' UPS as in input is converted to DC and used to float batteries and 
drive a power oscillator for a true sine output and in a power interruption 
there is no transfer time or transients on the output

Content by Scott
Typos by Siri

> On Sep 16, 2016, at 3:50 AM, Hal Murray  wrote:
> 
> 
> g...@rellim.com said:
>> APC UPS can't handle the longer runtime, but never had a problem with any
>> version of CyberPower.
> 
> There are two parameters for UPS boxes.  One is the power the electronics can 
> handle.  The other is the amount of energy the batteries can hold.
> 
> I think some of the smaller units have inadequate cooling to run at rated 
> power for long, but their batteries are small enough so that they run out of 
> power before the electronics overheats.
> 
> -- 
> These are my opinions.  I hate spam.
> 
> 
> 
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Re: [time-nuts] HP-105B Battery Replacement?

[Scott McGrath]

I had my local BatteriesPlus rebuild my pack for my 105B about 4 years ago and 
it's still working well as I recall the cost was about 175. But I specified use 
best quality cells.  Plus they have the proper battery welder and test gear and 
they have more vendor clout to get consistently good cells as opposed to 
getting them mail order or through the well known auction sites

Content by Scott
Typos by Siri

> On Sep 15, 2016, at 1:16 PM, paul swed  wrote:
> 
> Brookes comments are the facts you can not use simple charging circuits.
> But smart charging circuits seem to be available on various sites for low
> cost. It seems the RC modelers have helped us out.
> The thing I will say is I have ordered new nicad C cell batteries from
> major a major vendor and they did not last long at all for the cost I was
> quite disappointed.
> Regards
> Paul
> WB8TSL
> 
>> On Thu, Sep 15, 2016 at 12:59 PM, Brooke Clarke  wrote:
>> 
>> Hi Jeremy:
>> 
>> I'm currently having fun playing with various rechargeable battery related
>> stuff  which includes Li-Ion cells.
>> http://www.prc68.com/I/BatTst.shtml#Resistor
>> The cells come in three configurations:
>> 1. the raw flat top cell with optional tabs to allow easy soldering into a
>> pack,
>> 2. cell plus positive button cap which includes a Positive Temperature
>> Coefficient (PTC) fuse and an over pressure vent,
>> 3. fully protected, like 2, plus circuit that turns off the battery if
>> charging and over voltage or loaded and under voltage.  On these you can
>> feel a wire/ribbon running from positive to negative under the shrink wrap
>> and they are slightly longer.
>> These configurations are independent of the flavor of Li chemistry.
>> 
>> To go with any of the above you need a charger specific to the particular
>> Li chemistry (the charging voltage is not the same) and if a pack you also
>> need a either cells like 3 above or a protection circuit for the pack.  For
>> optimum performance in addition a tap between each virtual cell (made of of
>> parallel cells) so that the charge can be balanced and a charger that can
>> do that.  This is not easy, witness the current recall of the Galaxy Note
>> 7s phones.
>> 
>> I would just use modern Ni-Cad cells mainly because of the ease of
>> charging and maintaining them and use the existing charging circuitry.
>> Li chemistry has advantages for portable equipment, but not so much for
>> rack mounted equipment.
>> 
>> --
>> Have Fun,
>> 
>> Brooke Clarke
>> http://www.PRC68.com
>> http://www.end2partygovernment.com/2012Issues.html
>> The lesser of evils is still evil.
>> 
>>  Original Message 
>> 
>>> Thanks, Brooke, I'll price new Ni-Cads. I wasn't thinking of lead-acid
>>> (gel
>>> cells) but rather lithium rechargeable, providing I can find a type that
>>> won't catch fire and will work with the 105B'scircuits.
>>> 
>>> Jeremy
>>> 
>>> 
>>> On Wednesday, September 14, 2016, Brooke Clarke 
>>> wrote:
>>> 
>>> Hi Alex:
 
 Yes, I'm recommending Ni-Cad but NOT any acid type.
 
 --
 Have Fun,
 
 Brooke Clarke
 http://www.PRC68.com
 http://www.end2partygovernment.com/2012Issues.html
 The lesser of evils is still evil.
 
  Original Message 
 
 Hi Brooke,
> 
> sorry I have to disappoint you; Ni-Cd batteries do not use any acid,
> they
> have K-OH  kalium hidrioxid  [potassium hydroxide  for anglophone ] as
> electrolyte and they are normally very air-tide, and widely used in
> radios.
> 
> 73
> 
> KJ6UHN
> 
> Alex
> 
> On 9/14/2016 4:45 PM, Brooke Clarke wrote:
> 
> Hi Jeremy:
>> 
>> It's a very bad idea to put any battery with acid in an enclosure that
>> has electronics since if it vents the acid will etch the PCBs.
>> Guess how I learned this.  I got a great price on a Gibbs Frequency
>> Standard because the oven no longer worked.
>> http://prc68.com/I/office_equip.html
>> 
>> 
>> Modern Ni-Cad batteries have much more capacity than older ones and no
>> longer have a memory effect.  They are also very easy to charge, so
>> why not
>> just replace the old cells?
>> 
>> 
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Re: [time-nuts] Working with SMT parts.

[Scott McGrath]

Yes however since you are simply submitting the circuit design it makes sense 
that they would hold the Gerber until you bought prototypes as unless you have 
software to create the Gerber it has value as once you have the Gerber you can 
have the boards built anywhere.They need to make a profit to stay in 
business after all

Content by Scott
Typos by Siri

> On Aug 11, 2016, at 11:45 PM, Chris Albertson  
> wrote:
> 
> This seems totally backwards.  Typically a Gerber file is something
> you make yourself on your computer then send it in for a prototype.
> Seems odd to buy them.
> 
> I checked ExpressPCB prices and they are very high.  I can get PCBs
> made quickly in the US for $3 per square inch, shipping included with
> $9 minimum order.  And  you don't buy the Gerbers.
> 
> I notice ExpressPCB offers free software.  But it is totally
> non-standard and you can't use it for anything other then for their
> service.  Most people needing free PCB software use Eagle, some use
> Kicad or some others.  But Eagle seems to be kind of a universal
> standard.
> 
> 
> 
> 
>> On Thu, Aug 11, 2016 at 8:55 AM, Didier Juges  wrote:
>> I concur. I have been using ExpressPCB extensively over the last 2 years
>> with great satisfaction now that it is possible to get Gerber files from
>> them.
>> I typically use the mini board pro service (3 bare boards, 2 sided with
>> solder mask and silk screen) for prototypes and then buy the Gerbers
> 
> -- 
> 
> Chris Albertson
> Redondo Beach, California
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Re: [time-nuts] Safely getting the electrical length of a connected antenna feedline

[Scott McGrath]

Because Velocity Factor determines the time it takes a EM wave to traverse the 
cable it ALSO shortens the wavelength by the same amount relative to free space 
this is why coaxial cables can be used as delay lines and why when cutting 
resonant sections of coaxial cable the Velocity Factor must be known

Content by Scott
Typos by Siri

> On Aug 11, 2016, at 2:56 PM, Bob Stewart  wrote:
> 
> Why is velocity factor an issue?  Aren't we only interested in the electrical 
> time from one end of the coax to the other?
> Bob
>  -
> AE6RV.com
> 
> GFS GPSDO list:
> groups.yahoo.com/neo/groups/GFS-GPSDOs/info
> 
>  From: Didier Juges 
> To: Bob Albert ; Discussion of precise time and frequency 
> measurement  
> Sent: Thursday, August 11, 2016 1:20 PM
> Subject: Re: [time-nuts] Safely getting the electrical length of a connected 
> antenna feedline
> 
> I used the PPS from a Thunderbolt (fast rise lime, low rep frequency, was 
> handy) and a digital storage scope and a couple of resistors to make a 
> reflectometer based on this experiment:
> 
> www.ko4bb.com/getsimple/index.php?I'd=coax-cable-impedance-matching
> 
> You can very clearly see a 50 ohm/75 ohm mismatch.
> 
> The biggest variable will be the velocity factor.
> 
> Didier KO4BB
> 
> 
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Re: [time-nuts] Using the HP 58503a to correct your PC clock

[Scott McGrath]

Because people have been trained by marketeers to look for the 'silver bullet'  
 But there are generally only a few methods to accomplish a given task 

Heck look at the 'cloud' those of us who were using large scale computers in 
the 80's called it 'timesharing'  and the most important app on the PC at the 
time was a vt100 or 3270 emulator and graphics were done on a Tek vector 
terminal

Content by Scott
Typos by Siri

> On Aug 4, 2016, at 9:39 PM, Chris Albertson  wrote:
> 
> I always wonder why people try all kinds of solutions when there are two
> known to work as well as theoretically possible.
> 
> There is NTP and PTP.
> 
> NTP was released to the world in 1985, about 30 years ago.  The algorithm
> has been in peer reviewed papers and the source code gets reviewed
> continuously by experts in the field and when one of them finds a problem
> solutions are discussed and corrections are made.  After 30 years of
> continuous review and revision it is close to as good as it will get.
> (except for possible security issues in the implementation)  There is a
> very active community of academics and computer scientists that keep NTP up
> to date.Its problem is that it is designed to work over a public
> network that the user has no control over so the assumption must be made
> that the network equipment has only some minimum features.  NTP's accuracy
> tops out (with great effort) at about 1 microsecond but typically 1
> millisecond
> 
> PTP on the other hand is designed to do about the same as NTP but over a
> local network the user has complete control over and requires specialized
> networking equipment.  PTP accuracy routinely breaks 1uSec but can't work
> so well over a public Internet.
> 
> If these two where not free, easy to set up and well supported then it
> might be worth looking for something else.
> 
> From a "Time Nuts" point of view none of the above are even close to
> accurate clocks.  A microsecond is a very course and crude measure of
> time.  Pico and Femto seconds are were it gets interesting.
> 
> Maybe someday NTP will have a time nuts level of accuracy.  the new up
> coming version, I hear will be using 64 bits to carry the factional part of
> a second.  That is truly nuts.
> 
> Yes, there is room for more software if maybe one needs to transform time
> under conditions not covered by NTP or PTP or needs to do much better than
> 1uSec.  But typically when that happens we resort to hardware solutions
> like 1PPS distributions and/or 10MHz distortions or common view of GPS
> carriers signals.  Packetized network just don't work if you need to be
> much better than 1uSec.
> 
>> On Thu, Aug 4, 2016 at 11:47 AM, David  wrote:
>> 
>> The old Tardis program for Windows (Tardis2000 now) handles it
>> correctly by altering the rate and only jamming the time if it is
>> outside of a specified window but I do not think its GPS mode supports
>> the 1 PPS signal.
>> 
>> I am not sure if Tardis works with Windows 7 and above though; I
>> forget to test it on my Windows 7 test system when I had it.  It is a
>> pretty old (but free) program.
>> 
>>> On Tue, 2 Aug 2016 23:28:06 -0700, you wrote:
>>> 
>>> The WRONG way to adjust a PC clock is to set the TIME periodically from
>>> some standard.  When you do this then the time on the PC is not running at
>>> a constant rate.  The correct way to do this is to adjust the PC's clocks
>>> RATE.  You make it runs slightly faster if you notice it is getting behind
>>> and slightly slower if it is running fast.
>>> 
>>> Think about what you would do to a real physical clock.  You would not set
>>> it every few minutes, you'd adjust the rate and wait a little while to see
>>> if the adjustment needs refinement or not.
>>> 
>>> ...
>>> 
>>> Most operating systems in use today run NTP to keep their clocks in order.
>>> Well most OSes except for Windows.  Microsoft uses a vey much simplified
>>> version of this that does the wrong thing and periodically sets the PC's
>>> clock.   You could enable this and likely, maybe reach your +/- 100ms
>> goal.
>>> Not the "real" NTP is a free program and not hard to set up so you can
>>> have 1ms level accuracy without much effort and better with some work.
>>> 
 On Tue, Aug 2, 2016 at 8:13 PM, Ron Ott  wrote:
 
 This has probably been covered in the past, but is there a way correct
>> or
 control a PC (Windows 7) clock with the HP 58503A GPS receiver? I just
 bought one (on the way now) and have a copy of satstats50 on hand. I've
 been using Dimension 4 and I'm surprised at the size of correction every
 couple minutes to my PC clock.  I'd be happy if my PC clock were
>> accurate
 to plus/minus 100ms.
 Ron
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Re: [time-nuts] The home time-lab

[Scott McGrath]

Charles is correct and most data centers and metrology laboratories operate 
from power produced by large versions of these systems i.e. From 50KW to 
megawatts generally backed by one or more generators to carry facility when 
utility power is not available 

Content by Scott
Typos by Siri

> On Jul 25, 2016, at 8:39 AM, Charles Steinmetz  wrote:
> 
> Chris wrote:
> 
>> I've never thought UPS were a good idea for anything but a computer
>> that needs to shut down gracefully.   For your use you need something
>> that cleans up the AC mains power.
> 
> A proper "online" (or "double conversion") UPS does just that.  It always 
> provides cleanly-generated sine-wave power from a DC-AC converter.  Most will 
> even deliver crystal-controlled power (i.e., non-synchronous with the AC 
> line) in several frequency increments, if you desire, as well as a choice of 
> regulated output voltages.  (For obvious reasons, they are usually operated 
> synchronously.)
> 
> They are *much* more effective than ferroresonant supplies at removing 
> glitches from the mains supply.
> 
> You must be referring to "offline" backup supplies.
> 
> Best regards,
> 
> Charles
> 
> 
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Re: [time-nuts] GPS disciplined Mars clock

[Scott McGrath]

The Venusian's are feeling left out 

Content by Scott
Typos by Siri

> On Jul 9, 2016, at 2:58 AM, Mark Sims  wrote:
> 
> To appease our new (hopefully) benevolent Martian overlords,  Lady Heather 
> can now work in Mars time...   and I have it running right now while 
> connected to a Jupiter timing receiver.
> 
> -
>> Hmm. I have a SC-01.. One could hook it up to a Arduino trivially.
> And run it on Mars time.. 
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Re: [time-nuts] The home time-lab

[Scott McGrath]

Best bet is to get 4 6v deep cycle batteries connect in series and connect a 
high quality power supply capable of supporting planned load and set output 
voltage to the selected 'float' voltage This will give you a setup which 
depending on batter rating could give you several days of backup power

Content by Scott
Typos by Siri

> On Jul 8, 2016, at 12:53 PM, Wes  wrote:
> 
> I have for years powered much of my ham station with a 90AH SLA maintained 
> with a homemade "smart" charger. I used an analog Astron 35A power supply 
> (RS-35M) for its raw DC and series pass transistors with its regulator board 
> replaced with a (now obsolete) AA Engineering smart charger board.  This used 
> a uC3906 IC for control.  Capacity wise this was actually overkill for my 
> application as the charger could supply the total load.
> 
> Although many years ago I worked for the founders of Iota Engineering I have 
> no interest in the company other than as a satisfied customer.  That said, if 
> someone wants to pursue something similar I can recommend their power 
> supplies with their "smart charger" modules.  
> (http://iotaengineering.com/power.htm)
> 
> 
>> On 7/8/2016 12:08 AM, Hal Murray wrote:
>> i...@blackmountainforge.com said:
>>> There is a company in the USA that manufactures a product called
>>> BatteryTender - excellent float charger and maintainer. Costco sells them
>>> for $40
>> How do those types of chargers work when there is a load?
>> 
>> It's not the typical "float" there is also significant current going to the
>> thunderbolt.
> 
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Re: [time-nuts] Heliostat

[Scott McGrath]

Hi Brooke

Primary use of heliostats in astronomy is solar observation 

Content by Scott
Typos by Siri

> On Jul 2, 2016, at 3:12 PM, Brooke Clarke  wrote:
> 
> Hi:
> 
> I recently got an Eastern Science Supply Co. demonstration heliostat, that's 
> to say it's small enough to easily hand hold. I've go it working but have 
> some questions.
> Based on some Waterbury Clock Co. patents I think is was made in the late 
> 1920s or early 1930s.  ESSCo was into astronomy.  I got a book they published 
> "A Manual of Laboratory Astronomy, for use in introductory courses by Harlan 
> True Stetson Phd, 1928 - but no mention of the heliostat.
> http://www.prc68.com/I/ESSCoHeliostat.html
> 
> The base has level vials and an elevation scale for the clockwork driven 
> lower mirror that's clearly calibrated in latitude.  The lower (clockwork 
> driven) mirror has a pointer to a scale divided into 24 hours, one half black 
> and the other half white.
> 
> I'm guessing that in order to properly setup this heliostat you need to know 
> the local mean solar time, i.e. correct for Daylight savings, EOT and your 
> offset from the time zone meridian.  That way you could preset the time then 
> rotate the base and tilt the lower mirror until the sun's image was centered 
> on the top mirror.  For now I sort of pointed it at north and adjusted both 
> the lower mirror tilt and the time setting to get the sun along the axis of 
> rotation.
> 
> Were heliostats also used for looking at stars?  i.e. could the Fast-Slow 
> clock adjustment be used to make the clock work for either solar or sidereal 
> time?
> 
> -- 
> Have Fun,
> 
> Brooke Clarke
> http://www.PRC68.com
> http://www.end2partygovernment.com/2012Issues.html
> The lesser of evils is still evil.
> 
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Re: [time-nuts] Cable length calibration

[Scott McGrath]

This is highly dependent on the TDR especially ones designed for long twisted 
pair runs where a high voltage pulse is used to overcome resistive losses

Content by Scott
Typos by Siri

> On Jun 30, 2016, at 10:59 AM, David  wrote:
> 
> The Tektronix 1502 uses a tunnel diode pulser to produce a 50
> picosecond output step of about 200 millivolts.  There is a misprint
> in the theory section of the service manual which says "400 V" instead
> of "400mV".
> 
>> On Thu, 30 Jun 2016 04:19:43 -0400, you wrote:
>> 
>> If the nominal velocity of propagation is known and length is known delay is 
>> easily determined mathematically 
>> 
>> Time Domain Reflectrometry is the usual technique for finding cable length 
>> but even there the cables NVP is an essential parameter if you want to 
>> compute length but not essential in time nuts application because we are 
>> interested in delay which a TDR reads directly When using a TDR its best if 
>> cable is unterminated as the discontinuity at the end is helpful as a 
>> marker.   Also most TDRs like the Tek 1502 can put 100v or more on the cable 
>> which will blow most GPS antennas
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Re: [time-nuts] Cable length calibration

[Scott McGrath]

I'd say it depends on the Time Nut .  NVP X Distance will get you close and 
for a beginning time nut is a worthwhile exercise 

To improve delay calculations now you need instrumentation that not all 
especially beginning time nuts own.I've got a 20 Ghz Agilent scope/TDR 
along with a 110 Ghz network analyzer and just putting a cable on the network 
analyzer and handling it you can see the characteristics changeSo yes you 
are correct that the simple NVPxDistance is not suitable for advanced time 
nuttery.   In fact the delay will change with temperature and barometric 
pressure unless you are using hardline and that's subject to humidity unless 
filled with dry nitrogen under pressure.

Content by Scott
Typos by Siri

> On Jun 30, 2016, at 5:03 PM, Dr. David Kirkby (Kirkby Microwave Ltd) 
> <drkir...@kirkbymicrowave.co.uk> wrote:
> 
>> On 30 June 2016 at 09:19, Scott McGrath <scmcgr...@gmail.com> wrote:
>> 
>> If the nominal velocity of propagation is known and length is known delay
>> is easily determined mathematically
> 
> Except that coax does not have a uniform impedance or velocity factor. Both
> will vary as a function of position and frequency. How relevant this is
> depends on the accuracy you require, but since it is time-nuts, it is
> reasonable to assume that such a simplistic method is not of the standard
> expected on time-nuts.
> 
> Dave
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Re: [time-nuts] Cable length calibration

[Scott McGrath]

If the nominal velocity of propagation is known and length is known delay is 
easily determined mathematically 

Time Domain Reflectrometry is the usual technique for finding cable length but 
even there the cables NVP is an essential parameter if you want to compute 
length but not essential in time nuts application because we are interested in 
delay which a TDR reads directly When using a TDR its best if cable is 
unterminated as the discontinuity at the end is helpful as a marker.   Also 
most TDRs like the Tek 1502 can put 100v or more on the cable which will blow 
most GPS antennas


> On Jun 29, 2016, at 4:08 PM, Brooke Clarke  wrote:
> 
> Hi Hal:
> 
> I think the cal process is essentially a time domain reflection measure of 
> cable length.  The GPS receiver and the cable cal hardware would be in the 
> antenna unit.
> The 1 PPS signal would be aligned at the output of the cable.
> 
> -- 
> Have Fun,
> 
> Brooke Clarke
> http://www.PRC68.com
> http://www.end2partygovernment.com/2012Issues.html
> The lesser of evils is still evil.
> 
>  Original Message 
>> bro...@pacific.net said:
>>> At one point they were looking into making a GPS time receiver where the
>>> cable length calibration would be built-in.
>> How would you do that?
>> 
>> The obvious way is to compare the time you get with a known-good time, but if
>> you had that, why would you want this new GPS with an unknown cable length.
>> 
>> You might be able to do it by measuring the DC drop.  Getting enough accuracy
>> seems tough.
> 
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[time-nuts] GPS NOTAMS issued for US west coast

[Scott McGrath]

All

Check the GPS NOTAMs for the west coast apparently USG will be conducting GPS 
interference testing at  NAS China Lake with a radius of 300NM

Advisory states GPS unavailable for up to 6 hours at a time

>From 6 June to 9 June 

Sorry on a phone or would have copied NOTAM text


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Re: [time-nuts] does anybody have software for the DeLorme LT-20 Earthmate?

[Scott McGrath]

I think they speak NMEA 0183 hook one up to the serial port and try 4800,8,1,N 
and look for the NMEA messages scrolling past.  Play with the serial parameters 



> On Jun 6, 2016, at 12:14 PM, walter shawlee 2  wrote:
> 
> sadly, all the repositories of software for these nice little yellow USB GPS 
> pucks
> has vanished, and nothing remains at the DeLorme site at all. from what I see,
> they discontinued all support after XP.
> 
> if anybody has anything left for them, even a manual PDF file, it would be 
> greatly appreciated,
> I just got them in a bag, with nothing. generic operation under Linux 
> (Ubuntu) would be an especially great find, although I know the company did 
> not produce anything.  I have seen references to some
> later software (also vanished) that was 3rd party.  do any internals for 
> these exist? I can tell from
> the LED codes the ones I have work and can acquire, but I can't get at the 
> data.  I am also curious
> if they can be hacked for time or frequency references as well.
> 
> any information appreciated. I am happy to send a puck to anybody that can 
> come up with working
> linux software!
> 
> all the best,
> walter
> 
> -- 
> Walter Shawlee 2, President
> Sphere Research Corporation
> 3394 Sunnyside Rd.,  West Kelowna,  BC
> V1Z 2V4  CANADA  Phone: (250) 769-1834
> walt...@sphere.bc.ca
> WS2: We're all in one boat, no matter how it looks to you.
> Love is all you need. (John Lennon)
> But, that doesn't mean other things don't come in handy. (WS2)
> 
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Re: [time-nuts] Fw: Optical transfer of time and frequency

[Scott McGrath]

I seem to recall that NASA used optical inferiometry at LC39 for time transfer 
during the shuttle program for the DSN the inferiometry was used to normalize 
the delays in the fiber distribution system caused by temperature and gravity 



> On May 5, 2016, at 2:44 PM, Tom Van Baak  wrote:
> 
> Hi Mark,
> 
>> Interesting... what happened on day 4 to send them all bonkers?
> 
> What you see as bonkers starting the 5th day is actually normal behavior for 
> a cesium clock (or any clock, for that matter). I mention this plot because 
> it shows that you cannot get 500 ps over a day, even with a 5071A -- which is 
> why we're all trying to help the OP with alternative methods of time 
> synchronization.
> 
> There are several ways to plot phase data. What people often do is plot 
> residuals for the entire data set. That is, showing how good the clock would 
> have kept time *if you knew ahead of time what the rate would be*. The first 
> 5 days of the plot shows the residuals based on 5 days of rate fitting. At 
> that point the calculated rate was fixed and the clocks continued to tick. So 
> it becomes a 10-day plot of phase residuals based on 5 days of fitting. I 
> like this because it more dramatically shows how hard it is to keep accurate 
> time.
> 
> The spread in phase is expected. In fact this spread is what ADEV measures; 
> variations in frequency accumulate to phase drift. Or vice versa: erratic 
> drift in phase is evidence of frequency instability, which in turn is 
> summarized with ADEV statistics. I know I'm not explaining this well enough, 
> and it's a bit off-topic for this thread, but I'll write it up later and post 
> it.
> 
> /tvb
> 
> 
> - Original Message - 
> From: "Mark Sims" 
> To: 
> Sent: Wednesday, May 04, 2016 4:41 PM
> Subject: [time-nuts] Fw: Optical transfer of time and frequency
> 
> 
>>> See www.leapsecond.com/tmp/5071a-12-run8-5d-10d.gif for a plot of a bunch 
>>> of 5071A Cs clocks.
>> Interesting... what happened on day 4 to send them all bonkers?
> 
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Re: [time-nuts] Rpair of an 8662 HP Generator

[Scott McGrath]

Silicon investigations repairs them. Google the name for website

Content by Scott
Typos by Siri

On Apr 15, 2016, at 6:38 PM, John Miles  wrote:

>> My  signal generator has a poor, intermittent power  supply.  The RF
>> section is ok. Who can please tell me which company can and  will fix these
>> older
>> but excellent  generators?
>> 
>> Thanks, Ulrich
> 
> Have a look at the capacitors in the voltage divider that drives the bases of 
> the switching transistors.  There's a good chance that's your problem, and 
> they probably need to be replaced even if not.  75-TVA1607 (Mouser p/n for 
> Sprague TVA1607) works well.  
> 
> It would be nice to use 105C parts if you can find some, but the 85C TVA1607s 
> have worked well for me in multiple 8662As over several years. 
> 
> The other likely suspect is one of the large screw-terminal electrolytics on 
> the motherboard.  The power supply can almost-but-not-quite start up when one 
> of those is completely open.  High ESR is very likely to cause intermittent 
> operation. 
> 
> -- john, KE5FX
> Miles Design LLC
> 
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Re: [time-nuts] Does anyone have an inoperable TS2100 they'd part with?

[Scott McGrath]

Frequently power supplies in instruments like the TS2100 are standard off the 
shelf units.  I would suggest googling the vendor and part number and of course 
checking the well known auction site

In one case avocent wanted 1800 bucks to fix a terminal server with a dead PS I 
was able to buy a brand new exact replacement from the OEM of the PS for $150 
from Amazon


> On Apr 6, 2016, at 11:23 AM, Sean Gallagher  wrote:
> 
> Plan C at my job for keeping our time service going was running two TS2100 
> machines in conjunction with one another like what Andrew Cooper did when the 
> rollover bug hit, and which we also did for awhile. Unfortunately the power 
> unit on one of my units seems to have blown. We could see that the fuse was 
> blown and tried replacing it but still nothing and none of us are electrical 
> engineers to go any deeper into it than that.
> 
> So I thought I would see if anyone on here had any 2100s that weren't working 
> at all that my company could purchase to steal the power supply out of, or 
> even just the power conversion unit itself if you've taken your old equipment 
> apart?
> 
> Respectfully,
> 
> Sean Gallagher
> Malware Analyst
> 571-340-3475
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Re: [time-nuts] HP Reliability

[Scott McGrath]

When in the field and one of those cheap 'disposable' instruments fail and 
pointed questions are asked   That's when you miss the quality of the old HP 
gear   And I still use the old pre Carly gear precisely because it can be 
trusted to work in adverse conditions even though one needs to wash the data 
through a computer to get the measurement features that the new stuff has built 
in

The new gear had a name at one time we called it experimenter grade.  Much of 
the new gear these days reminds me of Eico equipment in overall build quality 

Content by Scott
Typos by Siri

> On Feb 14, 2016, at 2:20 PM, William H. Fite <omni...@gmail.com> wrote:
> 
> They don't wonder; they know very well. But they're stuck. Consider
> oscilloscopes. Why pay for a Keysight or Tectronix or LeCroy or, God
> forbid, a Rohde & Schwarz when, for the vast majority of applications, a
> Rigol will give you everything you need at 1/N the cost?
> 
> The hugely expensive, overbuilt gear that we grew up with is yesterday's
> news; that's why we can scarf it up so cheap on the 'bay. Lots of labs and
> manufacturing facilities now consider basic gear like DSOs, SAs, DMMs,
> PSUs, and sig-gens as disposable as cell phones.
> 
> I'm not sure that is a bad thing.
> 
> Bill
> 
> 
> 
> On Sunday, February 14, 2016, Scott McGrath <scmcgr...@gmail.com
> <javascript:_e(%7B%7D,'cvml','scmcgr...@gmail.com');>> wrote:
> 
>> HP's greatest advantage of old was being the largest and best vertically
>> integrated technology company as innovations in one line of business were
>> often applicable to others.This was right down to things as prosaic as
>> packaging and or hybrid  circuit design
>> 
>> Now Keysight is just another mid sized technology company who outsources
>> much of their production and wonders why Asian vendors can copy their stuff
>> so rapidly and undersell them.
>> 
>> Content by Scott
>> Typos by Siri
>> 
>>> On Feb 14, 2016, at 8:31 AM, Adrian Godwin <artgod...@gmail.com> wrote:
>>> 
>>> HP built their reputation for quality and reliability with test
>> equipment.
>>> Computers were always considered a bit weird (in a nice way, in the case
>> of
>>> handheld calculators) but printers have followed the consumer race to the
>>> bottom.
>>> 
>>> It's sad to hear that the instrument division are no longer focused on
>>> keeping that reputation - perhaps that's why the medical division moved
>> to
>>> separate the names.
>>> 
>>> On Sun, Feb 14, 2016 at 11:28 AM, Dr. David Kirkby (Kirkby Microwave
>> Ltd) <
>>> drkir...@kirkbymicrowave.co.uk> wrote:
>>> 
>>>>  On 14 Feb 2016 09:04, "Perry Sandeen via time-nuts" <
>> time-nuts@febo.com
>>>> wrote:
>>>>> 
>>>>> Hi,
>>>>> It is rather depressing to me to hear RK and others remark about the
>>>> unreliability of HP test equipment.
>>>>> There is one area where they had outstanding equipment.
>>>> 
>>>> I have a friend with a fairly large lab. He must have 50 signal
>> generators,
>>>> 15 spectrum analyzers, plus plenty of other stuff. Mainly RF. Most is
>>>> HP/Agilent, but he has Rohde & Scwarz and Anritsu too. He finds the HP
>> the
>>>> most reliable.
>>>> 
>>>> Also Anritsu seem to charge a lot for calibration.  A recent repair to a
>>>> modern 6 GHz Anritsu signal generator resulted in the repair bill plus
>>>> £1200 GBP (around $1800) for calibration. That particular sig gen, which
>>>> was sold for mobile phone use, has an electronic attenuator that will
>> blow
>>>> up if a mobile phone is transmitted into it.
>>>> 
>>>> He used to think he preferred R signal generators to Agilent,  but the
>>>> reliability of the R has been poorer so his mind has been changed on
>>>> that.
>>>> 
>>>> I am sure every company has some products that have been very reliable
>> and
>>>> some less so, but I would dispute that HP is in general less reliable
>> than
>>>> other decent makes.
>>>> 
>>>> Support on HP is generally good, with the forums which are answered by
>>>> Keysight staff. (An annoying exception seems to be LCR meters and
>> Impedance
>>>> analyzers developed in Japan. The Japanese engineers hardly ever visit
>> the
>>>> forums so questions on LCR meters and impedance analyzers generally get
>> no
>>>

Re: [time-nuts] HP Reliability

[Scott McGrath]

HP's greatest advantage of old was being the largest and best vertically 
integrated technology company as innovations in one line of business were often 
applicable to others.This was right down to things as prosaic as packaging 
and or hybrid  circuit design

Now Keysight is just another mid sized technology company who outsources much 
of their production and wonders why Asian vendors can copy their stuff so 
rapidly and undersell them.

Content by Scott
Typos by Siri

> On Feb 14, 2016, at 8:31 AM, Adrian Godwin  wrote:
> 
> HP built their reputation for quality and reliability with test equipment.
> Computers were always considered a bit weird (in a nice way, in the case of
> handheld calculators) but printers have followed the consumer race to the
> bottom.
> 
> It's sad to hear that the instrument division are no longer focused on
> keeping that reputation - perhaps that's why the medical division moved to
> separate the names.
> 
> On Sun, Feb 14, 2016 at 11:28 AM, Dr. David Kirkby (Kirkby Microwave Ltd) <
> drkir...@kirkbymicrowave.co.uk> wrote:
> 
>>   On 14 Feb 2016 09:04, "Perry Sandeen via time-nuts" > wrote:
>>> 
>>> Hi,
>>> It is rather depressing to me to hear RK and others remark about the
>> unreliability of HP test equipment.
>>> There is one area where they had outstanding equipment.
>> 
>> I have a friend with a fairly large lab. He must have 50 signal generators,
>> 15 spectrum analyzers, plus plenty of other stuff. Mainly RF. Most is
>> HP/Agilent, but he has Rohde & Scwarz and Anritsu too. He finds the HP the
>> most reliable.
>> 
>> Also Anritsu seem to charge a lot for calibration.  A recent repair to a
>> modern 6 GHz Anritsu signal generator resulted in the repair bill plus
>> £1200 GBP (around $1800) for calibration. That particular sig gen, which
>> was sold for mobile phone use, has an electronic attenuator that will blow
>> up if a mobile phone is transmitted into it.
>> 
>> He used to think he preferred R signal generators to Agilent,  but the
>> reliability of the R has been poorer so his mind has been changed on
>> that.
>> 
>> I am sure every company has some products that have been very reliable and
>> some less so, but I would dispute that HP is in general less reliable than
>> other decent makes.
>> 
>> Support on HP is generally good, with the forums which are answered by
>> Keysight staff. (An annoying exception seems to be LCR meters and Impedance
>> analyzers developed in Japan. The Japanese engineers hardly ever visit the
>> forums so questions on LCR meters and impedance analyzers generally get no
>> response.)
>> 
>> There are instrument ranges where other manufacturers seem better (e.g.
>> Keithley for electrometers), but overall HP/Agilent seem the best choice to
>> me.
>> 
>> I know someone who is looking for a 20.GHz VNA. He just lost out on a
>> Windows based R VNA that sold on eBay for a bit over $7000. There's no
>> way a 20 GHz Windows based Agilent VNA would fetch so little.  This is
>> reflected in their higher resale values.
>> 
>> At least with the older stuff,, service manuals for HP are useful,  though
>> modern service manuals are less so.
>> 
>> Just my opinion.
>> 
>> Dave.
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Re: [time-nuts] Calibration procedures - what is normal?

[Scott McGrath]

'Normal' calibration is a performance check and adjustments as required 

Performance checks are applying stimulus and checking instrument response is 
within the acceptable range.

A Full calibration is adjust each parameter to as close as practicable to ideal 
value and may include new cal constants and is generally far more expensive 
than a normal calibration 

Content by Scott
Typos by Siri

> On Feb 12, 2016, at 3:14 PM, Joseph Gray  wrote:
> 
> I sent my HP 3457A in for cal. I should be getting it back next week.
> I won't mention where I sent it, but it wasn't Keysight (I don't like
> that name). I recently changed the SRAM battery and purposely did not
> save the cal constants. I bought the meter second hand and it wasn't
> in spec when I bought it. I didn't care what the past data was.
> 
> The service manual lists an entire sequence of procedures for
> calibrating this DMM, starting with storing values for zero and full
> scale into the SRAM. All of this is done via the front panel, by
> pushing buttons.
> 
> I just found out that this part of the procedure is not normally done
> (at least by the lab I sent the DMM to). With no pre-existing cal
> constants, the tech I spoke to was rather annoyed that he was having
> to spend the time doing the hookups and pushing buttons for each
> function and range to store the zero and full scale values. I was told
> this added an extra hour to the normal procedure.
> 
> Not knowing what is normally done in the cal lab, I assumed that the
> entire procedure as listed in the service manual would be done. It
> seems that I was wrong.
> 
> In the end, the lab decided not to charge me for the extra time
> involved. I thanked them for that.
> 
> My question is, do any cal labs (including Keysight) normally perform
> the zero and full scale procedures as listed in the service manual?
> 
> Joe Gray
> W5JG
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Re: [time-nuts] Fwd: CGSIC: FW: Official Press Release - GPS Ground System Anomaly

[Scott McGrath]

What was interesting was in addition to the bump was that the Garmin nav 
receiver in the car was unable to get a fix until it did a full cold start

Content by Scott
Typos by Siri

> On Jan 28, 2016, at 5:37 PM, Magnus Danielson  
> wrote:
> 
> Poul-Henning,
> 
>> On 01/28/2016 11:27 PM, Poul-Henning Kamp wrote:
>> 
>> In message <56aa6aa2.6050...@rubidium.dyndns.org>, Magnus Danielson writes:
>> 
 And, did this "ripple in the force" cause all those NTP synchronized
 clocks to hiccup (if a NTP ticker is UTC driven vs GPS driven)
>>> 
>>> NTP bumping around 13,7 us... I'm not sure I *really* care for most usage.
>> 
>> I don't think most NTPD based servers would even notice the pattern I
>> saw on my receivers.
> 
> Indeed. Even if they saw it, as soon as you got past the first router that 
> bump is nothing anyways.
> 
> I just *might* have been using a bit of an understatement.
> 
> Cheers,
> Magnus
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Re: [time-nuts] New Member + Basic Questions

[Scott McGrath]

The 8660 is really a sweep generator designed for alignment of IF stages of 
airband and satellite gear.  Hence its odd frequency selections and it's 
miserable phase noise performance that being said I have a couple of them and 
the are good generators for  general purpose use if you respect their 
limitations



Content by Scott
Typos by Siri

> On Jan 15, 2016, at 12:58 AM, Rob Sherwood.  wrote:
> 
> The 8660 is a rather messy generator with five loops.  Its phase noise spec 
> within a 30 kHz bandwidth is nominally 4 dB worse than an HP 3336C. Of course 
> the frequency range of the 8660 is vastly greater than the 3336C, depending 
> on the plugin. There were 4 versions of the 8660, A, B, C & D. I mention the 
> 3336C because while a very handy synthesizer, its phase noise is terrible 
> compared to the 8640A/B. It depends on what you want to do with your 
> generator. As you said, if it can be purchased and shipped for $100, why not. 
> Alignment of the 8660 is a pain, so expect a project. Hopefully it gets 
> packed properly. Shipping damage of large and heavy test equipment is a 
> really big problem.
> 
> Rob, NC0B
> 
> Sent from my iPad
> 
>> On Jan 14, 2016, at 4:02 PM, "Nathan Johnson"  wrote:
>> 
>> 
>> 
>> What does the group think of the HP 8660? Just scored a broken one too cheap 
>> to
>> pass up. I know it's not gonna be the last signal generator I buy, but for 
>> under
>> $100 shipped it should be an interesting project.
>> Nathan KK4REY
>> 
>> Sent using CloudMagic Email
>> [https://cloudmagic.com/k/d/mailapp?ct=pi=7.4.15=9.1=email_footer_2]
>> On Tue, Jan 12, 2016 at 02:50, Discussion of precise time and frequency
>> measurement  wrote:
>> Robs correct on that front. Did not have time to respond till now.
>> The 8640 is not some sort of synthesized gen.
>> But it has one of the lowest noise floors of any generator.
>> So I have several of them and then the synthesized gens like those
>> mentioned.
>> 
>> Hear that sucking sound?
>> Its quicksand.
>> 
>> Regards
>> Paul
>> WB8TSL
>> 
>>> On Mon, Jan 11, 2016 at 3:54 PM, Rob Sherwood.  wrote:
>>> 
>>> It is more of a counter-assisted drift stabilizer than a true phase lock
>>> as would happen if locking a 10811 to an external standard. Rob, NC0B
>>> 
>>> Sent from my iPad
>>> 
 On Jan 11, 2016, at 1:00 PM, "bownes"  wrote:
 
 
 
 
 The 8640 will lock to an external 5Mhz reference. That's what the BNC in
>>> the heatsink is for. At least that is where it is on mine.
 
 The trick is doing a good divide by two.
 
 However, that said, the 8640 tops out at ~1024MHz, which if you get
>>> interested in even the lower microwaves, is not quite enough.
 
 
 
 Bob
 KI2L
 
> On Jan 11, 2016, at 09:47, Rob Sherwood.  wrote:
> 
> The HP 8647A may be the worst signal generator HP ever made. The 8656B
>>> won't even go down low enough in level to make a noise floor measurement on
>>> a modern transceiver. Sure you can add external attenuation, but you won't
>>> know about how much leakage is occurring. Otherwise why wouldn't HP have
>>> added another 15 dB attenuation in the box? That is why I mentioned the
>>> 8657B. Yes the 8662A's reliability issue is the power supply. No question
>>> not a starter generator. The 8642A was never intended for field repair,
>>> but it is the only generator with low enough phase noise to test top radios
>>> today, and something a ham could afford. Again, not the first sig gen that
>>> should be on your list
> 
> Rob, NC0B
> Sent from my iPad
> 
>> On Jan 11, 2016, at 8:01 AM, "Nathan Johnson" 
>>> wrote:
>> 
>> 
>> 
>> I really appreciate all the help. I really like that Ref0 combination,
>>> I don't
>> see any Ref1s available right now, but you are saying that any decent
>> GPS+Arduino can substitute? Should I be looking in the archives for
>>> that, or is
>> there a website?
>> Minor clarification to my earlier post about the signal gen, I am
>>> aware that the
>> 8640 won't lock to an external reference. I had intended that to read
>> 8640-something or 50-something. I'm watching an 8647 and an 8656b on
>>> the usual
>> site at the moment. That 8662 looks beautiful, but it's a huge
>>> investment for a
>> piece of old gear that has a reputation for being a bit... Cranky and
>> opinionated. I have no practical need for that now, so I won't sign up
>>> for that
>> kind of challenge until I do.
>> I'm quite familiar with how this stuff multiplies, I have a Tektronix
>>> scope
>> collection, and have been a lurker on the TekScopes list for about a
>>> year. There
>> is a running joke on that list about "scope acquisition disorder". I'm
>>> pretty
>> sure that I'm infected, but I only have 5 scopes in the house at the
>>> moment, so
>> 

Re: [time-nuts] PM6680 or 53131A for TimePod

[Scott McGrath]

5371a is a TI analyzer   The time pod itself is used for paying work so it's 
not available for time nuttery.   

Content by Scott
Typos by Siri

> On Nov 16, 2015, at 6:20 AM, Chris Caudle <ch...@chriscaudle.org> wrote:
> 
>> On Mon, November 16, 2015 12:42 am, Scott McGrath wrote:
>> More of a slip as I've noted I have a time pod for work but I'd like to
>> add a small counter for time nuttery as power is not cheap in NE so
>> running the 5371A for long runs can get expensive
> 
> I don't follow.  Why would you not use the TimePod with a lower power
> reference?  It isn't like a TimePod only works with a cesium clock as the
> reference source.
> 
> -- 
> Chris Caudle
> 
> 
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[time-nuts] PM6680 or 53131A for TimePod

[Scott McGrath]

Hi

Which counter would be best for use with time pod I have a chance to buy each 
at a reasonable prices i.e. < 1000 US

Thanks in advance Scott

Content by Scott
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Re: [time-nuts] PM6680 or 53131A for TimePod

[Scott McGrath]

Thanks Bob

I'm using the actual time pod for paying activities.  This would be a counter 
for time nuttery using the time pod software.  In those cases Where I don't 
want to fire up the 5071.  

I'm familiar with the Keysight counters and I have a lot of them into the high 
Ghz ranges

The 53131 is spec'd to 500ps and the  6680 is spec'd at 250ps 

I've also been leaning in the 53131 direction but I'd like to have the best 
tool for the job at hand

Content by Scott
Typos by Siri

> On Nov 15, 2015, at 1:59 PM, Bob Camp <kb...@n1k.org> wrote:
> 
> Hi
> 
> I guess the first question would be - If you have a Time Pod, what do you 
> need a counter for?
> 
> Based on a guess that you need extended frequency range, either would do 
> pretty well. My vote
> would go to the HP for a couple of reasons:
> 
> 1) It’s more broadly supported in terms of driver software (which may or may 
> not matter to you).
> 
> 2) It’s a more common item on the auction sites, so parts are easier to find.
> 
> 3) It shares some parts (like the power supply) with the (cheaper) 53181
> 
> No those are not great big reasons to go for one over the other. They are 
> very similar devices. One
> has an LCD that has a finite life. The other has a VFD that also has a finite 
> life. Both are custom, that’s 
> a tie. Some like the command (button) arrangement on one over the other. I 
> think it’s more a “what
> are you used to” thing than anything else. On the 53131 you need to hit the 
> Run button in some cases. 
> 
> I have not watched the prices on the Fluke. I have kept track of the 53131’s. 
> A “good price” on one
> these days is below $600 ( = you may need to shop a bit, but they do show 
> up). 
> 
> Bob
> 
>> On Nov 15, 2015, at 1:45 PM, Scott McGrath <scmcgr...@gmail.com> wrote:
>> 
>> Hi
>> 
>> Which counter would be best for use with time pod I have a chance to buy 
>> each at a reasonable prices i.e. < 1000 US
>> 
>> Thanks in advance Scott
>> 
>> Content by Scott
>> Typos by Siri
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Re: [time-nuts] PM6680 or 53131A for TimePod

[Scott McGrath]

More of a slip as I've noted I have a time pod for work but I'd like to add a 
small counter for time nuttery as power is not cheap in NE so running the 5371A 
for long runs can get expensive 

Content by Scott
Typos by Siri

> On Nov 15, 2015, at 4:08 PM, Chris Caudle  wrote:
> 
>> On Sun, November 15, 2015 3:59 pm, Bob Camp wrote:
>> I guess the first question would be - If you have a Time Pod, what do you
>> need a counter for?
> 
> Or was the original question a slip, and was supposed to be which counter
> is good for use with TimeLab software?
> 
> -- 
> Chris Caudle
> 
> 
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Re: [time-nuts] Celestial Navigation instruction being reinstated in the US Navy

[Scott McGrath]

Or with the appropriate filters you can shoot the sun with a sextant like the 
old time Mariners did
I still have a sextant and still use it along with a copy of Bowditch

Content by Scott
Typos by Siri

> On Oct 26, 2015, at 9:13 AM, Jim Lux  wrote:
> 
>> On 10/25/15 9:37 AM, jim s wrote:
>> 
>> Somewhat time related.  The Navy realizes that GPS might not always
>> work.  I don't imagine that aircraft in the US Air Force will be able to
>> do this very reliably, and the article doesn't mention that service. I'm
>> guessing that a lot of strategic Air Force aircraft have star trackers
>> that will work some of the time w/o GPS (at night).
> 
> There's an excellent set of CD-ROMs with about 50 papers on celestial nav and 
> time keeping from the Institute of Navigation.
> 
> https://www.ion.org/publications/upload/CelestialNavTOC.pdf
> 
> Papers in there about all manner of star trackers and celestial nav, from 
> prehistory through the Renaissance era, to modern computerized celestial nav 
> boxes, etc.
> 
> $50, as I recall.
> 
> Celestial nav during the daytime isn't all that hard, if you have a suitable 
> telescope.  With a 28x telescope on a theodolite, you can see Polaris, for 
> instance.  The trick is in finding it first.
> 
> 
> 
>> http://www.latimes.com/nation/la-na-celestial-navigation-20151025-story.html
>> 
>> 
>> Thanks
>> Jim
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Re: [time-nuts] "Selective availability" af accurate time for Apple users?

[Scott McGrath]

I think it has to do more with battery life as the first release of iOS 9 
drained battery faster than prior releases and the GPS is expensive from a 
power standpoint.   I think the non watch devices sacrificed precision time for 
runtime 

Content by Scott
Typos by Siri

> On Oct 20, 2015, at 12:09 PM, Paul  wrote:
> 
> On Tue, Oct 20, 2015 at 4:02 AM, Brian Garrett 
> wrote:
>> ...  As measured by NTP apps such as Emerald Time and Watchville,
> millisecond accuracy comparable to the soon-to-be-released Apple Watch was
> now commonplace, with typical offsets of 5 ms or less, rather than the
> several seconds of offset typical under the previous release.
> 
> Network connected iOS devices not paired with a watch use (s)ntp at large
> intervals rather than the mobile network or GPS.  The offsets appear to be
> somewhat random -- both positive and negative, large (s) and small (ms).  I
> assume it's related to the environment and the last time the offset was
> corrected.
> 
>> Now, with the latest version, iOS 9, the Apple Watch level accuracy
> previously available to iPhone users has gone away.  Once again, your
> iPhone will be as much as several seconds slow as measured by NTP, unless
> you force an update to the phone’s clock by opening a GPS app.
> 
> I checked on an iPad (but presumably that shouldn't matter).  My current
> offset is -1.6 s (fast, and slowly increasing) as measured by Time
> independent of GPS which I woke with Observatory which uses both NTP (for
> time) and the GPS (for location).  Restarting the iPad causes a step. This
> compares with +1 to -3 ms on my phone.
> 
> I'll admit the above is slightly speculative because I haven't checked
> network traffic yet but I will shortly.
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Re: [time-nuts] Possible GPS Interference test

[Scott McGrath]

I've been in Seattle when a AWACS has been at Boeing and GPS was non functional 
when it was on the ground this took out multiple GPS platforms the on board 
unit in the rental my portable unit plus the one in the iPhone



Content by Scott
Typos by Siri

On Sep 30, 2015, at 6:02 AM, Hal Murray  wrote:

>> Anyone else near LA notice anything?
> 
> I'm in Silicon Valley.  I got wiped out by tests from China Lake a while ago. 
> I didn't see anything this time.
> 
> Anybody know anything about the directionality of the testing?
> 
> 
>> The 1PPS received signal shifted by -2E-10 in frequency (5 minute
>> averages).
> 
> What sort of gear did that?  Was it a GPSDO that went into holdover?  Has it 
> gone into holdover at other times?
> 
> 
> 
> -- 
> These are my opinions.  I hate spam.
> 
> 
> 
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Re: [time-nuts] Why would Keysight UK uncertainty measuring 1 MHz be as high as 7.6 Hz?

[Scott McGrath]

Look at the service manual,  the calibration setup listed is usually pretty 
close to what Keysight is using in their local calibration facility.   For an 
LCR meter I doubt they would be using a time nuts grade counter

Content by Scott
Typos by Siri

 On Aug 29, 2015, at 10:02 PM, Bob Camp kb...@n1k.org wrote:
 
 Hi
 
 Well, since we all have made our totally uninformed guesses, the only 
 thing to do now is to give Keysight a call and see what the real answer 
 is. 
 
 Bob
 
 
 On Aug 29, 2015, at 1:46 PM, Dr. David Kirkby (Kirkby Microwave Ltd) 
 drkir...@kirkbymicrowave.co.uk wrote:
 
 On 29 August 2015 at 12:59, Javier Herrero jherr...@hvsistemas.es wrote:
 
 Hello,
 
 The calibration certificate does not indicate that the measurements were
 done with the frequency counters referenced to the 5071A at the time of
 calbiration (if so, it would be listed under the Calibration Equipment Used
 table). It says that the 53132A were calibrated against the 5071A.
 
 If for your calibration they have used 53132A witout the oven oscillator
 option it is very probable that its uncertainity is 7.6ppm as indicated in
 the certificate. Since the maximum error tolerable for the LCR meter is
 100ppm (+/-100Hz @ 1MHz), it makes sense to perform the measurement with an
 instrument with an uncertainity of 7.6ppm, and not to use the better
 counter in the lab for that purpose.
 
 Regards,
 
 Javier
 
 
 I would find it a bit hard to believe they would use a counter without an
 oven in their lab, as it would seriously restrict what they can do with it,
 making it more difficult to replace one counter with another. I would have
 thought that within reason it best to have the lab have reasonably high
 spec kit, so more than one instrument could be done on the same line. They
 did for example use a pair of 3458As, despite I'm sure the voltage accuracy
 requirements could be met with a multimeter with far greater uncertainty
 than an expensive 3458A. It makes more sense (within reason) to have 3458As
 in the cal lab, as it allows a wider range of instruments to be calibrated.
 
 Also, if you consider the spec on the 53132A without an oven, it is 3 x
 10^-7 per month. So after 12 months that could be 12 * 3 10^-7 or 3.6
 10^-6, so if it did drift the maximum amount each month for a year, the
 uncertainty would higher than it actually is.
 
 I intended to contact Keysight about the calibration for a couple of other
 reasons
 
 1) I would like to know if it was adjusted or not. That is not clear from
 the cal certificate, since the
 
 * As received condition  - Not applicable, as this calibration certificate
 applies to the initial calibration of a new, refurbished or upgraded
 equipment.
 * Action taken  - The equipment was upgraded.
 
 I doubt it has seen a cal lab in ages.
 
 The upgrade was just a software one, to enable cable lengths of 2 m and 4 m
 (option 006) to be used to connect the DUT, which they kindly provided free
 of charge, on the condition I paid for the calibration.
 
 2) They never put any stickers over the screws that prevent the covers
 being removed, which struck me as a bit odd.
 
 Since I was going to ask about those two issues, I will ask about the
 uncertainty on frequency too. It will be interesting what response I get.
 I'm just interested -  I realize that this instrument does not demand much
 of the counter used to calibrate it. The demanding calibration devices
 would be the resistance and capacitance standards.
 
 Dave
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Re: [time-nuts] Loran C returning to a station near you...

[Scott McGrath]

What GRI is in use I'll fire up my austron as well Central NH location

Content by Scott
Typos by Siri

 On Jul 18, 2015, at 1:42 PM, paul swed paulsw...@gmail.com wrote:
 
 Bill I will let you know what the Austrons say for signal level. Fact is
 they locked up fast.
 My FS700 is taking its time.
 
 Graham it will sound different as there are no competing stations on other
 GRIs. Thats the very first thing that hits you. Additionally its only 1
 station. But that same station is sending the master and secondary delayed
 emission. Its simply not the same ole sound. But it still works very well
 for checking frequency.
 
 Regards
 Paul
 WB8TSL
 
 On Sat, Jul 18, 2015 at 12:52 PM, billriches bill.ric...@verizon.net
 wrote:
 
 Correction on times for Mon - thurs - start 900 edst - 1300Z
 
 
 -Original Message-
 From: billriches [mailto:bill.ric...@verizon.net]
 Sent: Saturday, July 18, 2015 7:05 AM
 To: 'billriches'; 'Discussion of precise time and frequency measurement'
 Subject: RE: [time-nuts] Loran C returning to a station near you...
 
 FYI Wildwood eLoran will be fired up 1300Z Saturday (today) and 1300Z
 Monday
 thru Thursday.  Happy listening.  Any reports would be appreciated and I
 will pass them along to the engineer that is driving the train.
 
 73,
 
 Bill, WA2DVU
 Cape Mahy
 
 -Original Message-
 From: billriches [mailto:bill.ric...@verizon.net]
 Sent: Thursday, July 16, 2015 10:04 PM
 To: 'billriches'; 'Discussion of precise time and frequency measurement'
 Subject: RE: [time-nuts] Loran C returning to a station near you...
 
 
 FYI GRI for Wildwood is 8970.
 
 Bill, WA2DVU
 Cape May
 
 
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 This email has been checked for viruses by Avast antivirus software.
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Re: [time-nuts] UrsaNav LORAN next test date

[Scott McGrath]

The Dymec 100 active antenna systems are also a good choice and don't require a 
DC block between the Austron and antennas   As they are split into an indoor 
and outdoor unit

Content by Scott
Typos by Siri

 On Jul 16, 2015, at 9:09 AM, paul swed paulsw...@gmail.com wrote:
 
 Dan
 I have several 2100s and 2100Fs and they are a really good unit. Feed in
 your local reference and it will tell you the offset from the loran
 station. The loran signal typically uses 3 CS references. Certainly
 distance and propagation enter into the picture as far as accuracy goes.
 But as an alternate reference to GPS you can't complain.
 If you can find a marine loran c boat preamp and antenna you are in
 business.
 Regards
 Paul.
 WB8TSL
 
 On Thu, Jul 16, 2015 at 1:45 AM, D W watsondani...@gmail.com wrote:
 
 Paul, thanks for that info. Very interesting. I've been enjoying all of
 the Loran talk on the mailing list recently.
 
 I just picked up a NOS 2100F on eBay to play around with. Maybe I'll be
 able to do something useful with it one day if they continue with eLoran
 tests.
 
 Dan
 
 On Jul 15, 2015, at 1:17 PM, paul swed paulsw...@gmail.com wrote:
 
 I reached out to UrsaNav and asked when the next test would be.
 They were very responsive.
 
 Wildwood, NJ will be on air from 0900 (local) on 20 July until 0900
 (local)
 on 23 July for an eLoran test.
 
 So fire up your Austrons and SRS units.
 
 There will be additional tests and they may be from different sites.
 UrsaNav plans to post the schedules on their site when it firms up.
 Regards
 Paul
 WB8TSL
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Re: [time-nuts] z3801a - serial help and for sale.

[Scott McGrath]

Try going through all the speeds starting at 300.  Sounds like a baud rate 
mismatch to me from the symptoms 

Also try 8 bits 1 stop no parity 

Content by Scott
Typos by Siri

 On Jun 10, 2015, at 10:28 AM, David Andersen d...@pobox.com wrote:
 
 I'm throwing my hands up in the air - I don't have the time to wrestle my
 silly mac into trying to talk to the box, unless someone has quick advice
 on something I might be doing wrong.
 
 z3801a, jumpered to RS232, modified with an internal switching power supply
 (see photos below).  Power light comes on, unit is outputting stable
 10MHz.  Doesn't GPS lock, but that makes sense, since I haven't been able
 to issue a SURVEY command and I don't live where I used to.
 
 The internal green status light is blinking (as normal), suggesting that
 it's probably happy and I'm an idiot for not being able to make it work,
 but I don't vouch for anything about it past the 10mhz being there.  The
 double-oven oscillator is clearly happy given the 10mhz (compared against a
 working Thunderbolt).
 
 Hooked up a serial cable at 19200, 7, O, 1, but only got a garbled little
 prompt back - no response to standard z3801a commands.  I *think* I have
 the cable configured properly.  I opened it up and checked the RS232
 jumpers and they're correct.
 
 I'm open to advice on getting the serial working under my Mac or Linux, or
 anyone who wants to relieve me of the burden of z3801a ownership and take a
 risk that it's a fixer-upper. :-)  I suspect that in some previous life, I
 switched it over into a binary mode of some sort while using it to sync
 something, but I can't for the life of me remember what I might have done.
 
 Some reasonable price plus shipping and it's all yours... I'm trying to
 de-clutter in preparation for a sabbatical on the other side of the country.
 
 Pictures:
 
 https://www.dropbox.com/s/ursszjgie8m1xj8/2015-06-09%2011.57.16.jpg?dl=0
 https://www.dropbox.com/s/it8d2f65ztn4rkq/2015-06-09%2011.57.24.jpg?dl=0
 https://www.dropbox.com/s/1p1g6xrapzdmvzh/2015-06-09%2011.59.56.jpg?dl=0
 
 Thanks!
 
  -Dave
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Re: [time-nuts] iGPS?

[Scott McGrath]

Not necessarily,  you are assuming a single large jammer you could easily 
disperse a large number of small narrowband jammers over an area you wanted to 
deny GPS coverage to via airdrops or artillery and that would effectively deny 
coverage and make it almost impossible to suppress all the jammers.

Content by Scott
Typos by Siri

 On May 18, 2015, at 3:56 PM, Chris Albertson albertson.ch...@gmail.com 
 wrote:
 
 Any wide area and broadband military jammer is taking a big risk
 because the jammer is very easy to find.
 
 If Apple is buying into this then it is not military and they are
 looking to put it inside a phone or maybe a car.
 
 On Mon, May 18, 2015 at 11:06 AM, Brooke Clarke bro...@pacific.net wrote:
 Hi Bob:
 
 In the link in the message from Brian it explains that iGPS is for military
 users of the Iridium system.
 The key feature is to allow a moving vehicle to lock on the GPS signal while
 being jammed.  They do that and also get a more accurate fix by using
 signals from the Iridium satellites.
 
 I see a potential problem in that the Iridium signals are close in frequency
 to GPS and a broad band jammer might cause a problem for both of them.
 Mail_Attachment --
 Have Fun,
 
 Brooke Clarke
 http://www.PRC68.com
 http://www.end2partygovernment.com/2012Issues.html
 http://www.prc68.com/I/DietNutrition.html
 Bob Camp wrote:
 
 Hi
 
 “Orders of magnitude” more accurate …
 
 Right now, you can get around ~1 M in most areas. One order of magnitude
 would be 10 cm.
 More than one order of magnitude would be 10 mm. To me “orders” implies
 more than two, so that
 would be 1 mm.
 
 I guess everybody can toss out all their multi band GPS gear, there’s no
 need for it anymore.  No need
 to put up all those expensive block III GPS sat’s either :)
 
 hm……I do believe the marketing boys have been playing with the
 numbers. You would have to start
 from a 50 M error to get them to make much sense based on what they are
 doing.
 
 ===
 
 If you dig a bit more, Apple bought Coherent Navigation almost a half year
 ago. The main purpose appears
 to be merging their mapping software into Apple’s ill-fated maps program.
 Given that Iridium is a “pay’
 service (as in $) you probably will not see it in run of the mill cell
 phones very soon ….
 
 Bob
 
 On May 17, 2015, at 7:07 PM, Chris Albertson albertson.ch...@gmail.com
 wrote:
 
 Anyone know anything about iGPS?  Apparently the Iridium low orbit
 communications sats are now modified via software update to send
 signals that when combined with GPS allow for a receiver that is MUCH
 more precise and harder to jam and can work in urban areas better.
 Apple just bought a company that is building iGPS receivers.   Looks
 like something that they might want to put inside a cell phone but
 when you have an orders of magnitude important in position you'd
 expect better timing too, or so I would think.
 
 Seems like a very smart idea if all that was required was a software
 upload to existing spacecraft.  From what I read this is real, not a
 proposal another are real receivers being tested.
 
 
 --
 
 Chris Albertson
 Redondo Beach, California
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 -- 
 
 Chris Albertson
 Redondo Beach, California
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Re: [time-nuts] time-nuts Digest, Vol 127, Issue 33

[Scott McGrath]

The downconverter was used for long runs of cable typical use case was a high 
rise with data center in basement As I recall it converted the signal to a 
high level baseband and amplified that whic was good for a thousand feet or so 
of cable

Content by Scott
Typos by Siri

 On Feb 27, 2015, at 5:14 AM, Al Wolfe alw.k...@gmail.com wrote:
 
   I have an XL-DC and it has an internal GPS receiver in it. It supplies and 
 monitors 5 volts to a BNC antenna  jack for an external amplified GPS 
 antenna. I don't know what the internal GPS engine is but doubt if it is 
 anything special.
 
   The manual describes the down converter system as an option.
 
 Al, k9si
 
 
 Boy I ran out to mr google and did a search and now I am wondering if some
 versions of the xl-dc just used a plain old GPS antenna. It sure looks like
 that could be the case. The manual does say down converter. Maybe it
 changed over time.
 Regards
 Paul
 WB8TSL
 
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Re: [time-nuts] What are some cw signal Generators for ATE test?

[Scott McGrath]

The Agilent 8340 series might be useful here - little weak in the phase noise 
area but they offer frequency and power sweeps. And you did say economy was a 
key requirement

Content by Scott
Typos by Siri

 On Jan 17, 2015, at 9:59 PM, Ivan.Cousins ijcous...@frontier.com wrote:
 
 time-nuts members:
 
 What are some signal generators for ATE test?
 
 Requirements:
 100MHz to =10GHz (higher would be better)
 Settling time less than 1mS
 Reasonable phase noise
 Cost, less than mortgaging a house.:)
 
 Just a single tone that can be moved reasonably fast.
 IQ modulation not required.
 
 Application: Testing ICs or small RF modules.
 
 I do not want suggestions of how one could be built.
 I am aware of pieces that can be used to build one.
 Generally, the units that are based upon YIGs or YIG tuned filters are not 
 fast enough.
 I am not looking for general discussions on how one could be designed or 
 measured.
 Although, this being time-nuts, that will probably happen anyway.:)
 
 What I am looking for is one that can be purchased and be used in a test 
 system.
 I am looking to build a list of possible instruments that can be used.
 
 Right now I am only looking at what is on the market for a survey.
 I am not looking for salesmen to call or write to me.
 I have done the standard google searches and looked on the usual instrument 
 company web sites.
 
 Links to other surveys that are available are welcome.
 I may have missed some.
 
 
 Some instruments that I am aware of at the moment are:
 Keysight N5183B
 Rhode-Schwarz SGS100A
 Ni-PhaseMatrix USB 20GHz
 Apria Technology ULNsyn-MD20
 
 What are some others?
 
 Thank you.
 
 Ivan Cousins
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Re: [time-nuts] Ventilation of HP 58503A GPS time frequency reference receiver

[Scott McGrath]

From pictures bumpers are installed in an inverted position.  Reverse them

Whoever put this together in CN did not have any idea of how this series of 
cases are assembled or did not care

Content by Scott
Typos by Siri

 On Dec 13, 2014, at 2:08 PM, HP-mini blm-ubu...@slingshot.co.nz wrote:
 
 On Sat, 2014-12-13 at 15:18 +, Dr. David Kirkby (Kirkby Microwave
 Ltd) wrote:
 
 I just noticed. Since there are no feet on this, there is no way any
 air can get into the slots in the base The oven was running too
 hot for me to touch - I doubt that is normal, but perhaps others no
 different.
 
 Dave
 
 Pull the rear rubberized plastic bump stop off the case  fit it up the
 other way.
 
 As long as the OCXO operates below its turning point it has thermal
 control. Only need to dissipate the non-heating power, that sets the max
 operating temperature.
 Some OCXOs are quieter running in high temperature ambient still air.
 All are degraded by changes in thermal load.
 Brett.
 
 
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Re: [time-nuts] Ventilation of HP 58503A GPS time frequency reference receiver

[Scott McGrath]

Much of the Malaysian Agilent gear uses this style of case with a wraparound 
bumper in place of the system II feet and feet are removed when gear is rack 
mounted.

One of my best surplus buys ever was a huge crate of mixed mounting hardware 
feet / rack flanges etc I've been using that box o stuff for 10 years

Content by Scott
Typos by Siri

 On Dec 14, 2014, at 3:09 PM, Bob Camp kb...@n1k.org wrote:
 
 Hi
 
 The desktop version (with handle) used the rubber “bumper” wrap around for 
 feet. The bumpers got pulled when they were rack mounted. The ones that got 
 put back on may or may not be identical to the originals. That’s a very 
 normal part of the surplus process. The 100% correct HP original case on the 
 box as HP built it did not use the clip on feet. 
 
 The reason for this is pretty simple. The Z3801 / Z3805 came before the 
 “instrument” versions of the same products. The internal case structure is 
 same/ same. The instrument simply gets a gray sheet metal jacket that fits 
 around the Z38xx box. That’s the way HP designed it. Since its just a jacket, 
 it gets feet as part of the bumpers. Most of these (likely 99%) got rack 
 mounted and the feet / bumpers were tossed. I have a *lot* of very legit 
 surplus HP gear that did not come with feet or bumpers. 
 
 Bob
 
 On Dec 14, 2014, at 2:46 PM, Dr. David Kirkby (Kirkby Microwave Ltd) 
 drkir...@kirkbymicrowave.co.uk wrote:
 
 On 14 December 2014 at 19:32, Bob Camp kb...@n1k.org wrote:
 
 There are not the usual 3 holes underneath where feet go.
 
 I understand that they are different. The problem is the same though. 
 Pulling a box in and out of a rack with feet or bumpers on it is a pain. 
 They often get “lost” early in the instrument’s life. Often it’s a standard 
 process on all gear as it comes into the facility.  All of the un-needed 
 bits and pieces go into a big pile. When the feet (or whatever) are found 
 later in life they may or may not be re-installed correctly. They might not 
 even be the ones that came with the instrument.
 
 Bob
 
 I am not sure if you are following me. On most (all??) HP kit I have
 seen, there are 3 holes at each corner of the bottom, where is
 possible to fit feet if one is going to use it on a desktop, rather
 than a rack. This unit does not have those holes, so it would be
 impossible to fit the usual HP feet on it.
 
 Looking around, I have 15 bits of HP kit,  all of which have holes in
 the corner for feet. But this 58503A, with the Chinese box, does not
 have the holes. I don't know whether the 85053A is supposed to have
 them, or whether this is just a flaw in the design of the counterfeit.
 
 Dave
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Re: [time-nuts] 1900kHz radiolcation testing on east coast US?

[Scott McGrath]

Also hearing in central NH sounds like a new 'Woodpecker'   Joy... 

Content by Scott
Typos by Siri

 On Dec 8, 2014, at 2:24 AM, Chris Wilson ch...@chriswilson.tv wrote:
 
 Hello,
 
 on 08/12/2014 07:21  you wrote:
 
 
 I'm hearing the same signal in northern New Hampshire.
 Very strong
 
 73, Frits W1FVB
 
 
 
 
 This is audible here in the UK and elicited many comments on 160
 meters last night. Seen as oblique striations on SDR receiver displays
 and audible as a clicking sound. What the devil is it?
 
 
 
 
 
 
 -- 
   Best Regards,
   Chris Wilson.
 
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Re: [time-nuts] Did a member of time-nuts buy this?

[Scott McGrath]

If you could get the rebuild cost to 3-5K there probably would be a market.

 But that would be more of a vacuum nuts project as high vacuum systems are a 
black art. 

You would need to open the physics package with a lathe   Remove the Cs residue 
replace the ionizer and poss the mass spec.  Put a new Cs ampule in place.  
Reweld the housing and evacuate it to ion pump levels.

Not an easy task.   Doable but not easy and since the primary customer for Cs 
is the price no object crew who just buys new.   Not much of a driver to 
develop a process

Content by Scott
Typos by Siri

 On Dec 6, 2014, at 1:47 PM, Dr. David Kirkby (Kirkby Microwave Ltd) 
 drkir...@kirkbymicrowave.co.uk wrote:
 
 On 6 Dec 2014 18:33, Bert Kehren via time-nuts time-nuts@febo.com wrote:
 be done, the real issue who would buy one people that need
 Cesium  will pay the price for a new one and time nuts would not spend the
 money for a  working rebuild tube. Where is the market?
 
 There's a professional market for thermionic tubes above 10 kW or so.
 Commercial companies will buy rebuilt tubes. Why should it be any different
 with a Cs tube?
 
 I just searched some of my old emails on time-nuts, and can see it is felt
 to be impractical to rebuild a tube.
 
 Dave.
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Re: [time-nuts] [hp_agilent_equipment] Re: Upgrade an HP 5342A microwave frequency counter to have an oven oscillator.

[Scott McGrath]

The 5342A counter and the 5345A counters both predate the 10811A and were 
originally fitted with 10544A oscillators for the option 1 high stability 
timebase 

Once the 10811A was released the instruments were fitted with the 10811A as a 
production change going forward and service replacements were done using 
10811A's

So in this case there is no need to overthink the oscillator choice for 
upgrading a 5342A counter.   

 If the 10811A is an edge connector version it will fit and provide better 
performance than standard TCXO

Content by Scott
Typos by Siri

 On Dec 2, 2014, at 4:53 AM, Dr. David Kirkby (Kirkby Microwave Ltd) 
 drkir...@kirkbymicrowave.co.uk wrote:
 
 On 2 Dec 2014 03:10, wb6dgn_...@att.net[hp_agilent_equipment] 
 hp_agilent_equipm...@yahoogroups.com wrote:
 
 Isn't the 10811 a double oven oscillator (an oven within an oven)?  I
 also believe it has anticipator circuitry to predict changes based on
 environmental parameters.  Or...am I confusing this with another oscillator?
 
 http://www.leapsecond.com/museum/10811a/10811a.pdf
 
 Has a data sheet.  I believe that there are variants of the 10811A that are
 double oven, but not all are.
 
 The fan is not blowing directly onto the oscillator,  as they are on
 opposite sides of the case. But they are both at the rear and given the
 instrument is only half the width of a 19 rack, maybe it is too close.
 
 I have not checked this myself,  but someone said that the 5342A pre-dates
 the 10811A, so if purchased a 5342A new with the high stability
 oscillator,  one would get another oscillator with a poorer specification.
 
 The  5342A/10811A combination is one of those things one would have to
 test, rather than guess. It would need some careful thought about how to do
 a worthwhile experiment.
 
 Anyway, as far as I am concerned,  it is certainly worth while fitting the
 10811A, as even without any equipment other than my eyes, I can see the
 last few digits are not constantly changing every second or so.  There's a
 dramatic improvement in short term stability.  I would guess it has  2-3
 orders of magnitude better short term stability, based just at looking at
 the display.  Actual measurements would quantify the improvement.
 
 If I can get 100-1000x better performance,  for an upgrade that costs less
 than 25% of the instrument, that is worthwhile to me. Waiting 6 or so
 minutes to get a dramatic improvement in performance is not a big deal.
 Keeping it plugged in 24/7, for a bit more performance, is not worthwhile
 to me, but others may feel otherwise.
 
 Dave.
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Re: [time-nuts] Upgrade an HP 5342A microwave frequency counter to have an oven oscillator.

[Scott McGrath]

Just remove the TCXO the 10811 just plugs in,  you will need to add the heater 
oven indicator wiring and LED indicator which is usually over the power switch  
 The power supply includes the oven supply already 

Content by Scott
Typos by Siri

 On Nov 27, 2014, at 5:38 PM, Dr. David Kirkby (Kirkby Microwave Ltd) 
 drkir...@kirkbymicrowave.co.uk wrote:
 
 The HP 5342A has an optional oven oscillator. I just bought one of
 those counters, but mine has a TCXO and is about 50 kHz off at 10 GHz.
 I'm sure I can trim it closer than that, but if possible I'd like to
 stick an oven oscillator in it. Does anyone know what is involved? I
 have at least one 10811A oscillator here that I could stick inside,
 but does it need any more, or just the oscillator?
 
 Someone said the oscillator should be an 10544-60011, but a 10811A is
 backwards compatible.
 
 Dave
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Re: [time-nuts] Upgrade an HP 5342A microwave frequency counter to have an oven oscillator.

[Scott McGrath]

You are correct  I was referring to the 'instrument' version of the 10811A with 
the edge connector.   

There are a lot of 10811A variants out there but the edge connector version was 
used in most HP instruments with an ovenized time base of that vintage.

It's worth buying dead option 1 instruments as they will have either a 10544 or 
10811A as the time base mount point and electronic interface are standardized 
so upgrades are easy.


Content by Scott
Typos by Siri

 On Nov 27, 2014, at 7:01 PM, Bob Camp kb...@n1k.org wrote:
 
 Hi
 
 In this case I suspect he’s referring to the version with the edge connector 
 on it. That’s the one most instruments use rather than the connector only 
 version or the “double oven” version. I believe that makes it a 10811A rather 
 than a 10811B. 
 
 There are a multitude of details here:
 
 https://www.febo.com/pages/hp10811/HP10811AB-Manual.pdf
 
 There are indeed other versions that came out after the manual. 
 
 Bob
 
 On Nov 27, 2014, at 5:48 PM, Didier Juges shali...@gmail.com wrote:
 
 Just remove the TCXO the 10811 just plugs in
 
 Note that there are many different versions of the 10811. I am familiar
 with at least two incompatible mechanical configurations: one is
 connectorized and the other is not.
 
 Didier KO4BB
 
 On Thu, Nov 27, 2014 at 5:43 PM, Scott McGrath scmcgr...@gmail.com wrote:
 
 Just remove the TCXO the 10811 just plugs in,  you will need to add the
 heater oven indicator wiring and LED indicator which is usually over the
 power switch   The power supply includes the oven supply already
 
 Content by Scott
 Typos by Siri
 
 On Nov 27, 2014, at 5:38 PM, Dr. David Kirkby (Kirkby Microwave Ltd) 
 drkir...@kirkbymicrowave.co.uk wrote:
 
 The HP 5342A has an optional oven oscillator. I just bought one of
 those counters, but mine has a TCXO and is about 50 kHz off at 10 GHz.
 I'm sure I can trim it closer than that, but if possible I'd like to
 stick an oven oscillator in it. Does anyone know what is involved? I
 have at least one 10811A oscillator here that I could stick inside,
 but does it need any more, or just the oscillator?
 
 Someone said the oscillator should be an 10544-60011, but a 10811A is
 backwards compatible.
 
 Dave
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Re: [time-nuts] HP 5342A (18 GHz) vs 5352B (40 GHz) frequency counters

[Scott McGrath]

I've got a few of the 5342s their weak point is the sampler.  It can be fixed 
if you have a die bonder all of mine have the option 1 which is either a 10544 
or 10811 depending on vintage

The 535x series are nice counters I've got a couple. The bad thing is parts are 
even less  available because all the magic happened on a hybrid circuit which 
is NLA from keysight and was around $1800 when it was.

As to the comment on GPIB it's very popular still as it's a universal interface 
with a defined interface which is vendor independent and every piece of gear 
we've bought recently has included it as a standard option.

Yes instruments are coming with Ethernet but that's mainly for remote front 
panel operation.   It's useful when you can send a field tech with an 
instrument who's a local in country have them connect and then you can drive 
from the comfort of your office and transfer results for analysis

But for data collection and production LabView and GPIB still rule the roost.

Sent from my iPhone

 On Nov 21, 2014, at 5:29 PM, paul swed paulsw...@gmail.com wrote:
 
 David a free opinion and thats about what its worth.
 The 5342 counter was a good counter but very old now.
 I used to use the 5342s for satellite work and always wanted one for home.
 But given its age circa 1980 I believe, maybe it works or not at all
 frequencies.
 I would simply go with the 5352b because at least there is some chance to
 find parts if needed.
 As I say not a great answer.
 Regards
 Paul
 WB8TSL
 
 
 On Fri, Nov 21, 2014 at 4:51 PM, Dr. David Kirkby (Kirkby Microwave Ltd) 
 drkir...@kirkbymicrowave.co.uk wrote:
 
 I am looking for a microwave frequency counter and won an auction for an 18
 GHz 5342A with the GPIB option today @ £200 (GBP). I have just paid for
 that.
 
 I also have the chance to get a 5352B 40 GHz counter for £500. That has
 GPIB as standard.
 
 In the short/medium term I don't see much use for a 40 GHz counter, but I
 am giving consideration to buying the 40 GHz and selling the 18 GHz one.
 
 I would be interested to know if anyone has any opinions on the relative
 merrits of the two counters.
 
 Neither of these counters have ovens,  but stability is not a major issue
 given they take a 10 MHz input. That said, foes anyone know if these take
 fairly common 10811A ovens? There is a chance I would use it in places
 where it would not practical to feed in 10 MHz.
 
 Dave
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Re: [time-nuts] Electrolytic Capacitor Question

[Scott McGrath]

I've taken a hybrid approach I'm using an in circuit ESR meter to determine 
whether cap needs to be replaced 

Tantalum capacitors usually fail because of running them too close or at rated 
voltage.  HP unlike others in the industry did not tend to do this so I've had 
a low incidence of tantalum caps fail.  Generally the only ones I would replace 
are ones called out in service notes  or manual updates for uprating in value.

As others have said electrolytics and tantalums look quite different on a 
network analyzer and HP frequently selected parts for their performance 
characteristics

As to electrolytics the Panasonics are good but personally I've spent the extra 
money and used exact replacement Vishay Sprague electrolytics and Tantalums 
since they were the OEM for most of those parts when gear was built

Sent from my iPhone

 On Nov 8, 2014, at 6:32 PM, Perry Sandeen via time-nuts time-nuts@febo.com 
 wrote:
 
 List,
 
 OK everybody, let’s not get our pacemakers wound upG
 
 The problem. (Long Intro)
 
 I have about 15 pieces or so of older HP test equipment.
 3586B, 5370B, 5335A to name a few.  Because of their age of 20+ years a few 
 have failed and need repair. I
 have decided to go on a wholesale electrolytic capacitor replacement on all of
 them. (Mouser will be able to declare an extra dividend)
 
 For all the *standard* types I’ve chosen mostly Panasonic
 105C 10,000 hour caps. So far, so good.
 
 Now I come to the issue of the wet-slug tantalums that were
 used.  At the time of manufacture, these
 were the best and most expensive low voltage electrolytics available.
 
 The question is: can one replace the tantalums with the high
 grade (105C) Panasonic or Nichicon capacitors with an equal or higher
 capacitance value?
 
 Even using the *tear drop* new replacements one is looking
 at very heavy $$$.
 
 Regards,
 
 Perrier
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Re: [time-nuts] [Bulk] Re: New Guy, has HP 5061A with DATUM 7105A tube seeks advice

[Scott McGrath]

The datum tubes are fairly common as they were significantly less expensive 
than HP/Agilent tubes and lasted longer 

First thing as JL notes is to remove battery and charger 

Just power it up and monitor the ion pump value on the test meter if it drops 
to zero fairly rapidly the tube may still be good

Depending on length of storage this may take up to a week to settle to zero



Sent from my iPhone

 On Nov 6, 2014, at 7:54 AM, J. L. Trantham jlt...@att.net wrote:
 
 I agree.  Plug it in and see what happens although I would probably 
 disconnect and remove the NiCd batteries and inspect for and clean up any 
 leakage issues.  I would also remove A2, the battery charger board, until 
 initial tests are completed.  A2 is the center board seen from the bottom.
 
 I suspect the plug you have is correct.  You probably have to disassemble it, 
 rotate the 'insert' to the proper orientation for the socket on the back, 
 'file out' a small 'ridge' in the proper 'orientation groove'  on the 
 'insert' that will allow the 'insert' to be reinstalled in the 'housing', 
 then reassemble the plug.  Make sure the electrical pins and sockets 'line 
 up' (A to A, B to B, and G to G) between the insert and the socket on the 
 back of the unit.  I had to do that on mine.
 
 Good luck.
 
 Joe
 
 -Original Message-
 From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Azelio 
 Boriani
 Sent: Thursday, November 06, 2014 6:39 AM
 To: Discussion of precise time and frequency measurement
 Subject: [Bulk] Re: [time-nuts] New Guy, has HP 5061A with DATUM 7105A tube 
 seeks advice
 
 It is not uncommon that replacement tubes are not the original ones. See here:
 http://www.gigatest.net/datum/cesium_tubes.pdf
 You can't do anything else than plugging it in and check the various 
 voltages. If there is any life left in the tube and the ion pump is working, 
 you can even experience a locked status in hours (tens of hours, maybe).
 
 On Thu, Nov 6, 2014 at 8:21 AM, Wayne Holder wayne.hol...@gmail.com wrote:
 I recently picked up a 5061A surplus, but have no idea whether it 
 works or not.  The first hurdle is getting a power cord, but I'm still 
 waiting for the proper connector to show up (the first one I ordered 
 had the wrong orientation on the 3 pins.)  In the meantime, I've been 
 reading though what materials I can find online in order to figure out 
 how to  try and safely turn it on and see if the tube is OK, or dead.
 
 However after removing the top cover, I can see that my unit doesn't 
 seem to contain the typical kind of cesium tube assembly I see in the 
 HP docs I've found online.  Instead, it has a tube made by DATUM with 
 the following markings on the label:
 
 Model: 7105A
 Serial: 9951991226
 Part No: 03667-501
 Oven Temp: 92 degrees C
 Oven Monitor Therm: 101 Ohms
 EMV: 2000 DC
 NSN __ 5960 01214 7475
 
 Can anyone tell me about this model and why it might have a DATUM tube 
 rather than the kind I see in the HP oc?  Also, any advice on how to 
 safely check it out?
 
 I bought this thing out of curiosity but, upon looking inside at all 
 the various dials and switches and multi-turn potentiometers, I find 
 I'm rather intimated by it, even though I have a fairly decent 
 background in electronics.
 
 Wayne
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Re: [time-nuts] New Guy, has HP 5061A with DATUM 7105A tube seeks advice

[Scott McGrath]

Option 4 is the high performance beam tube which traded shorter life for better 
performance.   It referred to the original tube shipped with the standard 

Not sure about j15 

Sent from my iPhone

 On Nov 6, 2014, at 5:34 PM, Wayne Holder wayne.hol...@gmail.com wrote:
 
 Thanks for all the great suggestions.  I was able to unplug and remove the
 battery and, as suggested, also removed the center PCB (battery charger?/
 cutover switch?)
 
 The back of the unit indicates it has three options installed.  Option 3,
 option 4 and option J15.  Option 3 seems to be the combination of the
 battery option and the time standard option (PPS, etc.), but I'm not sure
 what option 4 and option J15 are.  Can anyone tell me?  Also, the first two
 option stickers (3  4) look like they were put on at the factory, as they
 match the serial number label in style (see attached photo.)  However, the
 option J15 sticker is a completely different color (blue) and put only
 slight askew, although it does say Hewlett Packard on the bottom of the
 label.
 
 AS for the suggestions about leaving the unit powered up for a few weeks,
 or more, so it can pump down; I'll give that a try.  However, before I
 power it up, do I need to check anything in particular (cables, switches,
 etc.) to make sure it's ready to be turned on?  I'd hate to break it just
 because I didn't know some needed startup voodoo.
 
 Wayne
 
 [image: Inline image 1]
 
 On Thu, Nov 6, 2014 at 10:01 AM, paul swed paulsw...@gmail.com wrote:
 
 Pete thats quite a hint on the official fumes measurement scale.
 Frankenstein takes a solid 24 or so hours to your one. So it seems on the
 CS scale of life you are fumes and I am wisps. The meter shows just about 0
 photo. Very tough to work with have to play games with meter amplifiers and
 such.
 But I do get the green and the darn thing does lock on its own with
 reasonable 2nd harmonic.
 So there you go Wayne. Always hope.
 Regards
 Paul
 WB8TSL
 
 On Thu, Nov 6, 2014 at 12:54 PM, Pete Lancashire p...@petelancashire.com
 wrote:
 
 If after say a week and the current does not go down, there is one more
 thing you can do before you have a tube that qualifies as a door stop.
 You
 replace the internal HV supply with 3,500V @ 5 mA I had to do this on
 mine.
 Keep doing it a few minutes at a time, took something like 3 hours.
 No drop in current until the very end and all of a sudden the current
 starting going down. I put the tube back in the 5061A and after the
 current
 dropped there was enough Cs left to get the thing to work. Just like Paul
 I'm sure there is very little left.
 
 I turn it on every 3-4 months and let it run for about an hour. The last
 few times it took a while to lock and go 'green'
 
 -pete
 
 
 
 On Wed, Nov 5, 2014 at 11:21 PM, Wayne Holder wayne.hol...@gmail.com
 wrote:
 
 I recently picked up a 5061A surplus, but have no idea whether it works
 or
 not.  The first hurdle is getting a power cord, but I'm still waiting
 for
 the proper connector to show up (the first one I ordered had the wrong
 orientation on the 3 pins.)  In the meantime, I've been reading though
 what
 materials I can find online in order to figure out how to  try and
 safely
 turn it on and see if the tube is OK, or dead.
 
 However after removing the top cover, I can see that my unit doesn't
 seem
 to contain the typical kind of cesium tube assembly I see in the HP
 docs
 I've found online.  Instead, it has a tube made by DATUM with the
 following
 markings on the label:
 
 Model: 7105A
 Serial: 9951991226
 Part No: 03667-501
 Oven Temp: 92 degrees C
 Oven Monitor Therm: 101 Ohms
 EMV: 2000 DC
 NSN __ 5960 01214 7475
 
 Can anyone tell me about this model and why it might have a DATUM tube
 rather than the kind I see in the HP oc?  Also, any advice on how to
 safely
 check it out?
 
 I bought this thing out of curiosity but, upon looking inside at all
 the
 various dials and switches and multi-turn potentiometers, I find I'm
 rather
 intimated by it, even though I have a fairly decent background in
 electronics.
 
 Wayne
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Re: [time-nuts] [Bulk] There seems to be something missing from this eBay item.

[Scott McGrath]

The only problem with these standards is the tube availability since they have 
that neat little rom which allows the standard to recognize the tube.  

 So using available non-5071 tubes  is a challenge unless someone solved the 
rom issue

But the first one is pretty beat did someone have a bad day in the standards 
lab???

Sent from my iPhone

 On Nov 6, 2014, at 7:24 PM, J. L. Trantham jlt...@att.net wrote:
 
 3$?
 
 Or is that too much?
 
 Joe
 
 -Original Message-
 From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of xaos
 Sent: Thursday, November 06, 2014 12:10 PM
 To: Discussion of precise time and frequency measurement
 Subject: [Bulk] [time-nuts] There seems to be something missing from this 
 eBay item.
 
 I just cant figure out what it is ;)
 
 http://www.ebay.com/itm/HP-Agilent-5071A-Primary-Frequency-Standard-/191386439159?pt=LH_DefaultDomain_0hash=item2c8f854df7
 
 One obvious question: Are the leftover parts worth anything close to the 
 opening bid ?
 
 -George, N2FGX
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