Re: [time-nuts] End of Range Oscilloquartz 8600-3

[Christopher Hoover]

I got into the package out of the dewar of my FTS 1200-100 without breaking
it:

https://photos.google.com/share/AF1QipPxJF0Fn6_
gSjXQzk3OhoAhvgqizxmo4A41bIdyk8FrpkNIOfW5Q5feLwLsO4od8Q?key=
NmRRejU0eEYtVUQ4ZURTMnE4cXZEOWtIVmtQZTZB

-ch
73 de AI6KG


On Tue, Dec 12, 2017 at 3:50 PM, Magnus Danielson <
mag...@rubidium.dyndns.org> wrote:

> Hi Ed,
>
> Thanks for the pictures. I had to change the dewar flask on one of mine,
> so I saw about the same thing some 10 years ago or so, but memory.
> Didn't go all the way into the oscillator.
>
> The oscillator picture is mirrored.
>
> Cheers,
> Magnus
>
>
> On 12/12/2017 06:32 PM, Ed Palmer wrote:
>
>> It sounds like yours is different from my 8601.  How old is yours? From
>> the label inside it looks like mine is from 1983.
>>
>> Internal pictures are here:
>>
>> http://s701.photobucket.com/user/edpalmer42/library/Oscilloq
>> uartz%208601%20Oscillator
>>
>> If you click on 'view as story' you'll see some comments that I added to
>> the pictures.
>>
>> Ed
>>
>> On 2017-12-12 11:00 AM,   wrote:
>>
>>> Emailed Oscilloquartz that now has another name: Advaoptical... This in
>>> my capacity as aresearch engineer at Onsala Space Observatory.And the
>>> oscillator is at my work bench. Nothingprivate/hobby about this.
>>> The answer was that since we do not have a service agreement,they would
>>> not disclose any information.
>>> (Compare this with Keysight who has a free downlad area for oldmanuals.
>>> IMO the Keysight approach benifits their businessin the long term).
>>> So...
>>> I went along and started to dissassemble the 8600-3.
>>> The outer case was easy. Inside is a PCB with RF buffersand temperature
>>> regulation circuitry.
>>> Then there is a thermo bottle with the ovenized oscillator.This unit is
>>> connected to the PCB using two flex cables.
>>> The oscillator unit can simply be extracted from thebottle using an
>>> Metric 3 mm screw lightly screwed inone of the holes in the oscillator
>>> assembly.
>>> The assembly can be accessed by carfully unscrewingthe flex-cable end
>>> from the other mechanics. No needto touch the three small screws at the lid.
>>> Now it is starting to get intersting. I have not foundthe RF wiring into
>>> the crystal. The PCB in this unitseems to deal only with temperature
>>> regulation.Possibly, the RF is routed together with some heaterwinding.
>>> Or the crystal and the oscillator parts is sealedin such a way that
>>> there will be no wayto dissassemble it. There are several thermistorsglued
>>> inside to various parts of the oscillator/ovenassembly. That will make any
>>> further attemptsdifficult as the connecting wires are thin and delicateif
>>> they needs to be unsoldered.
>>> The construction is a nice piece of engineering.I'll give them that.
>>> Right now, I cannot see any typical oscillatorcircuitry (pF, nH, RF
>>> transistors) etc.
>>> I think I'll contemplate on the next movefor a day or so...
>>>
>>> Ulf Kylenfall
>>>
>>>
>>>
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Re: [time-nuts] Favorite counters (current production)?

[Christopher Hoover]

>
> When I saw how badly they handled the external REF-in


I (my company) have one of these.  Can you say more?

re: SRS, I ran into the CEO -- I have forgotten his name and misplaced his
card -- at a local office supply store in Mountain View near the end of
2016.  I was behind him in a long'ish xmas line.He was buying some
end-of-the-year payroll forms.  He was with his wife, and he or she said
something that made me realize that he was with SRS.   So I introduced
myself first as an engineer at a local tech company that knew of his
company and then as a time-nut (never lead with the time-nut thing :-)).  I
explained that I had a couple of SRS rubidium standards, and  that there
were a bunch of folks in our pro-to-hobby community who really liked the
SR620.  (Would you please offer me a xmas discount on an SR620, please, I
did not ask.)   Really nice guy.   SRS is a small company -- we chatted
about some of the challenges they faced.   I related that I could remember
doing payroll paperwork by hand once upon a time.

-- Christopher.
73 de AI6KG



On Sat, Nov 11, 2017 at 2:42 AM, Tom Van Baak  wrote:

> > Rank your preferences!
>
> I echo Magnus. In almost every photo of national timing labs you will see
> SR620's in use. The interface, specs, readability, and reliability are
> really good. Also SRS seems to support their products forever. For the
> curious, the full BOM and schematics are in the service manual. Note they
> just added the FS740 (GPSDO) but there's no update for the 620 after all
> these years. The downside is that they are larger, heavier, and louder than
> many modern instruments.
>
> For high-performance and high-throughput the CNT-91 is my choice. Quiet,
> feather-light, and it's a continuous dual-edge timestamping counter with
> raw data output capability.
>
> That said, when I need a quick or long-term measurement I almost always
> grab a HP 53132A and run it in talk-only mode, collecting data with
> RS232->USB. Once you get used to the 5 key (arrows & enter) UI you're all
> set.
>
> About the 53230 -- When it came out I got a pair on loan from Agilent; one
> with and one without OCXO. When I saw how badly they handled the external
> REF-in and how noisy the REF-out was, I figured it was a green team that
> designed it and I'd give them another product life cycle to learn about
> precision timing. So there are no 53230A in my lab. As soon as they come
> out with a redesigned B version where the ext/int REF are good to 1 ps
> (like you'd expect with a 12 digit/s counter), I will be the first to buy
> one.
>
> /tvb
>
> - Original Message -
> From: "Magnus Danielson" 
> To: 
> Cc: 
> Sent: Friday, November 10, 2017 11:50 AM
> Subject: Re: [time-nuts] Favorite counters (current production)?
>
>
> Hi,
>
> I would say CNT-99/91 and SR-620.
>
> Bob has a point about 53230, since the others is older, but on the other
> hand, it is a bit of a gamble. There are many aspects that goes into the
> longlivety of a product, such as access to components, but also strategy
> of companies.
>
> The CNT-90/91 an 53230 both have graphical presentation, which is very
> beneficial. The SR-620 still have better performance even being older
> than everything else.
>
> Cheers,
> Magnus
>
> On 11/10/2017 05:37 PM, Bob Camp wrote:
> > Hi
> >
> > There is no perfect answer. I’d go with the 53230 simply because it
> *might* be supported
> > the longest.
> >
> > Bob
> >
> >> On Nov 10, 2017, at 11:17 AM, Scott Newell 
> wrote:
> >>
> >> What current production freq counters do people like for general
> time-nuttery these days? There's a chance I can get a decent counter for
> work, so I'm looking for suggestions. Bonus points for fanless. Don't need
> anything past 200 MHz or so. Prefer ethernet over USB or GPIB.
> >>
> >> The SR620 looks to be pretty big and a little dated. The 53230A seems
> to have better specs and screen than the Tek/Fluke FCA3k series. Am I
> missing any?
> >>
> >> Rank your preferences!
> >>
> >> --
> >> newell  N5TNL
>
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Re: [time-nuts] Novatel Dual frequency GNSS receivers on ebay

[Christopher Hoover]

Tom,

Please see:

  https://www.novatel.com/assets/Documents/Manuals/om-2128.pdf

  https://www.novatel.com/assets/Documents/Manuals/om-2129.pdf


OEM628 and OEM638 boards can take an external frequency reference
(218/4.10.5), but OEM615 cannot.   I've never tried it.


To get the exact time of the PPS you need to enable the TIME message
(219/3.2.173) with something like (untested):

  LOG TIMEA ONTIME 1



A typical way to use the Novatel solution is to wire signals for the events
of interest -- say a camera shutter or start of frame (SOF) or a LIDAR
start of scan (SOS) -- into the receiver on one of the several event inputs.

With a suitable configuration, the log will contain messages with the
current 6-dof + time solution for the event edges.

If you are also logging the full receiver state, you can post-process the
events into better 6-dof + time solutions.



-- Christopher
73 de AI6KG








On Mon, Oct 9, 2017 at 1:02 PM, Tom Van Baak <t...@leapsecond.com> wrote:

> Christopher,
>
> Thanks for that additional information. Can you (or Gregory) also comment
> on the external frequency input / output and the 1PPS output of this
> receiver?
>
> A quick look at the om-2128.pdf and om-2129.pdf documents has
> words like "better than 250 ns accuracy" and "50 ns increments" but I
> didn't see mention of 1PPS quantization, sawtooth correction, or other
> words commonly used in GPS timing receiver specifications. I'm guessing
> this product is mostly designed for the PN part of PNT (Positioning,
> Navigation, Timing)?
>
> /tvb
>
> - Original Message -
> From: "Christopher Hoover" <c...@murgatroid.com>
> To: "Discussion of precise time and frequency measurement" <
> time-nuts@febo.com>
> Sent: Monday, October 09, 2017 12:35 PM
> Subject: Re: [time-nuts] Novatel Dual frequency GNSS receivers on ebay
>
>
> >I have quite a bit of experience with Novatel hardware include OEM6, CPT
> > and SPAN.
> >
> > CPT is an IMU made by KVH and relabeled by Novatel.The accelerometers
> > are MEMs and the roll rate sensors are FOGs.   Pretty old design.
> > Performance is decent (but not auto alignment good).
> >
> > http://www.kvh.com/Military-and-Government/Gyros-and-
> Inertial-Systems-and-Compasses/Gyros-and-IMUs-and-INS/IMUs/CG-5100.aspx
> >
> > SPAN is the "solution."SPAN-CPT puts the CPT IMU and the receiver in
> a
> > single box.   You could also get just the CPT in a box.
> >
> > The feature set enabled depends on the software keys that are loaded.
> > Caveat emptor.
> >
> > Dual receiver (even if you have the hardware) and ALIGN feature are extra
> > features.
> >
> > Also worth noting is that the circular connectors used on some of the
> > hardware are pricey.  Some are impossible to assemble without specialty
> > tools.
> >
> > -- Christopher.
> > 73 de AI6KG
> >
> >
> > On Sat, Oct 7, 2017 at 2:36 PM, J. L. Trantham <jlt...@att.net> wrote:
> >
> >> Any idea what they are selling for at this time?
> >>
> >> I see that some sold for the BIN price of $349.99 up until June 20.
> After
> >> that, 'Offer Accepted' occurred up through October 5, with a BIN price
> now
> >> of $649.99, all plus $40 shipping.
> >>
> >> Joe
> >>
> >> -Original Message-
> >> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of
> Gregory
> >> Maxwell
> >> Sent: Saturday, October 07, 2017 2:17 PM
> >> To: Discussion of precise time and frequency measurement
> >> Subject: [time-nuts] Novatel Dual frequency GNSS receivers on ebay
> >>
> >> There is an ebay listing for "Novatel GPS-702-GG with SPAN-CPT Single
> >> Enclosure GNSS/INS Receiver + Cable" with a fairly large number
> available.
> >>
> >> This is a Novatel OEM628 dual frequency receiver (supports GPS, Glonass,
> >> SBAS, apparently including L1C and L2C), plus a three fiber ring gyros
> >> (with bias performance that blows away any mems gyro I've ever used)
> and an
> >> 3-axis mems acceletrometer in an aluminum case, plus a decent dual
> >> frequency antenna.  This is a generation-ish old kit.
> >> The industrial casing conspires to make it look somewhat less modern
> than
> >> it actually is.
> >>
> >> The receivers have external clock input (though not plumbed to the
> outside
> >> of the case) which appears to work though I didn't try much with it yet.
> >> Mine came with 2013-ish firmware but easily upgraded to current (201

Re: [time-nuts] Novatel Dual frequency GNSS receivers on ebay

[Christopher Hoover]

I have quite a bit of experience with Novatel hardware include OEM6, CPT
and SPAN.

CPT is an IMU made by KVH and relabeled by Novatel.The accelerometers
are MEMs and the roll rate sensors are FOGs.   Pretty old design.
Performance is decent (but not auto alignment good).

http://www.kvh.com/Military-and-Government/Gyros-and-Inertial-Systems-and-Compasses/Gyros-and-IMUs-and-INS/IMUs/CG-5100.aspx

SPAN is the "solution."SPAN-CPT puts the CPT IMU and the receiver in a
single box.   You could also get just the CPT in a box.

The feature set enabled depends on the software keys that are loaded.
Caveat emptor.

Dual receiver (even if you have the hardware) and ALIGN feature are extra
features.

Also worth noting is that the circular connectors used on some of the
hardware are pricey.  Some are impossible to assemble without specialty
tools.

-- Christopher.
73 de AI6KG


On Sat, Oct 7, 2017 at 2:36 PM, J. L. Trantham  wrote:

> Any idea what they are selling for at this time?
>
> I see that some sold for the BIN price of $349.99 up until June 20.  After
> that, 'Offer Accepted' occurred up through October 5, with a BIN price now
> of $649.99, all plus $40 shipping.
>
> Joe
>
> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Gregory
> Maxwell
> Sent: Saturday, October 07, 2017 2:17 PM
> To: Discussion of precise time and frequency measurement
> Subject: [time-nuts] Novatel Dual frequency GNSS receivers on ebay
>
> There is an ebay listing for "Novatel GPS-702-GG with SPAN-CPT Single
> Enclosure GNSS/INS Receiver + Cable" with a fairly large number available.
>
> This is a Novatel OEM628 dual frequency receiver (supports GPS, Glonass,
> SBAS, apparently including L1C and L2C), plus a three fiber ring gyros
> (with bias performance that blows away any mems gyro I've ever used) and an
> 3-axis mems acceletrometer in an aluminum case, plus a decent dual
> frequency antenna.  This is a generation-ish old kit.
> The industrial casing conspires to make it look somewhat less modern than
> it actually is.
>
> The receivers have external clock input (though not plumbed to the outside
> of the case) which appears to work though I didn't try much with it yet.
> Mine came with 2013-ish firmware but easily upgraded to current (2016)
> firmware. There is a windows based firmware update tool which talks to it
> over serial and is very straight forward (The firmware update OEM6631.zip
> can be found via google).
>
> You can communicate with them over serial in ascii, there is extensive
> firmware documentation that goes over every command
> https://www.novatel.com/assets/Documents/Manuals/om-2129.pdf  some of
> which are specific to other modules. There is also a separate manual for
> the inertial navigation specific features (NovAtel SPAN-CPT Users
> manual.pdf)
>
> The external clock should allow you to hang it off a more stable
> oscillator which will improve the stability of the GNSS results, and _I
> presume_ improve the quality of the PPS output-- the firmware manual and
> operating manual are thin on details, and mostly just go into telling you
> how to adjust the kalman filter constants for different clock types.
>
> These also appear to support the novatel 'align' mode where you serial
> connect two receivers separated by a short baseline and get really accurate
> absolute headings; I'm planning on trying that that but haven't set it up
> yet.
>
> Looks like uber (last position was ubers offices in denver) had a fleet of
> these things. The couple I got run great, including the IMU, the antennas
> obviously spent a long time outside, but work fine. The cable they come
> with is weird, but I had no problem chopping one end off and figuring out
> the pinout (see bottom).
>
> The novatel OEM6 is well supported by rtklib and I was able to get
> post-processed positions very easily.
>
> Seller takes best offers a fair amount below the $649 asking price.
> Looks like they may have another 30 or so of them.
>
> May be useful for doing time transfer especially with the clock input.
> Just using it to get nice dual band observations to precisely survey an
> antenna location for a traditional GPSDO may improve GPSDO performance by a
> fair amount.
>
> Here is the signals and wire colors on the cables mine came with.
> YMMV, I'd suggest not blindly trusting that colors match on other
> units.These cables don't plumb out many of the signals from the
> module (in particular, they don't carrying COM2, which is why I haven't
> tried multi-receiver headings yet, since I'd need to figure out how to talk
> to it over USB if com1 is in use for that), I'm unsure if they're wired
> through the to external connector.
>
> 01 white  power return (-)
> 02 brown  9-18 VDC power input (+)
> 03 yellowCOM1 RS232 TX
> 05 pink   COM1 RS232 RX
> 09 green  COM1 GND
> 10 black  USB D+
> 11 purple USB D-
> 12 yellow 

Re: [time-nuts] Special connector for Symmetricom X72 rubidium standard

[Christopher Hoover]

I'm interested in a piece or two if you do this.   Happy to review
schematics and layout, too.  -- Christopher  AI6KG


On Tue, Aug 15, 2017 at 8:28 AM, Mark Sims  wrote:

> Symmetricom sold some interface boards for the X72.   They are 0.32-ish
> inch thick PCB's  with a dual sided edge tab pattern on them.   The PCB
> edge tab will insert into the connector on the X72.  The interface board
> for my X72's only breaks out 12 pins...  a lot of Ebay X72's come with that
> 12 pin connector board...  I think that they were pulls from some piece of
> equipment.   My X72's only had 250 hours on them.
>
> I have been thinking about laying out an X72 interface board that has the
> edge tab broken out to a standard 26 pin 0.1" pattern,  a RS-232 inteface,
> BNC's for the 10 MHz, ACMOS output,  1PPS in,  1PPS output, etc.  The board
> would also have a way to connect it to the SA22.
>
> Lady Heather now talks to X72's (and probably X99's and SA22's).   I have
> implemented a disciplining algorithm for use with X72s that have the older
> firmware that does not do disciplining... like probably 99% of the X72's
> out there.  Symmetricom's code only seems to keep the 1PPS aligned with 300
> ns.  My code attempts to keep it within 100 ns.
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[time-nuts] Can I haz an anti-hydrogen maser now?

[Christopher Hoover]

http://www.swansea.ac.uk/media-centre/latest-research/firstobservationofthehyperfinesplittinginantihydrogen.php
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Re: [time-nuts] WWV 25 MHz antenna switched to circular polarization

[Christopher Hoover]

On Jul 16, 2017 4:49 PM, "Brian, WA1ZMS"  wrote:

FWIW.We're at an 11 yr low for solar activity. Thus no big suprise that
25MHz is not covering the US very well, but a rare opening is always
possible.


+1 de ai6kg
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Re: [time-nuts] 5370B Question / help needed

[Christopher Hoover]

sorry, folks.  i meant to sent that directly to mark.

On Sun, Jul 2, 2017 at 3:49 PM, Christopher Hoover <c...@murgatroid.com>
wrote:

> HI Mark,
>
>
>> If you need to troubleshoot the unit, I have a few extender card kits
>> left... $30+shipping for the three board set.
>
>
> I'm interested.  Waht is the shipping to 94040 residential?
>
> Thanks,
> -ch
> 73 de AI6KG
>
> On Sat, Jul 1, 2017 at 1:23 PM, Mark Sims <hol...@hotmail.com> wrote:
>
>> This is a very common problem...  basically the fan blows directly down
>> the chassis onto the front panel area where a large dust bunny builds its
>> nest.  The switches are gold plated leaf springs that slide on a gold
>> plated circuit board.  They are open to the environment and collect all
>> sort of dust and schmutz.
>>
>> If you need to troubleshoot the unit, I have a few extender card kits
>> left... $30+shipping for the three board set.  Two 44-pin boards are used
>> to extend a card from the mainframe and there is a 36 (?) pin card that can
>> be used with the front panel or oscillator buffer card..
>>
>>
>> ---
>>
>> > One other observation, probably related: After powerup it took several
>> vigorous switch activations of the COM/SEP switch before the thing swung
>> into action at all
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>
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Re: [time-nuts] 5370B Question / help needed

[Christopher Hoover]

HI Mark,


> If you need to troubleshoot the unit, I have a few extender card kits
> left... $30+shipping for the three board set.


I'm interested.  Waht is the shipping to 94040 residential?

Thanks,
-ch
73 de AI6KG

On Sat, Jul 1, 2017 at 1:23 PM, Mark Sims  wrote:

> This is a very common problem...  basically the fan blows directly down
> the chassis onto the front panel area where a large dust bunny builds its
> nest.  The switches are gold plated leaf springs that slide on a gold
> plated circuit board.  They are open to the environment and collect all
> sort of dust and schmutz.
>
> If you need to troubleshoot the unit, I have a few extender card kits
> left... $30+shipping for the three board set.  Two 44-pin boards are used
> to extend a card from the mainframe and there is a 36 (?) pin card that can
> be used with the front panel or oscillator buffer card..
>
>
> ---
>
> > One other observation, probably related: After powerup it took several
> vigorous switch activations of the COM/SEP switch before the thing swung
> into action at all
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Re: [time-nuts] Power Connectors and D-Subs...

[Christopher Hoover]

>
> I’m not claiming Lemo’s are any cheaper or easier to get than the uber
> D’s. At least they
> give a bit better density.


we are in violent agreement.


On Mon, Jun 26, 2017 at 7:06 PM, Bob kb8tq <kb...@n1k.org> wrote:

> Hi
>
> I’m not claiming Lemo’s are any cheaper or easier to get than the uber
> D’s. At least they
> give a bit better density.
>
> Bob
>
> > On Jun 26, 2017, at 9:19 PM, Christopher Hoover <c...@murgatroid.com>
> wrote:
> >
> > On Sun, Jun 25, 2017 at 2:53 PM, Bob kb8tq <kb...@n1k.org> wrote:
> >
> >> Hi
> >>
> >> Cost a fortune *and* can easily get you into 12 week delivery times ….
> >>
> >
> > oh lord.  tell me about it.
> >
> > we need to put lemo's in the same bucket -- expensive and long lead
> times.
> >
> > (they are so expensive there are counterfeits.  really good looking
> > counterfeits, yes, but oversize.)
> > ___
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Re: [time-nuts] Power connectors continued

[Christopher Hoover]

>
>  They will definitely not work loose.


ODU or Glennair (I forget which) has a ratcheting lock ring on some of
their connectors.  It has asymmetric ramps on the ratchet cam that tighten
the lock ring under vibration.

-ch
73 de AI6KG


On Fri, Jun 23, 2017 at 9:01 PM, Charles Steinmetz 
wrote:

> Someone previously mentioned "aviation" style connectors (which many will
> recognize as mobile microphone connectors) (see graphic below).  I switched
> to these for power and other connections long ago, and have been extremely
> happy with them.
>
> One nice thing about them (IMO) is that all chassis connectors are male,
> and all cable connectors are female (unless you use a male in-line
> connector to make an extension cable).  This means that a dangling cable
> will never have rudely exposed contacts, and if you are really worried you
> can use vinyl caps to make sure.  Similarly, the pins on the male chassis
> connectors are well recessed so it isn't easy to short them, but if you
> want to be sure you can get screw-on caps (see below).
>
> The contacts have substantial tension when mating/mated, plus secure
> threaded locking rings.  They will definitely not work loose.  They will
> handle at least 5A per pin, and I've seen published ratings of 10A. They
> have good strain reliefs, too.
>
> They are available in a wide range of pin counts, so it is easy to make
> sure cables are not cross-compatible.
>
> One really nice feature is the availability of right-angle in-line
> connectors, to minimize the space needed behind equipment (this can be
> problematic with some other connector series).  Use many connectors and you
> will find that this can be an extremely valuable feature.
>
> On ebay, they are known as "aviation connectors," and are available in
> three sizes (12mm, 16mm, and 20mm, according to the diameter of the bodies,
> which is also the hole size for the chassis-mount connectors). Search for
> GX12, GX16, and GX20.  I have standardized on the 16mm version, but have
> tried and can recommend them all.  Shop a little and you will find them at
> very attractive prices.
>
> I've bought lots of them, from US and foreign suppliers, and as far as I
> can tell they all come out of the same factory in China.  All good quality.
>
> Best regards,
>
> Charles
>
>
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Re: [time-nuts] Power Connectors and D-Subs...

[Christopher Hoover]

On Sun, Jun 25, 2017 at 2:53 PM, Bob kb8tq  wrote:

> Hi
>
> Cost a fortune *and* can easily get you into 12 week delivery times ….
>

oh lord.  tell me about it.

we need to put lemo's in the same bucket -- expensive and long lead times.

(they are so expensive there are counterfeits.  really good looking
counterfeits, yes, but oversize.)
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Re: [time-nuts] Name of integral of timing residual

[Christopher Hoover]

+1 to abtime


On Thu, Apr 20, 2017 at 1:35 PM, Tom Van Baak  wrote:

> Jim Palfreyman writes:
>
> > Consider a plot of a timing residual vs time. Say a watch against a
> maser,
> > residual=watch-maser.
>
> We usually don't use the word residual for this. When you compare a watch
> with a maser, or any DUT time against REF time, you get a quantity like:
> phase difference, or sometimes just "phase", or time difference, time
> error, time interval, time interval error, etc.
>
> What residual usually refers to is if you post-process the raw time or
> frequency data in some way to better expose underlying structure. For
> example, if you remove a linear or quadratic fit from your phase data the
> resulting data set can be called phase residuals. This is done with
> free-running clocks because both frequency, and especially phase, diverge
> badly over time. So plotting residuals removes large systematic effects and
> exposes small effects of interest.
>
>
> > Now if I now plot the cumulative sum (think integral) of the residual,
> > that's going to give me an overall view of how the clock is performing
> over time.
>
> A traditional phase plot of residuals is itself "an overall view of how
> the clock is performing over time". That's why even before we make ADEV
> plots we want to see the phase (actually, phase difference) plot and maybe
> also the frequency (usually, normalized frequency) plot. Both give an
> overall view of how the clock is performing, not to mention the ADEV plot
> which even further summarizes clock performance.
>
> A cumulative sum, an integral, of the timing residuals is a bit odd, but
> not wrong. This is the "area under the curve" of any residual phase plot. A
> traditional phase plot gives you a series of points on a line -- these tell
> you your clock error as a function of elapsed time. But plots are 2D, so
> your eye also senses the amount of area under the line -- this tells you
> not only how far off your clock is, but how long your clock has been how
> far off. The plot shows, and the eye recognizes both the line (how far) and
> the area (how far x how long).
>
> > (If it helps, think of PID controllers and how they work in the "I"
> part.)
>
> Yes, exactly. And the reason this is explicit in PID (or PIID) is that
> there is no human eye and no 2D plot. Therefore the PID algorithm has to
> manually compute the "area under the curve"; it has to calculate the
> cumulative sum as a scaler value. And it sounds like this single scaler
> value, as opposed to a rendered plot image, is what you're after.
>
>
> > Now if you look at *motion* of an object over time, and you integrate its
> > acceleration you get velocity, integrate again you get displacement.
> > Integrate again and you get "absement" and again you get "abcity" (I only
> > recently discovered these terms).
>
> Ok, thanks for that word of the day! Full list here:
>
> https://en.wikipedia.org/wiki/Absement#Higher_integrals
>
> > Does the integral of a timing residual have a name, and does the integral
> > of *that* have a name as well?
>
> Nope. But let's make one up in honor of your time spent doing Pulsar work.
> Some sources suggest absement is a portmanteau of absent and displacement.
> Ok, could be, but just as likely ab- is a fine Latin prefix on its own,
> meaning away, depart. Think of abnormal, abhor, absent, abdicate, aberrant.
> Or the German abfahren, to depart from. (Ah, I finally got to put my Latin
> and German to use; or is that abuse).
>
> https://en.wiktionary.org/wiki/ab-
> http://membean.com/wrotds/ab-away
> https://www.vocabulary.com/lists/135086
>
> Anyway, in the world of space / distance:
>
> -4 abserk
> -3 abseleration
> -2 absity
> -1 absement
>  0 displacement
> +1 velocity
> +2 acceleration
> +3 jerk
>
> So how about for the world of time, we call integrated phase error:
> abtimer, or just abtime:
>
> -1 abtime (integrated phase error, cumulative sum of time error, etc.)
> units: s^2
>  0 time (phase, time error, phase difference, etc.) units: s
> +1 frequency (rate of phase change, etc.) units: /s, Hz
> +2 drift (linear frequency change) units: /s^2, Hz/s
>
> I can imagine cases where abtime would be useful, especially for closed
> loops. Units are seconds^2, or second*days, etc. For example, it may come
> in handy when I post plots of the new WWVB receiver, or characterizing a
> sloppy GPSDO timing receiver.
>
> /tvb
>
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Re: [time-nuts] Spirent STR4500 GPS simulator

[Christopher Hoover]

I would check if the instrument contains a  FDTI USB to serial converter
part with a custom VID/PID.   That's a common trick.   That's trivial to
work around, at least on Linux.

-ch
73 de AI6KG


On Wed, Apr 5, 2017 at 1:05 PM, Bob kb8tq  wrote:

> Hi
>
>
>
>
> > On Apr 5, 2017, at 1:36 PM, Magnus Danielson 
> wrote:
> >
> > Hi Phil,
> >
> > I just wanted to chime in an make a note that the STR4500 seems to have
> USB connection rather than serial. The manual mentions installing a driver.
> I wonder if the USB port is nothing but a glorified serial port.
> > When you hook it up, what does your computer report? You should be able
> to get some info that way. If so, finding the 4100 manual that Bob
> mentioined was not too hard, and banging away on those commands where not
> too complex by the looks of it.
> >
> > Tempted.
> >
> > Cheers,
> > Magnus
>
> That would be yet another layer of problem. The Spirent guys used custom
> USB drivers for their devices. At least that is true for the boxes I have
> seen. They stopped issuing drivers for the 6100 with XP. I have no idea
> when they dropped drivers for the 4500. It’s a pretty good bet that you
> will need one ….
>
> Bob
>
>
> >
> > On 04/05/2017 03:46 PM, paul swed wrote:
> >> Phil
> >> Welcome to the group.
> >> Funny you mention the Spirent. I see many available for semi reasonable
> >> pricing though for Ham/Time-nuts a bit pricey still at $295 for a
> tinkerer.
> >> And they do not come with the disk.
> >> But as was pointed out to me by a fellow time-nut you don't need it. You
> >> can directly control the unit by rs232 through quite simple commands.
> Use a
> >> USB to RS232 converter if you do not have a real port.
> >> You can create batch files of the comands on and on. I had downloaded
> the
> >> manual to look at.
> >> However I will not be buying a unit for quite a long time. Would need
> to be
> >> sub $100 for me at least.
> >> Good luck and have fun.
> >> Regards
> >> Paul
> >> WB8TSL
> >>
> >> On Wed, Apr 5, 2017 at 6:24 AM, Phil Parsons <
> p...@computerhotline.co.uk>
> >> wrote:
> >>
> >>> This is my first post after lurking for quite a while reading & trying
> to
> >>> get to grips with the technology. I just purchased a Spirent STR4500
> GPS
> >>> simulator  along with a pile of other kit. Unfortunately the CD was
> missing
> >>> (no great surprise) & Spirent are not interested in selling me a
> >>> replacement disk. So, can anyone help me with software for this or
> should I
> >>> accept it is  a door stop & get rid? My plan was to use this to get
> >>> consistent signals to test a few GPSDOs I have acquired. Any advice
> >>> gratefully received.
> >>>
> >>> Phil
> >>> ___
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> >>>
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[time-nuts] TDC-GPX2 TDC chip

[Christopher Hoover]

http://ams.com/eng/Products/Precision-Time-Measurement/Time-to-Digital-Converters/TDC-GPX2

Claims to have single-shot accuracy of 10 ps.
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[time-nuts] 33120A purchase off epay

[Christopher Hoover]

My HP 33120A Function Generator died. (I'm still trying to fix it, but it
isn't obvious what's wrong ... rails check so I'm suspicious the EEPROMs
gave up the ghost.)

I bought a new one on epay week befor last for a fair price.

It arrived and I was surprised/excited to find it had the external
reference option. Just what a TimeNut needs.

The external ref option wasn't mentioned explicitly in the listing,
although I can see it (in retrospect) in one of the pictures.

Sweet!

-- Christopher.
73 de AI6KG
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Re: [time-nuts] TTimelab question

[Christopher Hoover]

One way to do cheap, short-run enclosure costs is to use extruded aluminum
cases of this sort
.
They extrusion only needs to be cut to length.   It is completed with a
front and back panel that is just a simple stamping or lasering of sheet
metal.   You get a lot of pieces out of one sheet.   Add optional silk
screening.

For full stamped and braked enclosures, I've gotten quite decent prices
from United Sheet Metal for short runs (100's).   They often send the job
to Taiwan.

Protocase is good for 1-10 pieces.

-ch




On Wed, Feb 22, 2017 at 6:13 AM, John Ackermann N8UR  wrote:

> I really like the setup that Mark is describing.  As to TAPR's plans,
> we've found that enclosures are a challenge -- metalwork is pretty
> expensive unless you get significant volume, and in our niche market,
> that's hard to do.
>
> But I am hoping to find an inexpensive clamshell-type enclosure with flat
> front and rear panels, and then do up designs (perhaps with Front Panel
> Express) for those panels.  That can be done at a reasonable cost, and at a
> minimum we can make design files available so people can order their own
> panels.
>
> For my own use, I'm also going to do a couple of 2U rack enclosures -- one
> to hold two TICCs operating independently, and another for the "megaTICC"
> -- four units slaved together to make an 8 channel counter, with a
> Raspberry Pi controller along the line of what Mark described. (In
> multi-board mode, each TICC outputs on its own USB line, so the RPi's main
> purpose is to deal with the 8 channels of data from 4 USB connections.)
>
> I'll make the design files for those enclosures available as well, but it
> may be a while as my entire lab is now packed up as we are in the final
> stages of moving from Atlanta back to Dayton.
>
> Also, in a day or three I'll be announcing a simple project that sprung
> out of the TICC assembly and testing process that some of you might find
> useful.  We're still finalizing details on that.
>
> John
> 
>
> On 02/21/2017 11:45 PM, Mark Sims wrote:
>
>> I doubt that it is something TAPR would do.   Building complete systems
>> gets into all sorts of issues (mainly regulatory).   But it is easy enough
>> to build.   They sell a nice case that the RPI3 and touchscreen mounts in.
>> The PI+touchscreen+case sells for around $110.   The TICC(s) connect to it
>> via USB.
>>
>> There are also some Win10 tablets with 1024x600 touch screens that sell
>> for around $60 (apparently Microsoft doesn't charge manufacturers for Win10
>> on tablets with small/low res screens).
>>
>> I  am thinking about laying out a front-end board for the TICC.  It would
>> have some switchable (relay?) 50 ohm input terminators,  switchable PICDIV
>> dividers for PPS/1MHz/5MHz/10MHz/15MHz (or 2.5 MHz)  inputs,  footprints
>> for a decent reference oscillator (MV89/8663/DIP/etc), and a 12V to 5V
>> (3A?) power converter for the  TICC and PI... most of the better surplus
>> oscillators run off of 12V.  Also maybe add a data multiplexer for
>> combining the outputs of two TICC boards into one data stream (but Heather
>> could do that in software).  John has some ideas for a similar board.
>>
>> -
>>
>>   Wow!  If you can persuade John and TAPR to produce that, I would be
>>> there
>>>
>> with my chequebook before the ink had dried on the web-page! :-)
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Re: [time-nuts] ``direct'' RS-232 vs. RS-232 via USB vs. PPS decoding cards

[Christopher Hoover]

>
> The Intel guys have some *very* fast timers flying around their cpu’s.
> They would laugh
> at the idea of a 10 or 100 MHz clock. If you can configure the pin to grab
> the data off those timer, you
> have way better than 100 ns at the timer.


We're most certainly getting off topic, but the errata on TSC [1] and HPET
[2] are long and  mostly not public.   There be dragons with DVFS [3] and
power/idle states.

On Linux you can tell what you have available and what you are using by
looking in /sys/devices/system/clocksource/clocksource0, e.g.

ch@asus-ch:~$ cat
/sys/devices/system/clocksource/clocksource0/available_clocksource tsc hpet
acpi_pm ch@asus-ch:~$ cat
/sys/devices/system/clocksource/clocksource0/current_clocksource tsc
ch@asus-ch:~$

Linux usually disqualifies egregiously bad clock soureces.

-christopher
73 de AI6KG


[1] https://en.wikipedia.org/wiki/Time_Stamp_Counter
[2] https://en.wikipedia.org/wiki/High_Precision_Event_Timer
[3] https://en.wikipedia.org/wiki/Dynamic_voltage_scaling




On Fri, Feb 17, 2017 at 4:48 PM, Bob Camp  wrote:

> Hi
>
> Roughly speaking, if you have a 10 MHz clock driving a timer and the pin
> latches data
> from that timer, you get 100 ns “buckets and +/- 100 ns “jitter”.  You can
> find MCU’s that
> will do this for < $1. If you go crazy, you can spend < $10 and still get
> a very fancy MCU
> on a board with all the support “stuff”. That would get you into > 100 MHz
> clocks driving
> counters that might be 32 bits wide.
>
> The Intel guys have some *very* fast timers flying around their cpu’s.
> They would laugh
> at the idea of a 10 or 100 MHz clock. If you can configure the pin to grab
> the data off those timer, you
> have way better than 100 ns at the timer. The trick is writing a driver
> that does that. How
> easy that is to do depends a *lot* on your OS and the chipset you are
> running. It may
> be trivial or it may be impossible.
>
> At some point one might ask: Is a $1 MCU a “system” or is it a peripheral?
>
> Bob
>
>
> > On Feb 17, 2017, at 5:58 PM, Thomas Petig  wrote:
> >
> > Hi,
> >
> > I was wondering whether there is some data/information available on the
> > claimed +/- 100 ns jitter?
> >
> > Regarding the PPS -> USB (using the CTS line of a FTDI FT232R), I
> > plotted, using some lines of Python, the time offset as attached. Just
> > to get an overview how it is 'worst case', i.e., user program, python,
> > etc. The 1PPS signal comes from a GPS rx.
> > Looks like a standard deviation of around 150 us.
> > y-axis:  measured pps offset from full second (computer time) in us,
> > x-axis pps pulse number.
> >
> > On the long term it looks interesting (while measuring I played with the
> > NTP server on this computer)
> > Until ca. second 1: ntpd synchronization via internet
> > Until ca. second 17000: made an additional LAN NTP server (GPS) available
> > Until the end: replaced ntpd with chrony (still using internet and local
> > servers)
> >
> > Interesting points:
> > -It looks surprisingly bad with using the normal ntpd (especially, there
> > is not really an improvement having an local GPS based server
> > available, did I do something wrong? Only the offset changes by ca. 3
> > ms.)
> > -It looks surprisingly good with chrony. But there are continuously
> > outliers of up to 4500 us, is this a result of the chrony control loop?
> > The time is wandering around with ntpd, but has less jitter.
> >
> > Conclusion:
> > Despite the 150 us stddev, the using PPS over USB gives some interesting
> > inside of what the local ntp server is actually doing. It looks to me
> > like it would be an improvement to use it when using ntpd, but not when
> > using chrony.
> >
> > Best regards,
> >   Thomas
> >   DK6KD
> >   SA6CID
> >
> > PS:
> > Raw data is here, if you want to zoom in: (1.7 MiB, one row per PPS
> > offset in us)
> > http://petig.eu/pps-usb.txt
> >
> > On Tue, Feb 14, 2017 at 07:26:23AM -0500, Bob Camp wrote:
> >> Hi
> >>
> >> A direct port might be a +/- 100 ns sort of thing most of the time and
> a +/-10 us
> >> thing every so often under some OS’s. Most desktop operating systems
> are not
> >> designed to prioritize random pin interrupts. A dirt cheap MCU coded
> with a few
> >> (hundred) lines of assembly code may be a better option than a typical
> desktop.
> >> Complicating this further is the degree to which some OS’s can be
> directly or
> >> indirectly optimized. Install *this* package and it all goes nuts.
> Install that package
> >> and not much happens ….
> >>
> >> Bob
> >>
> >>> On Feb 13, 2017, at 11:07 AM, Ruslan Nabioullin 
> wrote:
> >>>
> >>> Hi, generally speaking, what are the performance differences between
> the following: 1. direct RS-232 (i.e., what I believe is a standard PCI
> card offering RS-232---essentially UARTs interfaced more-or-less directly
> to the PCI bus); 2. RS-232 via USB; 3. PPS decoding PCI cards (which might
> also have an IRIG input or even 

Re: [time-nuts] ``direct'' RS-232 vs. RS-232 via USB vs. PPS decoding cards

[Christopher Hoover]

On Thu, Feb 16, 2017 at 10:42 AM, Christopher Hoover <c...@murgatroid.com>
wrote:

> Ntp has support to pick up hardware packet timestamps from the Linux
> kernel.   I wrote the patch; it was merged years ago.
>
>
I'm wrong about this.

The patch I wrote added support for SO_TIMESTAMPNS (see [1]).With
SO_TIMESTAMPNS, the kernel puts the timestamp on the packet just after the
driver hands it to the receive path.

There's a newer interface, SO_TIMESTAMPING, for access to NIC hardware
timestamps.There's no support it on the ntp head for this AFAICT.
 The necessary patch looks straightforward, but I don't think I have the
hardware to test it.

-- Christopher
73 de AI6KG.

[1] https://www.kernel.org/doc/Documentation/networking/timestamping.txt



-c73 de AI6KG
>
>
>
> On Thu, Feb 16, 2017 at 9:59 AM, Denny Page <de...@cococafe.com> wrote:
>
>> If your Ethernet chipset (mac or phy) has timestamping capabilities, you
>> can use Chrony which has hardware timestamp support. This greatly improves
>> accuracy, and generally eliminates the CPU loading issue.
>>
>> Denny
>>
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Re: [time-nuts] ``direct'' RS-232 vs. RS-232 via USB vs. PPS decoding cards

[Christopher Hoover]

Ntp has support to pick up hardware packet timestamps from the Linux
kernel.   I wrote the patch; it was merged years ago.

-ch
73 de AI6KG


On Thu, Feb 16, 2017 at 9:59 AM, Denny Page  wrote:

> If your Ethernet chipset (mac or phy) has timestamping capabilities, you
> can use Chrony which has hardware timestamp support. This greatly improves
> accuracy, and generally eliminates the CPU loading issue.
>
> Denny
>
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Re: [time-nuts] Sub-ps delay line

[Christopher Hoover]

is it possible to run each ADC using whatever phase of the common clock you
have,  measure the local phase differences between ADC's periodically, and
then work out the necessary sample offsets for the ensemble in software?

this ought to be more robust than trying to hold everything fixed over long
time and wide temperature.  (you'd still want to minimize excursions, of
course.)

-- christopher
73 de AI6KG


On Wed, Feb 8, 2017 at 3:25 AM, Mattia Rizzi  wrote:

> Hello,
> thank you all for the answers!
>
> The description I gave in the first email is a simplification of the
> system. The delay line is used to phase-match the clocks of a distributed
> measurement system. Each board feature an ADC and a DAC. You can see it as
> a distributed RF acquisition system, with microwave requirements on phase
> matching. The delay line is used ALSO to correctly align the clocks for the
> ADCs, since each IC has an unknown Aperture Delay (PVT kicks in).
> Unfortunately I cannot change the voltage references to introduces a
> variable delay. That's also why I would like to have a delay line rather
> than a set-and-forget solution: I can compensate for PVT of the ADC and DAC
> as well.
>
> About temperature variation: LTC6957-1 is excellent, 0.1ps/C of propagation
> delay change. I still have to check with Linear if this figure is valid
> also if you don't use BOTH (P and N) output clock lines. I'm not sure to
> use a balun (such as Minicircuit ADT2-1) for differential-to-single-ended
> conversion because I dont want to introduce additional tempco.
> Unfortunately, Mini-circuit has no data about that. The varactor itself has
> a slight tempco, but the overall tempco should be below 1 ps/C.
>
> About voltage & supply variations: I'm planning to use a dedicate LDO for
> the delay line. LTC6957-1 has a maximum of 50ps/V propagation delay
> variation, I'm expecting to use an LDO with  <1 mV/C of regulation
> stability (LT3045 has less than 100uV over 20 degree variation, but it's a
> bit expensive). Again, I don't know if the 50ps/V figure is still valid
> using only one output, but since LVPECL output stages are done using a BJT
> always in the active region, I'm expecting an isolation from the power
> supply voltage.
>
> @Magnus:
> >My first thought would be to use a pair of couplers before and after the
> delay line and bring it into a mixer to serve as a phase detector such that
> you can create a control loop to stabilize delay. This way you get a handle
> on the temperature variations.
>
> Thanks! Do you know a phase detector with such requirements on stability? I
> checked Mini-circuit but they don't have factory data on the stability of
> their products. Also, my signals are clocks rather than pure sinewaves.
>
> @Scott
> >I would also advise you take a look at how well you can maintain your
> system impedance, say 50 Ohms.  For example, I have seen about 100's ps
> phase difference on a 10 MHz reference, using one BNC female-female coupler
> versus another
>
> Yes, this is a calibration issue (repeatability) to be investigated, but
> since microwave systems have the same issues I hope there's already a way
> to how achieve that.
>
> Thank you!
>
> cheers,
> Mattia
>
>
>
>
>
> 2017-02-07 23:43 GMT+01:00 Magnus Danielson :
>
> > Hi,
> >
> > My first thought would be to use a pair of couplers before and after the
> > delay line and bring it into a mixer to serve as a phase detector such
> that
> > you can create a control loop to stabilize delay. This way you get a
> handle
> > on the temperature variations.
> >
> > There is trombone delays that can be used. They seem to reach that level
> > of resolution.
> >
> > There is microstepper boxes, but usually they operate on 5 or 10 MHz.
> >
> > There is multiple ways to design delays for CW signals, microsteppers
> uses
> > various forms of gear-boxes and programmable generators. Chips either use
> > gate delays or programmable comparator vs. ramp of some form.
> > Ensuring temperature stability and drift limits is however always an
> issue.
> >
> > Delay loop oscillator for calibration can be done, but biases can be
> > problematic, so a number of different setups needs to be done to build
> > confidence. It's a combinatorial exercise which is quite interesting.
> >
> > Cheers,
> > Magnus
> >
> >
> > On 02/07/2017 05:13 PM, Mattia Rizzi wrote:
> >
> >> Hello,
> >> I'm looking/designing a sub-ps delay line with very high stability.
> >> Basically it has microwave requirements on phase matching.
> >> The main features that such delay line should have are:
> >> - sub-ps resolution and about 1 ns range
> >> - High stability, must not drift more than 2ps/year, preferably 1ps/year
> >> - Temperature coefficient (tempco) below 1 ps/celsius
> >> - Low phase noise floor, target random jitter below 100 fs RSM from
> 100Hz
> >> to 1MHz.
> >> - flicker noise below -90dBc at 1Hz (100MHz carrier)
> >> - cheap (below 50 euros) and 

Re: [time-nuts] Reproducibility of position data from multiple surveys of HP 58503A GPS receiver

[Christopher Hoover]

My 58503A was showing an alarm when I came into the shack this morning.
(I forgot to jot down the text on the display.)  I cleared the alarm
(Shift-Alt) and it otherwise seems 100% happy.

-ch
73 de AI6KG

On Sun, Jan 1, 2017 at 7:02 AM, Dr. David Kirkby - Kirkby Microwave Ltd <
drkir...@kirkbymicrowave.co.uk> wrote:

> I put my HP 58503A into an infinite loop where
>
> 1) Forced GPS receiver to do a survey (GPS:POS:SURVEY ONCE)
> 2) Waited until survey was complete (GPS:POS:HOLD? returns 1)  This takes
> about 2 hour.
> 3) Recorded date (SYST:DATE?), time (SYST:TIME?) and location (GPS:POS?)
>
> For about 4 hours before the leap second, I stopped this, so the clock was
> right at the time of the leap second. Then I restarted some time after
> midnight.
>
> The actual data file is here
>
> http://www.kirkbymicrowave.co.uk/HP-58503A/gps.log
>
> which is being updated whenever a survey is complete, and new data
> collected - about once every 2 hours.
>
> A plot of the height from the first 19 data points is here.
>
> http://www.kirkbymicrowave.co.uk/HP-58503A/gps-height.pdf
>
> Unlike hte log, this is not being updated dynamically - I should have used
> another machine which has gnuplot on it for that.
>
> Anyway, based on the first 19 data points, the antenna height appears to
> be anywhere from 40 to 48.5 m. I'm pretty sure it is not bouncing up and
> down 8.5 metres! The latitude and longitude move too. I've not converted
> them into metres, so I don't know how much they represent.
>
> The antenna is about 3.5 m above ground level, mounted to the side of a
> garage, which is higher. I could push it another 2 m or so by mounting it
> on the garage, but not without drilling holes in the garage which will not
> exactly make the XYL happy, although I guess if I do it when she is not
> looking, its a bit late to moan then!
>
> I was thinking of telling the receiver the location is an "average" of the
> data points. Some thought would need to be given to averaging, although I
> would have thought in my latitude (51 deg, 39' N), and distance from the
> meridian (0 deg, 41' E), a simple mean would not be a bad figure. But I
> stand to be corrected.
>
> --
> Dr. David Kirkby Ph.D CEng MIET
> Kirkby Microwave Ltd
> Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Essex, CM3
> 6DT, UK.
> Registered in England and Wales, company number 08914892.
> http://www.kirkbymicrowave.co.uk/
> Tel: 07910 441670 / +44 7910 441670 (0900 to 2100 GMT only please)
>
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Re: [time-nuts] pcb protos

[Christopher Hoover]

+1 on Sunstone
+1 on Screaming Circuits, who will SMT the board with  consigned parts or
even do a full turnkey build.   Been happy with them on both accounts.

I don't know how many of these super cheap places will do full electrical
check  -- I want it on my personal boards.



On Fri, Dec 9, 2016 at 1:22 PM, jimlux  wrote:

> On 12/9/16 1:02 PM, Brooke Clarke wrote:
>
>> Hi John:
>>
>> Yes.  It is not at all economical to have ExpressPCB make boards the
>> final size in production.  BUT . .
>>
>
>
> I've used Sunstone (also known as PCBExpress, which *is* a bit confusing).
>
> both ExpressPCB and Sunstone also have deals with Screaming Circuits, who
> I've also used.
>
>
> Sunstone (like other places) can turn 2,4,6 layer boards around in a day,
> if you need it.  They can do up to 14 layers, although I've never used them
> for this, and I'll bet the lead time is a bit more
>
> They can also do boards on Rogers materials, if you're doing microwave
> stuff.
>
>
> There's a sort of hotbed of these quick turn firms up in Oregon.. I don't
> know why.
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Re: [time-nuts] TICC Timestamping / Time Interval Counter -- Available to Order

[Christopher Hoover]

Thanks, John!Just ordered two and looking forward to receiving it.  73,
Christopher de AI6KG

On Wed, Dec 7, 2016 at 11:45 AM, John Ackermann N8UR  wrote:

> I'm happy to report that TAPR is now accepting orders for the TICC
> timestamping / time interval counter.  We've placed an order with the
> contract manufacturer and expect to have finished product ready to ship
> sometime in February.  The TICC system will include the TICC shield mounted
> on an Arduino Mega 2560 compatible processor, with TICC software loaded.
> Each system will be tested for function before shipping.
>
> As I mentioned in my original email, TAPR is going a bit out on a limb to
> produce the TICC, and we have to make a significant up-front payment to our
> contract manufacturer. So, early orders are very much appreciated to help
> recover our cash flow.
>
> The regular price will be $190 each for the TICC shield with Arduino
> compatible processor,* but to encourage early orders, we're offering a $10
> discount for orders placed on or before December 21 -- that makes the price
> $180 plus shipping.
>
> You can order from: http://tapr.org/kits_ticc.html
>
> Thanks!
> John
>
> * We will provide a Sainsmart version of the Arduino Mega 2560 R3.  They
> seem to be a reliable supplier and we used these boards for TICC
> development.
>
>
>  Forwarded Message 
> Subject: [time-nuts] New Timestamping / Time Interval Counter: the TICC
> Date: Wed, 23 Nov 2016 10:48:57 -0500
> From: John Ackermann N8UR 
>
> Counters with resolution below 1 nanosecond are difficult.
> They require either outrageous clock speeds, or interpolators
> that are typically a bunch of analog components mixed with black
> magic and stirred by frequent calibration.  The very best single-shot
> resolution that's been commercially available is 20 picoseconds in
> the Keysight 53230A and HP 5370A/B.  My 5370B has an one-second
> noise ADEV of about 4x10e-11.
>
> With the help of some very talented friends, I've been working on a new
> counter called the "TICC" with <60ps resolution and similar jitter,
> based on the Texas Instruments TDC7200 time-to-data-converter chip. The
> one-second noise ADEV is about 7x10e-11, not much worse than the 5370,
> but here's the trick:  the TICC is an Arduino shield (mounting on a
> Mega 2560 controller) that weighs only a couple of ounces, requires
> *no* calibration, and is powered from a USB cable!
>
> The TICC is implemented as a two-channel timestamping counter.  That
> means it can measure one or two low-frequency (e.g., pulse-per-second)
> inputs against an external 10 MHz reference, or it can do a traditional
> time interval measurement of one input against the other.  It can also
> measure period, ratio, or any other function of two-channel  timestamp
> data.  (And by the way -- multiple TICCs can be connected to yield 4,
> 6, 8, or more synchronized channels, though we haven't tested this
> capability yet.)
>
> I've attached a picture of the TICC prototype as well as an ADEV plot
> of a 17+ day run of multiple measurements taken by two TICCs, and also
> showing the TICC noise floor.  The good news behind that plot is that
> there are more than 6 million data points behind these results, and
> there was not a single glitch or significant outlier among them.
>
> There's more information available at http://febo.com/pages/TICC
>
> The software is open source (BSD license) and is available at
> https://github.com/TAPR/TICC -- the current version seems be reliable
> but there are still features to add and a *lot* of cleanup to do; it's
> currently ugly and very much a work in process.
>
> As always, I'll be making the TICC available through TAPR.  We're still
> finalizing details, but we expect the price to be less than $200 for a
> turn-key system:  TICC mounted on an Arduino with software loaded and
> tested for basic functionality.  We hope to ship the TICC by February.
>
> I'll post a note in a week or two with final price and ordering
> information.  As a heads up, we will probably offer a small discoun
> for pre-orders.  TAPR is a shoestring non-profit group and the up-front
> cost to manufacture this unit will frankly be a challenge for us.
> Getting pre-orders will help our cash flow significantly, so we ask you
> to keep that in mind.
>
> John
>
>
>
>
>
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[time-nuts] TDC7201

[Christopher Hoover]

TDC7201 appears to be the same as the TDC7200 except that there are two
synchronized TDC cores and each TDC core has two extra "coarse" bits.

The eval board for TDC7201 (p/n TDC7201-ZAX-EVM) is $75.   You need a ~$25
MSP430 baseboard to make it go.

-christopher
73 de AI6KG
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Re: [time-nuts] Inside of FT1200-100

[Christopher Hoover]

OK, I think this folded-over cap sets the nominal XO frequency:

(link in case it doesn't go through: https://goo.gl/photos/XHUCKTnC3NAB5rKD6
)

I read the p/n as CY06C240J.   24 pFs?  CGW would seem to be Corning Glass
Works.




On Wed, Nov 23, 2016 at 8:57 AM, Tom Van Baak  wrote:

> > Chris enjoying the pictures. Most likely I will never run into one of
> these
> > oscillators. But it is nice to know that you have gone "where no man has
> > gone before". Star Trek? Not sure.
> > Regards
> > Paul
> > WB8TSL
>
> Paul,
>
> I have quite a few vintage FTS 1200's here and will be doing a grand
> comparison in a few months. They are known for extremely good ADEV, way
> down in the -13's. I'll put your name on one of them.
>
> /tvb
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Re: [time-nuts] Inside of FT1200-100

[Christopher Hoover]

And of course it is a discontinued part.

Taking suggestions for a replacement.   COG(NP0)?


On Wed, Nov 23, 2016 at 12:25 PM, Christopher Hoover <c...@murgatroid.com>
wrote:

> Part number decoder on page 4 of:
>
> http://www.mouser.com/catalog/supplier/library/pdf/AVXGlassDielectric.pdf
>
> CY = glass
> 06 = case size
> C = operating temp (-55 C to +125 C)
> 240 = 24 pF
> J =  tolerance (+/- 5%)
>
>
>
> On Wed, Nov 23, 2016 at 12:19 PM, Christopher Hoover <c...@murgatroid.com>
> wrote:
>
>> OK, I think this folded-over cap sets the nominal XO frequency:
>>
>> (link in case it doesn't go through: https://goo.gl/photos
>> /XHUCKTnC3NAB5rKD6 )
>>
>> I read the p/n as CY06C240J.   24 pFs?  CGW would seem to be Corning
>> Glass Works.
>>
>>
>>
>>
>> On Wed, Nov 23, 2016 at 8:57 AM, Tom Van Baak <t...@leapsecond.com> wrote:
>>
>>> > Chris enjoying the pictures. Most likely I will never run into one of
>>> these
>>> > oscillators. But it is nice to know that you have gone "where no man
>>> has
>>> > gone before". Star Trek? Not sure.
>>> > Regards
>>> > Paul
>>> > WB8TSL
>>>
>>> Paul,
>>>
>>> I have quite a few vintage FTS 1200's here and will be doing a grand
>>> comparison in a few months. They are known for extremely good ADEV, way
>>> down in the -13's. I'll put your name on one of them.
>>>
>>> /tvb
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>>> ailman/listinfo/time-nuts
>>> and follow the instructions there.
>>>
>>
>>
>
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Re: [time-nuts] New Timestamping / Time Interval Counter: the TICC

[Christopher Hoover]

That TI TDC7200 really is a nice part.

Neat project!   Will buy .  Two thumbs up.


On Wed, Nov 23, 2016 at 7:48 AM, John Ackermann N8UR  wrote:

> Counters with resolution below 1 nanosecond are difficult.  They require
> either outrageous clock speeds, or interpolators that are typically a bunch
> of analog components mixed with black magic and stirred by frequent
> calibration.  The very best single-shot resolution that's been commercially
> available is 22 picoseconds in the HP 5370A/B, with jitter somewhat more
> than that.  My 5370B has an one-second noise ADEV of about 4x10e-11.
>
> With the help of some very talented friends, I've been working on a new
> counter called the "TICC" with <60ps resolution and similar jitter, based
> on the Texas Instruments TDC7200 time-to-data-converter chip.  The
> one-second noise ADEV is about 7x10e-11, not much worse than the 5370, but
> here's the trick:  the TICC is an Arduino shield (mounting on a Mega 2560
> controller) that weighs only a couple of ounces, requires *no* calibration,
> and is powered from a USB cable!
>
> The TICC is implemented as a two-channel timestamping counter.  That means
> it can measure one or two low-frequency (e.g., pulse-per-second) inputs
> against an external 10 MHz reference, or it can do a traditional time
> interval measurement of one input against the other.  It can also measure
> period, ratio, or any other function of two-channel  timestamp data.  (And
> by the way -- multiple TICCs can be connected to yield 4, 6, 8, or more
> synchronized channels, though we haven't tested this capability yet.)
>
> I've attached a picture of the TICC prototype as well as an ADEV plot of a
> 17+ day run of multiple measurements taken by two TICCs, and also showing
> the TICC noise floor.  The good news behind that plot is that there are
> more than 6 million data points behind these results, and there was not a
> single glitch or significant outlier among them.
>
> There's more information available at http://febo.com/pages/TICC
>
> The software is open source (BSD license) and is available at
> https://github.com/TAPR/TICC -- the current version seems be reliable but
> there are still features to add and a *lot* of cleanup to do; it's
> currently ugly and very much a work in process.
>
> As always, I'll be making the TICC available through TAPR.  We're still
> finalizing details, but we expect the price to be less than $200 for a
> turn-key system:  TICC mounted on an Arduino with software loaded and
> tested for basic functionality.  We hope to ship the TICC by February.
>
> I'll post a note in a week or two with final price and ordering
> information.  As a heads up, we will probably offer a small discount for
> pre-orders.  TAPR is a shoestring non-profit group and the up-front cost to
> manufacture this unit will frankly be a challenge for us.  Getting
> pre-orders will help our cash flow significantly, so we ask you to keep
> that in mind.
>
> John
>
>
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Re: [time-nuts] How can I measure GPS Antenna quality?

[Christopher Hoover]

> I'd like to try something like a Voronoi tessellation,  but that gets
rather nasty to implement..

There's a boost library...
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Re: [time-nuts] Inside of FT1200-100

[Christopher Hoover]

A Wiha nutdriver set later and I'm in:

https://goo.gl/photos/SDHtvgFmftQq6vYJA

See the last two pictures.

I will disassemble the board stack and work out some schematics next.

Thanks everyone.
-ch
73 de AI6KG

On Nov 20, 2016 5:19 AM, "J. L. Trantham" <jlt...@att.net> wrote:

Christopher,

Enjoyed the pictures.

You might want to look at these items on theBay.

381408412092

311736541103

I've had the same issue and broke down and bought a set of these small nut
drivers.

Good luck.

Joe

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of
Christopher Hoover
Sent: Saturday, November 19, 2016 11:45 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Inside of FT1200-100

tl;dr: I've made some progress and have the1200  oscillator core out of the
dewar:

https://goo.gl/photos/SDHtvgFmftQq6vYJA



I got some 5 thou brass stock and worked it between the rubber sheet and
the dewar.

That seemed to help but it was insufficient free things up -- I busted off
the unused solder lug trying to pull the core out with it.

Having not a lot to lose, I took a chance that the screws going into the
TO-23 went into threaded holes (rather than being clearance holes with nuts
inside).  This was indeed the case.

With two 6-32 threaded rods into the TO-23 threaded holes and and an
appropriately machined piece of mild steel bar stock suspended across the
case <https://goo.gl/photos/1pfiN2GX3WxYCSbg8>, I was able to easily get
the oscillator core out of the dewar by evenly tightening the the nuts on
the bar.Really easily -- I might have been able to pull it out by just
pulling on the bar stock.  I don't know if the shim stock shenanigans were
even needed.

Despite running out the three sloted screws on the "top" around the
circumference,  I'm not into the inside yet.   I don't have the  right
thin-walled socket to remove the nuts at the opposite end.

I found an epoxy covered hole on the top.   It is/was under the green blob
midway between 1 and 2 o'clock in this picture here <https://goo.gl/photos/
iHbSbqwBiKD7NRfJ6>..  There was something blue and
at this point crumbly underneath it.   Not sure yet what, if anything, is
beyond all of that.  I'm hoping for a trimmer cap.  :-)

-- Christopher.
73 de AI6KG




On Mon, Sep 26, 2016 at 9:24 PM, Chuck Harris <cfhar...@erols.com> wrote:

> Back when I was going to work on mine, I was thinking of prying the
> rubber away from the aluminum oven with something like a feeler gauge,
> but also using some naptha (lighter fluid) to help release any
> adhesive...  I didn't get around to doing it, but that was the way I
> was going to progress.
>
> -Chuck Harris
>
> Ed Palmer wrote:
> >
> >
> > On 2016-09-26 10:00 AM, Christopher Hoover <c...@murgatroid.com> wrote:
> >>> >
> >>> >You might be able to slide something like a feeler guage down
> >>> >between
> the
> >>> >oven and the rubber blanket to break the oscillator free.  The
> >>> >oven
> on mine
> >>> >is a plain metal cylinder.  This way, the rubber sheet should
> >>> >protect
> the
> >>> >Dewar from your feeler guage.  On mine, the mounting bolts for
> >>> >the
> 2N3792
> >>> >transistor both have ground lugs.  I think I see them on yours.
> >>> >You
> could
> >>> >hook something through the ground lugs and use that to pull the
> oscillator
> >>> >out of the rubber sheet and then remove the sheet later.
> >>> >
> >> Thanks Ed,
> >>
> >> I think the rubber sheet on mine is against metal.  I haven't yet
> >> seen
> the
> >> glass dewar.
> >>
> >> The adhesion is huge.
> >>
> >> Do you know if the holes opposite the 2N3792 are threaded?   If they
> are, I
> >> might try running the screws out and using those holes with longer
> screws
> >> as my pull points.I can't pull on the lugs hard enough -- I've
> tried.
> >>
> >> -christopher.
> >> 73 de AI6KG
> >
> > Yes, you have seen the Dewar.  The silvery ring that's outside the
> rubber is the top
> > of the Dewar.  What you have to do is unstick and unfold the rubber
> starting from the
> > open area in the center.  Work your way outward.  The rubber is only
> > 2
> or 3 mm
> > thick.  Once you completely clear the rubber out of the way, you'll
> > see
> the edge of
> > the oven.  The TO-3 transistor is mounted on top of the oven assembly.
> Once you can
> > see the edge, you have to slide something like a long feeler gauge
> > down
> along the
> > edge of the oven to bre

Re: [time-nuts] 53132 replacement fan

[Christopher Hoover]

I was able to cross it easily to a well-known fan manufacturer's part.
If someone doesn't chime in, I'll dig through my notes and get you the
details.

-christopher.
73 de AI6KG

On Sun, Nov 20, 2016 at 11:14 AM, John Ackermann N8UR  wrote:

> Does anyone have a part number for the 53132 fan (or equivalent)?  Mine is
> getting pretty noisy.
>
> Thanks!
> John
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Re: [time-nuts] Inside of FT1200-100

[Christopher Hoover]

tl;dr: I've made some progress and have the1200  oscillator core out of the
dewar:

https://goo.gl/photos/SDHtvgFmftQq6vYJA



I got some 5 thou brass stock and worked it between the rubber sheet and
the dewar.

That seemed to help but it was insufficient free things up -- I busted off
the unused solder lug trying to pull the core out with it.

Having not a lot to lose, I took a chance that the screws going into the
TO-23 went into threaded holes (rather than being clearance holes with nuts
inside).  This was indeed the case.

With two 6-32 threaded rods into the TO-23 threaded holes and and an
appropriately machined piece of mild steel bar stock suspended across the
case <https://goo.gl/photos/1pfiN2GX3WxYCSbg8>, I was able to easily get
the oscillator core out of the dewar by evenly tightening the the nuts on
the bar.Really easily -- I might have been able to pull it out by just
pulling on the bar stock.  I don't know if the shim stock shenanigans were
even needed.

Despite running out the three sloted screws on the "top" around the
circumference,  I'm not into the inside yet.   I don't have the  right
thin-walled socket to remove the nuts at the opposite end.

I found an epoxy covered hole on the top.   It is/was under the green blob
midway between 1 and 2 o'clock in this picture here
<https://goo.gl/photos/iHbSbqwBiKD7NRfJ6>..  There was something blue and
at this point crumbly underneath it.   Not sure yet what, if anything, is
beyond all of that.  I'm hoping for a trimmer cap.  :-)

-- Christopher.
73 de AI6KG




On Mon, Sep 26, 2016 at 9:24 PM, Chuck Harris <cfhar...@erols.com> wrote:

> Back when I was going to work on mine, I was thinking of
> prying the rubber away from the aluminum oven with something
> like a feeler gauge, but also using some naptha (lighter fluid)
> to help release any adhesive...  I didn't get around to doing
> it, but that was the way I was going to progress.
>
> -Chuck Harris
>
> Ed Palmer wrote:
> >
> >
> > On 2016-09-26 10:00 AM, Christopher Hoover <c...@murgatroid.com> wrote:
> >>> >
> >>> >You might be able to slide something like a feeler guage down between
> the
> >>> >oven and the rubber blanket to break the oscillator free.  The oven
> on mine
> >>> >is a plain metal cylinder.  This way, the rubber sheet should protect
> the
> >>> >Dewar from your feeler guage.  On mine, the mounting bolts for the
> 2N3792
> >>> >transistor both have ground lugs.  I think I see them on yours.  You
> could
> >>> >hook something through the ground lugs and use that to pull the
> oscillator
> >>> >out of the rubber sheet and then remove the sheet later.
> >>> >
> >> Thanks Ed,
> >>
> >> I think the rubber sheet on mine is against metal.  I haven't yet seen
> the
> >> glass dewar.
> >>
> >> The adhesion is huge.
> >>
> >> Do you know if the holes opposite the 2N3792 are threaded?   If they
> are, I
> >> might try running the screws out and using those holes with longer
> screws
> >> as my pull points.I can't pull on the lugs hard enough -- I've
> tried.
> >>
> >> -christopher.
> >> 73 de AI6KG
> >
> > Yes, you have seen the Dewar.  The silvery ring that's outside the
> rubber is the top
> > of the Dewar.  What you have to do is unstick and unfold the rubber
> starting from the
> > open area in the center.  Work your way outward.  The rubber is only 2
> or 3 mm
> > thick.  Once you completely clear the rubber out of the way, you'll see
> the edge of
> > the oven.  The TO-3 transistor is mounted on top of the oven assembly.
> Once you can
> > see the edge, you have to slide something like a long feeler gauge down
> along the
> > edge of the oven to break it free from the rubber.  Work your way all
> around the
> > oven.  It's about 85 mm long.  It'll still be stuck on the bottom, but
> you might be
> > able to pull it free.
> >
> > When I took mine apart, I ended up tearing off all the rubber at the top
> and then
> > cutting out that ring of hard foam to get at the Dewar so I could smash
> it more.  I'm
> > guessing you'd rather not do that! :)  But sacrificing the rubber on the
> top might be
> > okay, if you have to.
> >
> > Sorry, but I don't know if the mounting holes for the transistor are
> threaded or
> > not.  In any case, since the oven and Dewar are bonded to the rubber,
> you're pulling
> > on the Dewar when you pull on the oven.  Not a good plan until you break
> the oven
> > free from the rubber.  Those Dewars are built in a rather 

Re: [time-nuts] Questionable content webcomic channels some time nuttery

[Christopher Hoover]

+1

On Nov 7, 2016 4:05 PM, "Gregory Maxwell"  wrote:

> http://questionablecontent.net/view.php?comic=3346
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Re: [time-nuts] I love the smell of tantalum in the morning

[Christopher Hoover]

+1

I only use tweezers for removal.  I use the one-side-then-the-other
technique described elsewhere in this thread for mounting parts.
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[time-nuts] Time nut soon to be in Shenzhen

[Christopher Hoover]

I'm in Shanghai now but will be leaving for Shenzhen in a few days.  Any
one know of any special time nutty stuff to check out in Shenzhen?  I
expect if I can find the right place I might see piles of OCXO's.

Thanks, Christopher and 73 de AI6KG
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Re: [time-nuts] I love the smell of tantalum in the morning

[Christopher Hoover]

Ditto.  I use hot tweezers -- metcal talon handpiece, in my case.   There
are other ways to do it if you don't have them.

On Nov 6, 2016 3:21 AM, "jimlux"  wrote:

> On 11/5/16 12:12 PM, Tom Van Baak wrote:
>
>> See C13 in the attached photo. I need to replace some blown caps on a few
>> boards [1]. In one instance the cap got so hot it melted itself off the
>> board. Quiet convenient, actually -- it acts like its own fuse -- but I
>> don't think the 5071 designers had that clever feature in mind.
>>
>> Having not done SMT before, how should I do it with minimal risk to the
>> very precious PCB. Or, what equipment should I use this as a good excuse to
>> buy?
>>
>>
> Suitable hot tweezers would do this just fine, for both the removal and
> the replacement.
>
> this kind of thing
> http://www.weller-toolsus.com/weller-t0051317199-wta-50-twee
> zers-smd-desoldering.html
> https://www.amazon.com/WMRT-Desoldering-Tweezers-Soldering-
> Stations/dp/B000UMMUII
>
> It's what I've used at work, with a wx2021
> Here's the complete set:
> http://www.weller-toolsus.com/soldering/systems/weller-wx202
> 1-solder-stat-wxmpms-wxmtms-wdh51-wdh60-120v.html
>
> The tips heat basically instantly. It makes it easy to remove/replace even
> tiny stuff, although 0402 is just too small for me.
>
> You need a good magnifier or stereo microscope, and some orange sticks to
> hold things in place while you solder, etc.
>
>
> However, I've been given to understand that there is another superior
> brand (on this list.. )
>
>
>
> Thanks,
>> /tvb
>>
>> [0] http://www.imdb.com/title/tt0078788/quotes
>> [1] http://leapsecond.com/museum/hp5071a/A1-mother.htm
>>
>>
>>
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>>
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Re: [time-nuts] Opening an Isotemp OCXO

[Christopher Hoover]

I got one open without too much much trouble with a propane torch.  Work
fast, use gravity and have something pointy to pry with as you go.

-ch
73 de ai6kg

On Oct 18, 2016 6:14 AM, "Peter Reilley"  wrote:

> I bought an Isotemp OCXO82-59 with a frequency of 10 MHz for a $3 at the
> MIT flea market.
> As expected it was dead.   It heats up as expected but looking at the
> output with a scope there
> is nothing.   However looking at the output with a spectrum analyzer I can
> see a faint 10 MHz
> signal.   It seems that the oscillator is running but the output circuitry
> is dead.   Reasonable
> assumption?
>
> Anyway, has anyone had any luck unsoldering the tin case without
> destroying it?
>
> Pete.
>
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[time-nuts] Roughtime

[Christopher Hoover]

I just learned about this from a public post:

https://roughtime.googlesource.com/roughtime/

Not precise enough for us nuts, but intended to be secure.

(I wonder how it handles leap seconds?   Too soon?  :-)   Actually, it
smears.)

-christopher.
de AI6KG
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Re: [time-nuts] Inside of FT1200-100

[Christopher Hoover]

On Wed, Sep 21, 2016 at 10:05 PM, Ed Palmer  wrote:

>
> You might be able to slide something like a feeler guage down between the
> oven and the rubber blanket to break the oscillator free.  The oven on mine
> is a plain metal cylinder.  This way, the rubber sheet should protect the
> Dewar from your feeler guage.  On mine, the mounting bolts for the 2N3792
> transistor both have ground lugs.  I think I see them on yours.  You could
> hook something through the ground lugs and use that to pull the oscillator
> out of the rubber sheet and then remove the sheet later.
>

Thanks Ed,

I think the rubber sheet on mine is against metal.  I haven't yet seen the
glass dewar.

The adhesion is huge.

Do you know if the holes opposite the 2N3792 are threaded?   If they are, I
might try running the screws out and using those holes with longer screws
as my pull points.I can't pull on the lugs hard enough -- I've tried.

-christopher.
73 de AI6KG
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Re: [time-nuts] Inside of FT1200-100

[Christopher Hoover]

I'm in.

https://goo.gl/photos/SDHtvgFmftQq6vYJA

But the EFC wire goes deeper, so I'll keep at it.   It is fighting me the
whole way.


-- Christopher
73 de AI6KG


On Tue, Sep 20, 2016 at 7:54 AM, Chuck Harris <cfhar...@erols.com> wrote:

> That is the board that contains the heater
> controller, and the output buffer.
>
> You need to get into the tiny vacuum thermos
> bottle where all of the wires go.
>
> -Chuck Harris
>
> Christopher Hoover wrote:
> > Top of the board stack
> >
> > https://goo.gl/photos/cUBtdTYHHWX4ZRbx8
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[time-nuts] Inside of FT1200-100

[Christopher Hoover]

Top of the board stack

https://goo.gl/photos/cUBtdTYHHWX4ZRbx8
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Re: [time-nuts] time-nuts Digest, Vol 146, Issue 13

[Christopher Hoover]

>
>
> Message: 2
> Date: Mon, 5 Sep 2016 19:48:14 -0700
> From: "Richard (Rick) Karlquist" 
> To: Discussion of precise time and frequency measurement
> 
> Subject: [time-nuts] Hobbyist grade or homebrew temperature testing
> chamber?
> Message-ID: <4fb2f3cd-7509-4873-b21f-300161d0b...@karlquist.com>
> Content-Type: text/plain; charset=utf-8; format=flowed
>
> As we all know, step #1 in making a clock is NOT
> to build a thermometer :-)
>
> I thought I would check the brain trust here to see
> if anyone has seen a hobbyist grade temperature
> testing chamber or kit or homebrew design.  I
> have some crystals, oscillators, and other
> electronics I would like to characterize over
> temperature.  I know this reflector has discussed
> homebrew stabilization ovens; however, they
> have tended to have very long time constants
> (which makes sense for that application).  I
> need to be able to change temperature in a
> reasonable amount of time, and I don't need
> extreme stability.  Looking for any ideas,
> maybe in the "maker" spirit.  I think the
> size I need would be perhaps 1/2 the size
> of a shoebox.
>
> BTW, in case someone has a chamber to sell,
> let me know...
>
> Rick Karlquist N6RK
>
>
>
If you need a heater strip,  I am a satisfied and repeat customer of Minco.
  They make polyimide resistive heating elements that can put a lot of Q
into something.

http://www.minco.com/Products/Heat

design guide:

http://www.minco.com/components/~/media/WWW/Resource%20Library/Heaters/Heater%20Design%20Guide.ashx?la=en

-- christopher
73 de AI6KG
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Re: [time-nuts] Adjusting nominal frequency of FTS 1200-100 OCXO?

[Christopher Hoover]

Hi Adrian,

Thank you for your reply.

Is this board deep inside the OCXO?

I haven't ventured past the  output amplifier board stack at the "front."
The styrofoam insulation seems pretty fragile from age and heat.

-christopher
73 de AI6KG


On Mon, Sep 19, 2016 at 12:28 PM, Adrian <rfn...@arcor.de> wrote:

> Christopher,
>
> my 4060 has been locking exactly 0.5 Hz off of the correct frequency.
> The 1000B has had a contact problem on the edge connector.
> Over the years, an insulating black layer had built up between the
> solder and the gold plating of the contacts.
> I had to re-solder each of them carefully twice to get it working reliably.
>
> Regards,
> Adrian
>
> Christopher Hoover schrieb:
> > I've been debugging a FTS 4050 with the 5000M module.
> >
> > It looks like the problem is the FTS 1200-100 OCXO.   It seems to have
> aged
> > to the point that it is very low in frequency.   (Chuck Harris reported a
> > similar situation a long time ago.)
> >
> > I have it out of the 5000M and determined that I need to give it +8.8V on
> > the control to get it within 50uHz of 5 MHz.
> >
> > The power draw after a short warm up is < 2.5W (on this hot day); it
> looks
> > like the oven is behaving.
> >
> > Has anyone figured out how  to adjust the nominal frequency of an FTS
> 1200
> > -100 to recover the EFC range?
> >
> > Also, anyone have a schematic for any model of the FTS 1200?
> >
> > Thanks,
> > -christopher
> > 73 de AI6KG
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> >
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>
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Re: [time-nuts] Adjusting nominal frequency of FTS 1200-100 OCXO?

[Christopher Hoover]

Thanks, Corby.   That was my guess.

Is this cap  buried in the styrofoam block?   (Cue "we need to go deeper"
meme.)

-christopher
73 de AI6KG

On Mon, Sep 19, 2016 at 10:18 AM,  wrote:

> Christopher,
>
> The only way is to open the oscillator up and reselect the capacitor they
> used to set it on frequency.
>
> I've done it once or twice long ago, not easy to do!
>
> I have a 1200 with the same problem however it does tune to 1Hz low so I
> use it as the offset oscillator for my DMTD unit!
>
> Cheers,
>
> Corby
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[time-nuts] Adjusting nominal frequency of FTS 1200-100 OCXO?

[Christopher Hoover]

I've been debugging a FTS 4050 with the 5000M module.

It looks like the problem is the FTS 1200-100 OCXO.   It seems to have aged
to the point that it is very low in frequency.   (Chuck Harris reported a
similar situation a long time ago.)

I have it out of the 5000M and determined that I need to give it +8.8V on
the control to get it within 50uHz of 5 MHz.

The power draw after a short warm up is < 2.5W (on this hot day); it looks
like the oven is behaving.

Has anyone figured out how  to adjust the nominal frequency of an FTS 1200
-100 to recover the EFC range?

Also, anyone have a schematic for any model of the FTS 1200?

Thanks,
-christopher
73 de AI6KG
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[time-nuts] 5061B Service Manual, Page 8-57 (BEAM I, if LOW)

[Christopher Hoover]

My 5061B (with FTS tube) has a low beam current.  Maybe 7 on the meter when
adjusted onto the primary peak.

I bought the Ops and Service manual, but my copy is missing page 8-57 (and
8-56 if that exists).

I'll send a complaint/request to Manuals Plus, but in the meantime can
anyone share a scan of this (fold out) page or at least outline the
procedure?   I'd like to get on with the diagnostics for low beam current.

Thanks,
-christopher.
AI6KG
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Re: [time-nuts] time-nuts Digest, Vol 72, Issue 24

[Christopher Hoover]

 On 7/6/2010 11:13 PM, J.L. wrote:

I could not find any cross reference for either of these NPN transistors but
the 2NA seemed to do just fine.

Thanks for everyone's help.

Joe

1854-0003 (subsequently replaced by 1854-0637) crosses to Moto/On Semi 
SS2199.

1854-0023 cross to 2N2484
1854-0637 crosses to 2N2219A

-ch




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Re: [time-nuts] time-nuts Digest, Vol 72, Issue 38

[Christopher Hoover]

 On 7/9/2010 7:58 PM, Bob Camp  wrote:
For around $4 or so you can get a CPLD and socket that will replace 
all of the logic chips. They will run on +5 and go to 100 MHz. My 
guess is that they would be a bit more repeatable. The downside is 
it's another part to program.


Yep.I ordered a couple boards, but a CPLD on an an all SMT board is 
the direction I am headed.  SMT except maybe for the timing caps ... I 
haven't looked those up yet.


-ch


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Re: [time-nuts] time-nuts Digest, Vol 70, Issue 31

[Christopher Hoover]

On 5/12/2010 10:41 AM, Jim Lux wrote:

It never occurred to me that they might couple, although almost every
other mechanical clock does.

What would the mechanism be?
   


Perhaps if all of them run off the same reservoir 


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Re: [time-nuts] Simple PLL chips, gone ?

[Christopher Hoover]

On 5/4/2010 5:00 AM,  Luis Cupido wrote:

that is something that is easy to source (known to be in production etc)
   


easy to source and known to be in production are very much a mixed 
bag lately.  after the economic slow down, many plants in china and 
other locales let large numbers of workers go.  if you can find a 
stocking supplier with parts in hand, you are good to go.  but beyond 
that you are likely to find trouble.   i have been told that getting 
factories to ramp up production has been difficult.  parts in demand by 
big buyers naturally get preference, and the envelope of parts used by 
consumer goods is but a fraction of all parts offered.


-ch


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Re: [time-nuts] endace time disribution server tds-2

[Christopher Hoover]

On 4/27/2010 5:00 AM, Anthony Blake tony...@gmail.com wrote:

I was disturbed by their implementation of RS422*without*  a ground
return path.. Am I missing something, or is that really dodgey for
distributing PPS?
   


Yes, it is dodgey.   You can make it work without a ground, but it is 
not to spec and it is not robust.


-ch

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Re: [time-nuts] *nix (was Re: Simulating Oscillator Noise:, DifficultiesSimulatingFlicker FM Noise)

[Christopher Hoover]

On 4/25/2010 9:34 PM, time-nuts-requ...@febo.com wrote:

You didn't get me right... UNIX (and offspring Linux) is not dying, but
Xenix, SunOS, Ultrix, OSF/1, HP-UX, IRIX etc. is dying or dead.


HP-UX is still alive and kicking (on Itanium now, not PA-RISC).

-ch


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Re: [time-nuts] 5370A vs 5370B

[Christopher Hoover]

On 3/9/2010 10:09 PM, John Allen j...@pcsupportsolutions.com

wrote:


Hi Mark - do you have a source or part number for the fan?  I seem to remember
that the manuals says 35 or 37 cfm.
   


Without a pressure drop, cfm is is not sufficient to find an adequate fan.

I can put a 5370A/B on a flow bench, but it won't happen soon.

-ch


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Re: [time-nuts] Vremya-ch Hydrogen Masers

[Christopher Hoover]

On 3/1/2010 9:32 PM, time-nuts-requ...@febo.com wrote:

Anyone here have any experience with these masers?

In particular the VCH-1005A?

I have been tasked to look after a number of these units and am currently
going through the manuals (which are in English but written by a Russian, so
they can be challenging:-)
   

Jim,

If they are too much trouble, I will take them off your hands.   My 
Russian is rusty, but I'll manage.


-ch


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[time-nuts] 5071A question

[Christopher Hoover]

We time nuts, and time labs worldwide too, recognize the 5071A as an 
amazingly accurate and precise instrument as well as an extraordinary 
industrial product with these same qualities repeated many times over 
and over.


Most of us know the product was transferred from HP/Agilent to Symnetricom.

My question is as follows.  Is the 5071A (or at least its tube?) still 
in production at Symnetricom to HP/Agilent specifications and quality?


If not, we've really lost something.

-ch


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Re: [time-nuts] CPLDs for clock dividers

[Christopher Hoover]

Paul Swed wrote:

Well not having a lot of luck with the xilinx wise application.
Its a 6.5 GB tar and after a good 5 hr plus download the tar doesn't open
with zipgenious
But 6.5 GB to work a cpld. Seems crazy to me.
   


The web installer will let you do a partial install.

Bear in mind you are getting heck of lot of pretty powerful software for 
the low, low cost of a download.  (This applies to both Xilinx and Altera.)


The suites are not perfect, but you can do fairly complex designs with 
their free software.


An EDA architect (at Cadence) in a past life,
-ch


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[time-nuts] z3816a running on 12V

[Christopher Hoover]

I hadn't seen this mentioned anywhere else, so I thought I point out 
that the Z3816A, at least the one I have that is spec'ed to run on 
20-72V, will run on 12V, if you change the settings of DIP switch S1 on 
the power board.


Normally S1 is set with switches 34 on (24A on the silkscreen) and 
all other off, but if you set switches 12 on (12 on the silkscreen) 
and turn the rest off, it runs fine at 12V.I see about 960 mA @ 12V 
@ 21C after warm up.


There are also settings for 24B, 48A and 48B.   I have not 
investigated the difference between the A  B settings.  Polarity or 
grounding, perhaps.


-ch


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Re: [time-nuts] Digital Clock kit - no Integrated circuits!

[Christopher Hoover]

On 1/8/2010 6:27 PM, time-nuts-requ...@febo.com wrote:

You must see it to believe it!
   


I won't buy one until it comes in surface mount.I *hate* flipping 
PCBs over and clipping leads.


;-)

-ch


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Re: [time-nuts] LH and virtualization (was: time-nuts Digest, Vol 66, Issue 10)

[Christopher Hoover]

On 1/4/2010 2:47 AM, Steve Rooke wrote:

Are you thinking about running it inside a Windows VM on top of another OS?
   


Yes.

I have one non-virtualized Windows install.  But it is on my laptop and 
as my laptop never stays in one place, it is not a good host for longer 
running processes, esp. those that talk to devices attached to serial ports.


All my other boxes run Linux.  I use VirtualBox OSE to run Windows.

-ch


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Re: [time-nuts] time-nuts Digest, Vol 66, Issue 6

[Christopher Hoover]

On 1/3/2010 5:53 PM, time-nuts-requ...@febo.com wrote:

It's not an issue, except possibly vis-a-vis battery life in a laptop.
   


I haven't looked at the source code, but there are other concerns with 
the while (true) { checkStuff(); Sleep(0); } approach.


According to the TFM, Sleep(0) is effectively a NOP when there are no 
other processes at that priorty (If there are no other threads of equal 
priority ready to run, the function returns immediately, and the thread 
continues execution.).


It also follow from the TFM that it will keep lower priority processes 
from running at all.


For me, I'm most worried about behavior under virtualization -- this is 
unlikely to play nice under a VM  unless you choose a non-work 
conserving scheduler (which most people don't choose).


I would add that laptops are not the only machines these day that do 
effective power management.   This will likely keep your cores out of 
any P-states, and the higher power dissipation will keep fans running 
(higher).


As I mentioned off list, a better approach, if it can be made to work 
with the current code structure, is select(2) or poll(2) (or one of the 
newer variants) on UN*X..   The equivalent, TTBOMK, for Win32 is 
WaitForMultipleObjects.All of these leave the process unscheduled 
until there I/O is available or a timeout occurs.


-ch







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[time-nuts] [OT] short run cable assembly vendor?

[Christopher Hoover]

Sorry for the off-topic post, but ...

I'm looking for a vendor who can make a couple of simple power cable 
assemblies for me. 

The first is from a IEC C14 power entry module to an open frame supply 
board-in (Molex 26-48-1035 style) and ground pigtail.


The second is from the open frame supply to our board (whatever is on 
the output side of the supply to whatever is convenient.cheap).


Quantity is 200-300.

Any recommendations?

Thanks,
-ch


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Re: [time-nuts] NMEA time

[Christopher Hoover]

Hal Murray wrote:

Yes, mostly.

PCs have two nasty disadvantages in terms of time keeping.

One is that the CPU clock is typically using spread spectrum to make the EMI 
shielding (a lot) easier.


The other is that the temperature at the crystal depends (a lot) on what the 
CPU is doing.
  
These are both problems, but the biggest issue in reducing jitter often 
is minimizing SMM[1].  Some SMI's can suck up 50 us at a go though most 
are less.  On some platforms you may see SMI's executing at a rate of 
more than 1 Hz.


-ch

[1] http://en.wikipedia.org/wiki/System_Management_Mode


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Re: [time-nuts] The Demise of LORAN (was Re: Reference oscillator accuracy)

[Christopher Hoover]

David I. Emery wrote:

I have emailed my brother in law who is a rear admiral (I think
now called a vice admiral) and currently CFO of the USCG (and as a note
re your alma mater a MIT Sloan grad) and rather loudly said so myself.  
He most likely was part of the group that made the decision... I intend

to ask him why they did it when I next see him.


David,

I see three possibilities: a) modernization (E-LORAN), b) maintain existing 
service and capabilities, c) shut it down.

It would be helpful to know if USCG supports the plan to shut the system down.  


If USCG does not, those of us who are US citizens can lobby Congress to restore 
funding for the service.   There's an educational piece here to do.


-ch



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[time-nuts] z3804a

[Christopher Hoover]

here's one i haven't seen before.  it's on on eb*y -- 280416557414

there's a 10811a, what i'm guessing is some sort of disciplining circuit 
and 12 output channels  anyone know if you feed it 1PPS or 10MHz?   i'm 
guess the latter, presumably from a z3801a.  


sadly too pricey for my taste.

-ch



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Re: [time-nuts] Datum 2100L issues

[Christopher Hoover]

Mark Kahrs wrote:

I'm finally trying to get this epay 2100L time server to go.  First
step was to talk to it, change the host number and then see what I
had...

It appears to me (or it, depending on who you ask), that two
satellites are in view, to wit:

26 ? sig
09 0.000
04 17.604
10 0.000
15 0.000
01 0.000
07 0.000
28 0.000
02 9.802
27 ? sat
Auto 2-D Sats: 4 2

Above 6.0 is considered good.   But, the status command reveals it
is freewheeling --- clearly, since it is neither tracking or
locking.

If I try and use the position command, I get this:

28 ? pos
GPS Engine Busy:2

I can query the GPS software edition:

14 ? gpsversion
Nav 8.8 4/1/0 Sig 10.16 4/1/0
  
You can give a position, but I don't believe it will lock it in -- it is 
a hint.  Here's how mine behaves:


8 ? tim

9 ? sig

Invalid Command

10 ? gps

11 ? sig

12 6.802

02 -1.000

29 1.600

30 5.198

15 0.000

05 1.8

10 4.401

21 5.401

12 ? sat

Auto 3-D Sats: 12 30 10 21 


13 ? pos

lat: 37.2678299 lon: -121.9767228 alt: 62.6665573

14 ? gpsversion

Nav 8.8 4/1/0 Sig 10.16 4/1/0

15 ? vers
Boot Code - Tymserve_2100
 Rev 1.1   12/20/1996 13:07:21
Main Code - TymServe_2100
 Rev 4.1   12/01/2005 14:45:23
16 ? 



What version is your software?

-ch




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Re: [time-nuts] upgrading agilent 53132 counter

[Christopher Hoover]

On 1 October AL1 wrote:
i would upgrade my 53132 with an OCXO 10811, i have the module, but i was told i 
have to change the power supply too.

It's yet the original HP 0950-2496 from Delta,  model :  DPS-43DL-2 (47 Watts).
  


That's the same supply in my 53132A  and at least one of my 53131A's

I don't think you need to change the supply to add the HS or US timebase.

My 53132A mentioned above  has a factory 10811A (HS).

I have also upgraded the 53113A mentioned above with a 10811A (HS).

While the supplies are the same in both, there is a difference between 
the two.


On the 53132A, the heater voltage comes through the ribbon cable.   
There's an extra set of conductors from the power supply to the main 
board as compared to the 53131A.   On the A6 (external oscillator 
board), there's a jumper on J2 that connects the 10811 heater supply to 
nodes from the ribbon cable.


On my 53131A, those extra conductors on the power supply are terminated 
in a 3-pin connector that was left loose inside the box.   When I 
upgraded it to a 10811 A6, I  removed the J2 jumper and plugged this 
power supply connector into J2.   This was according to the Agilent 
service notes.


Other than that, save firmware, I don't believe there are any other issues.

Re: firmware issues, see the Agilent site for details.  If you have 
early firmware, you may have problems.


-ch



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[time-nuts] HP 00105-6100 figures

[Christopher Hoover]

Silly me.  I remembered that I had a late edition 105A/B manual.   It 
took me some time to find it, but look what's in the change notes:


http://www.murgatroid.com/t_and_m/hp-00105-6100-figs.pdf

I think you'll find the schematic readable; the photos, otoh, are 
marginal --  they were not great to begin with.


I'm sharing these because several people on and off list expressed interest.

cheers,
-ch


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[time-nuts] 05061-6174 00105-6044

[Christopher Hoover]

Anyone have schematics for the 05061-6174  00105-6044 boards?  These 
are used to replace the pre-10544 oscillator (the one with A/C warm up) 
with a 10811 in a 105A/B, also presumably in a 5061A given the p/n.



Thanks,
-ch


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Re: [time-nuts] 5071A sensitivity to orientation (was Re: OCXO sensitive to gravity)

[christopher hoover]

Rick Karlquist wrote:

  Len Cutler put in a fix to mitigate against this in the 5071A CBT.

How so?   Is there a 3-axis accelerometer in the 5071A?

-ch


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Re: [time-nuts] HP 106B quartz frequency standard...the story so, far

[christopher hoover]

  The 2N1701 is a general purpose transistor rated at 60V, 2.5A.

I've mentioned this before, but it bears repeating.

If you are having trouble with an old school linear power supply, in 
many cases you can replace the TO-220 PNP pass transistor *and* the 
reguatlor circuit (based on a 723 or whatever) with a modern integrated 
regulator in TO-220 such as an LT1581.  Strip the regular board of 
everything except for the the input and output caps (if they are still 
good) and wire up a pair of resistors to set the voltage.   Add a couple 
of jumpers to complete the circuit.   And then you are good to go.


-ch



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Re: [time-nuts] [OT] Help needed with HP 16700A

[christopher hoover]

Peter Loron pet...@standingwave.org wrote:
I have a HP 16700A logic analyzer that I'm trying to troubleshoot. I  
can get access to the console via the serial port, and I can see that
it boots up normally, except that it fails to start the X server, and  
drops to a login prompt for which I have no credentials.


I inherited one of these at HP Labs, but I don't use it much any more.

Yours looks pretty healthy, except for the display issue.   (You are watching 
it boot up into HP-UX of course.)

This is just a guess, but I'd try it with several different monitors.  It may 
be that the server doesn't like the VESA DDI/DDC information it is seeing.

You might also try using an XDMCP login.   I vaguely recall that is supposed to 
work.  But I'm not sure you can get this to work without being able to set it 
up on the console.

(BTW, I was able to load a more recent software image than what was originally 
on my 16700A when I inherited it.  I found it on the Agilent site, naturally.   
That was five or so years ago.  You might want to check there.)

-ch




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[time-nuts] TubeSat Personal Satellite Kit

[christopher hoover]

Anyone want to chip in and launch some clocks?  :-)

http://spacefellowship.com/2009/08/01/interorbital-syatems-tubesat-personal-satellite-kit/

Excerpt below.

-ch


 Interorbital Systems -- TubeSat Personal Satellite Kit
 
http://spacefellowship.com/2009/08/01/interorbital-syatems-tubesat-personal-satellite-kit/

By
Rob Goldsmith

*Published:* 01 August 2009 10:15 AM CEST  Source 
http://interorbital.com/TubeSat_1.htm


*Planet Earth has entered the age of the Personal Satellite with the 
introduction of Interorbital's TubeSat Personal Satellite (PS) Kit. The 
new IOS TubeSat PS Kit is the low-cost alternative to the CubeSat. It 
has three-quarters of the mass (0.75-kg) and volume of a CubeSat, but 
still offers plenty of room for most experiments or functions. *


And, best of all, the price of the TubeSat kit actually includes the 
price of a launch into Low-Earth-Orbit on an IOS NEPTUNE 30 launch 
vehicle. Since the TubeSats are placed into self-decaying orbits 310 
kilometers (192 miles) above the Earth's surface, they do not contribute 
to any long-term build-up of orbital debris. After a few weeks of 
operation, they will safely re-enter the atmosphere and burn-up. 
TubeSats are designed to be orbit-friendly.  Launches are expected to 
begin in the fourth quarter of 2010.


TubeSat Personal Satellite Kit 
http://spacefellowship.com/wp-content/uploads/2009/08/Tubesat-solar-cells-antenna-earth-background-assembly-Heading-1.jpg 



TubeSat Personal Satellite Kit

Total Price of the TubeSat Kit including a Launch to Orbit is $8,000!

[]

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Re: [time-nuts] 5087B (was What's the cleanest way to produce 1 and 5 MHz from 10 MHz?)

[christopher hoover]

From: Lux, James P (337C) james.p@jpl.nasa.gov wrote:



 There's slots for three input modules (A,B,C), and 10 output modules 
(1-10), and they're all optional and easily reconfigurable.
Just to be clear, the modules themselves aren't reconfigurable, but the 
mainframe is.  

That said, the 1 MHz, 5 MHz and 10 MHz output amps share the same 
circuit topology and board layout (although IIRC the actual boards are 
marked distinctly.).   It is easy to convert a 5MHz output amp to 10MHz 
and vice versa by changing a couple off-the-shelf Cs.   The 1MHz output 
amp has a different transformer in addition to several other parts.  The 
transformers are HP specials with unspecified characteristics.


-ch


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[time-nuts] e*ay: AUSTRON MODEL 1210D-O1 CRYSTAL CLOCK OSCILLATOR

[christopher hoover]

item # 220403183258.

listing says 3 available.

nice, but a little too spendy for me.

-ch


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Re: [time-nuts] surplus carrier phase measurement-capable receivers (was Thunderbolt firmware differences)

[christopher hoover]

I wanted to have Heather make a RINEX file that could be submiited to OPUS-GIS to get a more precise antenna location.   The Tbolt does not support carrier phase measurements.  It does output doppler values.  


The code phase (pseudorange) values that it outputs look to be VERY difficult 
to translate into normal pseudoranges.  You need to calculate the satellite 
positions from the almanac, etc to be able to use them.

OPUS-GIS is still in alpha testing mode.  I don't know what observable you need 
to have it post process the data.
  
What typically-available surplus receivers do carrier phase 
measurements[1]?   I'm close to putting up a choke ring antenna I scored 
off of the surplus market on the roof -- I don't think the wife is going 
to let me build a proper monument in the yard.  :-) Hence, I, too, 
am interested in getting a precise antenna fix.   I 'spose I could hire 
a surveyor, but that's cheating. 


-ch

[1]. I did enough work w/surplus SuperStar receivers that I convinced 
myself I could flash the carrier phase-capable software onto the board, 
but that's stealing.  I am interested in receivers where I can  get 
legitimate access to carrier phase measurements.



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[time-nuts] Z3817A manual or details?

[christopher hoover]

Anyone else playing with one of these Z3817A boxes that are/were 
available on that marketplace which shall not be named?


The Z3817A appears to be essential a discipling box for an E1938.   I'm 
still not sure yet what the disciplining input is.


I'd love a manual, but I haven't found one yet.   So I've been doing 
some reverse engineering.


On the TIB (P1) DB-25 connector, I'm fairly confident about these:

V+  pins 1 and 21
V-  pins 8 and 25
10MHz #1pins 2/15 xfmr coupled, ~4.6V into 1M
10MHz #2pins 23/16 xfmr coupled, ~4.6V into 1M
1PPSpin 14

Supply voltage is dictated by Lucent DC-DC converter.  Input is 18-36V, 
1.9A.


Still chasing down the other pins.  Currently I am working on a possible 
disciplining input:


input of some kind to U6/3 via 100 ohmspin 18, prob. diff with 4
input of some kind to U6/2 via 100 ohmspin 4, prob. diff with 18

The MMI (J1) DB-9 connector is RS-232, 9600baud, 8n1 and runs a a 
familiar SCPI interface as you can see:


scpi *IDN?
HEWLETT-PACKARD,Z3817A,3832A03064,3752-A
scpi :SYSTEM:STATUS?
SYNCHRONIZATION ... [ Outputs 
Invalid ]
SmartClock Mode ___   Reference Outputs 
___
  Locked TFOM 9 
FFOM 3

  Recovery   1PPS TI  --
  Holdover   HOLD THR 1.000 us
 Power-up: TIMEREF1 invalid Holdover Uncertainty 


 Predict  --
   
ACQUISITION ... [ TIMEREF1 (GPS) 1PPS 
Invalid ]
Tracking: 0    Not Tracking: 0    Time 

 TIME --:--:-- [?] -- 
--- 

 GPS 1PPS Invalid: not tracking
 ANT DLY  --
 Position 


 MODE Hold
 
 LAT  
--   
 LON  
--   
ELEV MASK --  HGT  
--   
HEALTH MONITOR . 
[ OK ]
Self Test: OK  | Int Pwr: OK   Oven Pwr: OK   OCXO: OK   EFC: OK   GPS 
Rcv: OK  

scpi 


-ch



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[time-nuts] AD9548 - Clock IC Generates Up to 400 MHz from 1 PPS GPS Signal

[christopher hoover]

[fyi -- this may be of general interest, but n.b. that this A.D. 
marketing - ch]



Clock IC Generates Up to 400 MHz from 1 PPS GPS Signal

The AD9548 
http://www.analog.com/en/clock-and-timing/clock-generation-and-distribution/ad9548/products/product.html 
is the first clock chip in the industry to directly generate up to a 400 
MHz output clock, with extremely low phase noise, that is locked to a 
standard one pulse-per-second (PPS) GPS clock signal. This performance 
is a result of combining Analog Devices' proprietary direct digital 
synthesis (DDS) technology with a state-of-the-art digital phase-locked 
loop (DPLL). Other solutions for synchronizing to the GPS 1 PPS source 
typically rely on one or more frequency upconversion steps. Maintaining 
low output noise, while providing over eight orders of magnitude of 
frequency scaling (1 Hz input to over 100 MHz output), is a significant 
challenge. The AD9548 is able to mitigate this effect thanks to a 
digital loop filter capable of bandwidths as low as 1 MHz (10 Hz to 3 Hz).



/
/


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Re: [time-nuts] 5070B once more.... (actually 5370A fans)

[christopher hoover]

Magnus wrote:
Having 1-10 kW per rack is not uncommon these days, so 
forced convection needs to be done


That and more.  A fully loaded 42U rack of HP C-class blades runs 8 kW idle and 
peaks at 24 kW.

This can be air cooled (easily) in a properly designed and commissioned 
run-of-the-mill raised floor data center.

It is unfortunatly common to see racks where one box has an airflow 
left-to-right while ontop of it is one with right-to-left and the rack 
has very narrow space between the side of the boxes and the sides


Hot aisle/cold aisle arrangement is current best practice.  (Colleagues in my 
group at HP Labs were the first to do CFD analysis on data centers and 
established many of today's best practices.)

The key is to avoid mixing of cold and hot air as that destroys exergy.

IT equipment is mostly well-behaved as typically installed.   There is a one notable exception -- rack switches are often mounted from the rear and blow hot air out the front into the cold aisle.   (HP recently announced a switch where the flow can be reversed where need be.)


The other problem, which you have alluded to, is gear intended for a telco 
environment.  Unfortunately that includes most data center core switches.   
These, as you indicate, typically exhaust to the side.

-ch




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Re: [time-nuts] Austron 2100F

[christopher hoover]

Chuck Harris cfhar...@erols.com wrote:

 They can be very hard to fix, because there is some really poorly designed
 logic circuitry, and the signature analysis functions really can't find
 very many problems.

Interesting.  Can you say more?   

I tried to repair mine -- I have a signature analyzer -- but did not ever get 
it to work.  The initial indication was a bad memory chip.  I carefully 
replaced it, but it never came back to life.  Maybe that was a red herring.

-ch




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Re: [time-nuts] time-nuts Digest, Vol 56, Issue 54

[christopher hoover]

All this talk of legal time is interesting, but I am hoping we will soon
return to more important matters, like phase locking CD players and plasma
screen dot clocks to CBTs and the best commercially-available phase-stable
speaker cabling.

:-)

-ch



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Re: [time-nuts] Initial release of Lady Heather for Windows

[christopher hoover]

John Miles wrote:
 Thanks for the confirmation -- I don't believe anyone else has tried it
 on
 Windows 7 before.  Did you have to run it as admin?
 
 Christopher, I imagine there's either a WoW64 compatibility problem or
 (more
 likely) the unit you're using isn't 100% compatible with Trimble's TSIP
 implementation for the Thunderbolt.  It would be interesting to hear if
 you
 can try 64-bit Vista with a real Thunderbolt; 

John,

With a real Thunderbolt, it works perfectly fine on real COM1: under Vista
SP1 x64 without elevation (UAC on).

It just doesn't like the Trimble GPSTM's TSIP.  (BTW, anyone else have one
of these?)

Thanks guys.

Cheers,
-ch



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Re: [time-nuts] Initial release of Lady Heather for Windows (John Miles)

[christopher hoover]

John Miles jmi...@pop.net wrote:
 This is my version 1.0 release:
 
 http://www.ke5fx.com/heather/readme.htm
 
 The app is a decent graphical replacement for tboltmon.exe at this
 point, IMHO.  If you currently run tboltmon on your Thunderbolt,
 give this release a try.

Is it known to run on Vista?   How 'bout Vista x64?

I'm trying on Vista x64 with a GPSTM (related but not actually thunderbolt),
I get:

Serial receive error, code 0x2.

Serial port is fine, connected, no other processes attached, etc.

Can I send you any more debugging info?

I'll have to dig out one of my Thunderbolts to see if the GPSTM itself is
the problem.

-ch





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Re: [time-nuts] Sound cards

[christopher hoover]

John Ackermann wrote:

 One very interesting possibility is the HPSDR (High Performance
 Software Defined Radio) boards called Ozy and Janus.  

 I'm not aware of anyone using this system for TF work, but it has some
interesting possibilities.

I bought mine for tf work, but sadly I have not gotten to it: I just can't
seem to get my 2.5 yo boy interested enough in the subject yet, although he
is very adept at removing all the dust caps from my gear.  :-)

-ch



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Re: [time-nuts] good book on the history of calendars?

[christopher hoover]

Robert Darlington wrote:
 So you want to exclude all of the interesting parts of calendar
 history?   I personally think most of the fun stuff happened 6-10
 thousand years before that period.

I'll take what I can get.  I'm not uninterested in earlier calendars, but,
yes, I am especially interested in modern developments, for some suitable
definition of modern.  :-)

-ch



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Re: [time-nuts] Leap Quirks

[christopher hoover]

Hal Murray wrote: 
 Two of my Linux systems hung.  One was running a 2.6.25 kernel and one
 2.6.26.  A system running 2.6.23 worked fine.  I saw a couple of notes
 on
 comp.protocols.time.ntp about Linux systems locking up.  One said that
 it was
 a kernel bug in ntp.c but I haven't seen any details.

None of mine (many dozens) hung.This is typical:

c...@snaggle:~$ uname -a
Linux snaggle.murgatroid.com 2.6.26-1-amd64 #1 SMP Mon Dec 15 19:40:58 UTC
2008 x86_64 GNU/Linux
c...@snaggle:~$ dmesg | grep leap 
[844362.415072] Clock: inserting leap second 23:59:60 UTC
c...@snaggle:~$


-ch




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Re: [time-nuts] prototyping (was Sub Pico Second Phase logger)

[christopher hoover]

Joseph M Gwinn gw...@raytheon.com wrote:
 
 Actually, for quantity one, I don't bother with PCBs.  I use 1/16 inch
 thick glass-epoxy Vectorboard with a 0.1 hole pitch, and thread bare
 wire through the holes.  

...

 If I were building receivers, I suppose I would be forced to use
 surface-mount comoponents and PCBs.

For one off and experimentation, ugly style on a solid ground plane works
quite well.   I have built a number of receivers in this style.

There are kits available of self-adhesive bits of PCB that you can stick
onto the ground plane to create islands or to mount delicate parts.  You can
get away without these -- e.g. by the judicious use of an xacto knife --
but they certainly are handy.

Of particular relevance to the quoted text, you can get strips of PCB for
50Z, 75Z, etc transmission lines -- we have these in our labstock.  (Sorry,
I forget the brand name.)

-ch



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Re: [time-nuts] Fwd: M12+T ASCII interface - I'm confused?

[christopher hoover]

tvb wrote:
 I hope you end up liking the binary format; I'm not sure how it could
 be improved.

IIRC, there's no length field in the packet; so you have to know the length
of all the messages you might possibly rx, even if you are interested in
just a few of them.

-ch



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Re: [time-nuts] Fine delay generator (Tim Shoppa)

[christopher hoover]

Tim Shoppa wrote:
 mostly they were using custom-wound nonlinear wire-wound pots and 
 motors driving shafts to make the phases :-).

Oh, that is so cool!   And obvious once you think about it.   I love stuff
like that.

Are there pictures?

(It seems like you could do this pretty well with thin film technology
today.)

-ch



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Re: [time-nuts] Do any regulations or laws require time to be within ?x? seconds?

[christopher hoover]

On Mon, Nov 3, 2008 at 12:03 PM, Gretchen Baxter
[EMAIL PROTECTED] wrote:

 There are a lot of regulations that mandate synchronized time.

 

 But do any of these regulations or laws require time to be accurate 

 within 'x' seconds?  Such as, 'time much be synchronized within 5 

 seconds of GPS time.

 

Financial services industries (FSI) operate under very strict rules on the
order that trades execute and on the currency (ha ha!) of price quotations.
See Rule 601 and 610.  (Cf. http://en.wikipedia.org/wiki/RegNMS )

 

I know of at least one company that has asked for better than what a typical
x86 server + ntp will do.

 

- ch

 

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Re: [time-nuts] Help with Datum/Symmetricom TymServe TS2100

[christopher hoover]

 
Skip Withrow [EMAIL PROTECTED] wrote:
 I have recently acquired a Datum TS2100-IRIG NTP time server.  Nice
 unit, and I do have IRIG-B to feed it, however, reading the manual I
 notice that there is a GPS version as well.  Upon taking the top of the
 unit off I notice that there are the connector and standoffs for both
 Oncore
 and Trimble ACE-III sized receivers.  Tried plugging both in, but the
 unit
 does not
 seem to recognize it (always reports GPS receiver busy).

I was able to make this conversion with an ACE-III module (thanks Jason!).
I am a bit fuzzy on the details now and my notebooks are packed away in some
random box, but I do recall that it was important to set the ACE-III to
speak the right protocol -- TSIP, IIRC.  There may have been an issue with
speed as well.  A logic analyzer on the TS's Tx pin was helpful.  I have a
vague memory of sending out a note about my successful conversion, so you
may want to check the archives.

What I am certain of is that Symmetricom is not going to be of any help.
Abandon all hope there.

-ch



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Re: [time-nuts] Odd HP 117A configuration

[christopher hoover]

Brooke Clarke [EMAIL PROTECTED] wrote:
 The same company has another program
 that decodes the Northern California DX beacons
 (as controls the receiver frequency).  Note the 
 beacons transmit in GPS controlled time slots
 with stepping RF power levels.

The whha...at beacons?   Is there a web page
Where I can learn more?

-ch



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Re: [time-nuts] Help with HP 8640B generator (Richard (Rick) Karlquist)

[christopher hoover]

Richard (Rick) Karlquist [EMAIL PROTECTED]L:
 Going back to Agilent's origins at HP, AFAIK, only Hewlett and Packard
 ever had traditional offices with walls to the ceiling and doors.
 Their offices are preserved in the condition they were in when
 H  P left the company.  Employees can visit these offices, which
 are like a museum.

Yep, they are still there, as is the old board room.  

My cubicle at HP Labs is about 25 yards away from them.

The old board room is still use, mostly for customer visits to Labs.

-ch



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Re: [time-nuts] While we're discussing backups...

[christopher hoover]

Robert Vassar said:
 There have certainly been some amusing replies.  My only point was
 that if it you are storing stuff on spinning rust, you can't call
 it a backup if it's still spinning.  Power it off and de-cable it.
 How much further you go after that to protect it depends on your risk
 requirements.  I did like the zip-loc bag idea.

I've been trying to stay out of this, but I have some expertise digital
asset preservation, as it has been a recent research area of mine.

(Someone referred LOCKSS -- that's good work and a nice place to start; one
of its creators is a colleague of mine.)

A couple points are worth making:

Diversity of all kinds is good.  This would include geography, operating
system, media, administrative control, 'players' (i.e. someway to interpret
the bits) et al.

Extra copies are good (and, yes, you can use coding to avoid 100% overhead
for every copy), but you rapidly lose the benefit of the extra copies if you
do not actively repair them quickly (enough) after they fail.   

And here's the rub: a significant fraction of storage failures are latent --
they go undetected until you attempt to retrieve and 'perform' the asset.  

So to make sure your copies are good, you must audit them regularly.   Given
trust between administrative domains, this can be as simple as comparing
cryptographic hashes of the bits.   (There are also schemes that work
without assuming trust.)

I don't have the ref handy at the moment, but we have a model and math that
quantifies the issue around latent errors.
 
But don't audit too often, if the auditing mechanism causes wear.   How
often is often enough is left an exercise for the reader.

These are of course general principles.  You still need to look at your
threat model and the value of your data and make reasonable engineering
choices.

-ch




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Re: [time-nuts] rsync (was Odetics 325 425: File recovery)

[christopher hoover]

John Ackermann N8UR [EMAIL PROTECTED] wrote:
 You can pipe rsync over SSH; 
 I don't recall the exact magic to make rsync plus 
 SSH work under Windows, but I think you could use PuTTY or Teraterm to 
 provide the port forwarding.

No port forwading is necessary nor recommended.

rsync does ssh natively when you specify [EMAIL PROTECTED]:  I.e.:
 
  rsync dir1 [EMAIL PROTECTED]:/dir2

This how rsync is used 98% of the time.  

(If you actually want to speak to an honest-to-goodness rsync server that's
already running, you have to use the rsync:// url syntax.)

-ch




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[time-nuts] Complete Lucent RFTG setup on eBay

[christopher hoover]

There have been lots of messages about how the Lucent RFTG disciplined
oscillator bits work in a system.

 

This, from its appearance, is the entire set up with all necessary cables
and proper connections:

 

1 - Lucent RFTGm-II-Rb 15MHz Frequency Reference with 10MHz output
1 - Lucent RFTGm-II-XO 15MHz GPS Disciplined Frequency Reference
Interconnection cable set and mounting frame

 

eBay item # 300244547378

 

(This is not my auction; I have no relation to the seller.)

 

The (quite detailed) pictures alone are worth a look if you are interested
in this gear.

 

-ch

 

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Re: [time-nuts] HP58504A antenna

[christopher hoover]

Bruce wrote:

 Circuit is exactly that to be expected with a discrete pHEMT or similar
 device.
  It looks to me as if the bias flows through the trace on the BR
  and then through a couple of 001 R's before the bias
  setting 221 R.
 
 
 Nonsense they are 100 ohm resistors text is upside down.

Ah!  

  This MMIC is before the filter, so it is probably been selected
  and biased to avoid IM problems.
 
 
 Its unlikely to be an MMIC as they generally have all the bias parts
 internal to the chip other than an output biasing resistor.
 Also most MMICs do not have the input connected to dc ground.

I stand corrected.

-ch



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Re: [time-nuts] Frequency divider design critique request

[christopher hoover]

David Partridge wrote: 
 CPLD - wassat?  OK, OK I have some idea, but that's about all I know.
 Anyway these are probably BGA stuff which I couldn't hope to hand solder
anyway

Many CPLD's are leaded.  Only the high-pin count CPLD/FPGA's are BGA.
 
 Chris Hoover,

Christopher, per favor.

 You mean you've got something that does all that and more and you've
 kept quiet about it!  Shame on you!  Or is it really only in the early
 stages of gestation?

We don't have a board yet, but the code works fine on the Digilent proto
board and the REFLOCK II board.  The latter is Altera rather than Xilinx,
but the same code works on both, but you have to tweak the pin assignments
naturally.

As I said, I am happy to make the VHDL available.   I ought to put under
revision control somewhere.

-ch



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Re: [time-nuts] Frequency divider design critique request

[christopher hoover]

John Miles wrote:
 I am not a big fan of BNC connectors on the PC board itself, because I
 am not a big fan of attaching PC boards directly to panels in most cases.
 
 There are usually some BNC bulkhead connectors on eBay that terminate
 in SMA/SMB/SMC pigtails, which are great for panel mounting.

I strongly concur.

Using SMA/SMC connectors also makes the board more reusable as part of a
bigger system.  

I like to use vertical SMA/SMC connectors on boards and right-angle
connectors on any coax going to a board.  With this configuration, you can
cram a lot of boards in a box even at 1U height and use the remaining
vertical space for cross-connections.

-ch



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[time-nuts] Re Frequency divider design critique request

[christopher hoover]

Bruce wrote.
 However this adds considerable complexity and would be much easier to
 implement in a CPLD or FPGA.

John and I have a design sketch based on a CoolRunner-2 CPLD that we have
been kicking around as a potential TAPR board.   The CR2 is nice in that the
flip flops can be clocked on both rising and falling edges, so doubling any
input signal is trivial, if you need that.
 
I have VHDL (that I'm happy to share) that implements most of the
functionality that has been discussed.  I use it with some frequency (ha
ha!) on several different dev boards and often on the Refclock II board
(which has SMA connectors, I should note).

John and I have both been preoccupied with Life over the last N months and
haven't gotten back to the project yet.

-ch



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Re: [time-nuts] HP 5087A Input Doubler and 10 MHz Ampifiers

[christopher hoover]

NE8S [EMAIL PROTECTED] wrote:
 I am in need of the following Opt PCB's for the HP 5087A:
...
 Qty. 115087-60012 (10 MHz Amplfiers)

Good luck.  I like to a have some more of these as well.

I have considered doing a run of 60012 boards.  This would be
straightforward except for one thing: I have been unable to find any spec
for the transformers.  That part would have be to characterized.

Note that you can convert 5MHz boards to 10MHz by changing a couple of
discrete component values.

-ch




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