Re: [time-nuts] 53230A input channel fault?

[Adrian Godwin]

I recently got a used 53131A. It had the same problem, even though the
BNC connectors are fixed to the front panel.



On Wed, Nov 19, 2014 at 2:18 PM, Anders Wallin
 wrote:
> A colleague of mine had seen this exact same behavior on another 53230A.
> The problem is a narrow trace right after the CH1 BNC input.
> http://www.anderswallin.net/2014/11/53230a-counter-input-channel-fix/
>
> There might be some chemical corrosion going on, since the other counter
> that experienced this problem had definitely not been subjected to
> overvoltage or other abuse. Or perhaps it's a mechanical issue where the
> BNC-connector over time bends the PCB+trace. The BNCs don't appear
> mechanically anchored to the front-panel, they are just soldered to the PCB
> and stick out through holes in the front panel.
>
> We have one of the 100ps models and probably a third 20ps model also - time
> will tell if these will break in the same way...
>
> Agilent/Keysight - are you listening?!? fix it please :)
>
> Anders
>
>
>> Hi all,
>> >
>> > I have a 53230A that behaves differently on ch1 and ch2.
>> >
>> > With ch2 at DC/1Mohm/postive-slope/1V it triggers ok on my PPS signal and
>> > shows e.g. a pusle-width measurement etc.
>> > The same signal connected to ch1 fails to trigger.
>>
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Re: [time-nuts] Upgrade an HP 5342A microwave frequency counter to have an oven oscillator.

[Adrian Godwin]

Is the upgrade similarly easy on a 53131A ?

I realise that it needs to have an additional controller pcb but I
have one of these counters fitted with option 001. The pcb holding the
oscillator has an edge connector that looks suitable for a 10811A, and
I have one to hand as well as a couple of compatible oscillators.

I think I would need to remove the existing TCXO module - I haven't
investigated too carefully yet but I think it's soldered in, and
obstructs the mounting of the 10811A.

On Sat, Nov 29, 2014 at 5:20 PM, Dr. David Kirkby (Kirkby Microwave
Ltd)  wrote:
> On 27 November 2014 at 22:38, Dr. David Kirkby (Kirkby Microwave Ltd)
>  wrote:
>> The HP 5342A has an optional oven oscillator. I just bought one of
>> those counters, but mine has a TCXO and is about 50 kHz off at 10 GHz.
>> I'm sure I can trim it closer than that, but if possible I'd like to
>> stick an oven oscillator in it. Does anyone know what is involved? I
>> have at least one 10811A oscillator here that I could stick inside,
>> but does it need any more, or just the oscillator?
>>
>> Someone said the oscillator should be an 10544-60011, but a 10811A is
>> backwards compatible.
>>
>> Dave
>
> It was very easy to fit the 10811A oven (HP 10811-60111) and get the
> oven working, although the oven is not powered when the counter is not
> switched on, even if there is power at the AC mains input. I can live
> with that. In fact, I prefer it to be honest.
>
> The procedure was
>
> 1) Remove top and bottom covers, which means the two front feet, plus
> 4 rear feet/protectors need to be removed.
>
> 2) Undo one screw at the top that held a board with a TCXO on it. The
> board plugs into a 15-pin edge connector.
>
> 3) Pull out the board (HP P/N 05341-60047) with the TCXO. The TCXO on
> the board is a marked  DALE, TCXO-22-1, 0960-0394, 10.0MHz, SET 1.0Hz.
> (normally I would put a space between a number and the units, but I've
> written what is actually on the TCXO).
>
> 4) Attempt to insert the 10811A oscillator. This failed, as there were
> some wires around the optional board for GPIB which were restricting
> the space too much. So I had to cut a wire tie, and move the wires out
> the way.
>
> 5) Fitted 10811A at the top.
>
> 6) Invert the counter, and screw in the two screws which secure the
> 10811A to the chassis. For this I needed to temporarily move a ribbon
> cable, as the screw was below it.
>
> 7) Powered it up, and it worked. It shows "OVN" in the right of the
> LED display. Once that went out, it still took a minute or two for the
> readings to become pretty stable, although no doubt it will take
> months to become as good as it will get.
>
> I've not adjusted it yet, as I don't have any accurate frequency
> reference. But whilst the actual frequency indicated on the counter is
> different from what my signal generators are supposed to be producing,
> the last few digits (100, 10 and 1 Hz), are not all jumping around
> when seeing 10 GHz.
>
> The frequency indicated on the counter when connected to two different
> signal generators, which both have ovens of unknown type, are:
>
> 1) HP 83623A 20 GHz sweeper set to 10.0 GHz, fed into high frequency
> input of the frequency counter.
> HP 5342A counter indicates 10,000,000,690 Hz (relative difference = +6.9 
> 10^-8)
>
> 2) HP 8656A set to 100 MHz,
> HP 5342A counter indicates 99,999,987 Hz (relative difference = -1.3 x 10^-7)
>
> With the old TCXO in the frequency counter, the indicated frequency of
> the 10 GHz signal was about 48 kHz off, but it moved around a KHz or
> so. In contrast, now the oven is installed, the reading is a *lot*
> more stable, with it shifted about 15 Hz.
>
> I don't currently know the absolute accurate any of the references in
> the test equipment are, but certainly the readings are a lot more
> stable after fitting the oven.
>
> I will need to get a GPSDO before adjusting any, but if nothing else,
> the short term stability of the oven is clearly superior to the TCXO.
> Long term should be too, but I can't determine that from what I have.
>
> Dave
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Re: [time-nuts] Upgrade an HP 5342A microwave frequency counter to have an oven oscillator.

[Adrian Godwin]

I've seen Gerry's board and might well fit one to another counter.
However, this already has a suitable board - in fact, it appears it is
an oven, not a tcxo. Presumably just not as good an oven.

The point is, it looks ready to receive a 10811A. In fact, consulting
the assembly-level service guide does seem to confirm that it uses an
Isotech oven for medium stability or one of two 10811 variants for
high and ultrahigh stability.

Since the 10811A I have is an older model, neither 10811-60160 or
10811-60260, is it likely I'll get any improvment over the Isotech
1813-0931
?

Photos of the board :

https://www.dropbox.com/s/w4nngyz1qp70skv/P1280343.JPG?dl=0
https://www.dropbox.com/s/ifjcx6xzz90vlja/P1280344.JPG?dl=0


On Sun, Nov 30, 2014 at 4:38 PM, Bob Camp  wrote:
> Hi
>
> If you *need* portability, an internal oscillator is a good thing. If you 
> want to fire something up fast, an OCXO is not a good choice. That's a bit of 
> a problem.
>
> A few real choices:
>
> 1) Get something like the LTE that locks up to GPS and runs right away. When 
> portable, bring along a small GPS antenna.
>
> 2) Run a TCXO in the counter while portable and an external reference on the 
> bench.
>
> 3) Power up the counter with internal OCXO the night before any "portable" 
> measurements.
>
> There really aren't a lot of other options unless you head off into the 
> portable atomic clocks.
>
> Bob
>
>> On Nov 30, 2014, at 11:08 AM, Götz Romahn  wrote:
>>
>> Adrian,
>> if you do not insist on a hp10811A, have a look at Gerrys site
>> http://gerrysweeney.com/update-diy-hpagilent-53131a-010-high-stability-timebase-option-pcbs-available/
>> You can buy an assembled option 10 compatible OCXO modul for less than 100 
>> GBP.
>> I built DIY one with a PCB from Gerry using my Morion MV89 OCXO and it is 
>> working fine. Fully compatible with hp53131 calibration procedure.
>> Götz
>>
>>
>>
>> Am 29.11.2014 22:19, :
>>> Is the upgrade similarly easy on a 53131A ?
>>>
>>> I realise that it needs to have an additional controller pcb but I
>>> have one of these counters fitted with option 001. The pcb holding the
>>> oscillator has an edge connector that looks suitable for a 10811A, and
>>> I have one to hand as well as a couple of compatible oscillators.
>>>
>>> I think I would need to remove the existing TCXO module - I haven't
>>> investigated too carefully yet but I think it's soldered in, and
>>> obstructs the mounting of the 10811A.
>>>
>>> On Sat, Nov 29, 2014 at 5:20 PM, Dr. David Kirkby (Kirkby Microwave
>>> Ltd)  wrote:
 On 27 November 2014 at 22:38, Dr. David Kirkby (Kirkby Microwave Ltd)
  wrote:
> The HP 5342A has an optional oven oscillator. I just bought one of
> those counters, but mine has a TCXO and is about 50 kHz off at 10 GHz.
> I'm sure I can trim it closer than that, but if possible I'd like to
> stick an oven oscillator in it. Does anyone know what is involved? I
> have at least one 10811A oscillator here that I could stick inside,
> but does it need any more, or just the oscillator?
>
> Someone said the oscillator should be an 10544-60011, but a 10811A is
> backwards compatible.
>
> Dave

 It was very easy to fit the 10811A oven (HP 10811-60111) and get the
 oven working, although the oven is not powered when the counter is not
 switched on, even if there is power at the AC mains input. I can live
 with that. In fact, I prefer it to be honest.

 The procedure was

 1) Remove top and bottom covers, which means the two front feet, plus
 4 rear feet/protectors need to be removed.

 2) Undo one screw at the top that held a board with a TCXO on it. The
 board plugs into a 15-pin edge connector.

 3) Pull out the board (HP P/N 05341-60047) with the TCXO. The TCXO on
 the board is a marked  DALE, TCXO-22-1, 0960-0394, 10.0MHz, SET 1.0Hz.
 (normally I would put a space between a number and the units, but I've
 written what is actually on the TCXO).

 4) Attempt to insert the 10811A oscillator. This failed, as there were
 some wires around the optional board for GPIB which were restricting
 the space too much. So I had to cut a wire tie, and move the wires out
 the way.

 5) Fitted 10811A at the top.

 6) Invert the counter, and screw in the two screws which secure the
 10811A to the chassis. For this I needed to temporarily move a ribbon
 cable, as the screw was below it.

 7) Powered it up, and it worked. It shows "OVN" in the right of the
 LED display. Once that went out, it still took a minute or two for the
 readings to become pretty stable, although no doubt it will take
 months to become as good as it will get.

 I've not adjusted it yet, as I don't have any accurate frequency
 reference. But whilst the actual frequency indicated on the counter is
 different from what my signal generators are supposed to be produc

Re: [time-nuts] Questionable question about the Lucent RFTGs

[Adrian Godwin]

Do any have the 68332 ? That's got the TPU - Time Processing Unit.
Pretty good at multiple time domains or, in their frequent job as
engine controllers, mixed time/crank angle domains.

On Fri, Dec 5, 2014 at 9:17 PM, Gerhard Hoffmann  wrote:
> Am 05.12.2014 um 21:20 schrieb Hal Murray: d...@dougronald.com said:
>>
>> The 68000 was "just" a CPU.  It didn't have the typical counter/timers (or
>> other IO gear) that are found in many modern chips targeted at the
>> embedded
>> market.  Today, you can probably get everything you need on an Arm SOC.
>> That's ROM/Flash, RAM, counter/timer and UART.
>
> The REF1 unit has the 68331 = 68K CPU with Counter/timers, UART, baudrate
> gen, real time clock,
> watchdog, address decoders, but no onchip memory. Moto's answer to the
> 80186.
>
> And it's got 2 of them, one on the main board and one in the GPS module.
> They are good
> for 16 MHz. High perfomance is different, nowadays.
>
> Gerhard
>
> (back to looking where I can get clean power for my doubler in the REF1)
>
>
>
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[time-nuts] (UK) FS: HP & Agilent 53131A

[Adrian Godwin]

Due to a bulk purchase, I have two used 53131A counters to sell.
Preferably a UK buyer, looking for about £200 + postage. Standard
reference (not medium or high stability), calibration expired.

Please contact me off-list for full details.

-adrian
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Re: [time-nuts] HP 53131A - reset security code

[Adrian Godwin]

I'm the seller. The counters, as a matter of interest, came from the
factory that Rakon recently closed in Lincoln. Unfortunately there wasn't
any contact with the actual staff so I have no information about them.

I bought 3, kept one for myself - the only one with the MS option. I
haven't tried the cal procedure yet so I'm not sure if mine is locked, but
I do have the gear to sniff the eeprom bus so will do that if needed.

Only one thing - two of the counters were HP branded, one was Agilent. I
think the Agilent had later firmware and that's the one that went to
Ulli.   I meant to copy the ROMs before I sent it but forgot, so I may have
different firmware to him. Not sure if that will affect the EEPROM content.

One thing that occurs to me is that car radios of this era had security
codes in them to deter theft. It was generally held that if you lost the
code, putting them in the freezer would temporarily corrupt the codes long
enough to force them back to reset. Maybe something similar would work -
though it's likely that all the other cals would be cleared too. The
trigger thresholds probably aren't too hard, but would the interpolator be
calibrated too ?

On Wed, Dec 24, 2014 at 1:55 AM, Richard Solomon 
wrote:

> Is there some reason you cannot just ask Agilent ??
>
> 73 es HH, Dick, W1KSZ
>
>
>
> On 12/23/2014 6:34 PM, Tom Van Baak wrote:
>
>> Ulli,
>>
>> You're right. The actual procedure is not described in the manual(s):
>>
>> Operating Guide
>> http://cp.literature.agilent.com/litweb/pdf/53131-90055.pdf
>>
>> Programming Guide
>> http://cp.literature.agilent.com/litweb/pdf/53131-90044.pdf
>>
>> Assembly-Level Service Guide
>> http://cp.literature.agilent.com/litweb/pdf/53131-90039.pdf
>>
>> Component Level Information
>> http://literature.cdn.keysight.com/litweb/pdf/5989-6308EN.pdf
>>
>> But I have three ides for you.
>>
>> 1) The last PDF shows U14 is AT28C64B (www.atmel.com/Images/doc0001h.pdf)
>> so if all else fails, you can use a logic analyzer on the address(13) /
>> data(8) pins and see what's in the EEPROM. With some experimentation by you
>> or others on the list we can locate the calibration security. This has the
>> advantage of getting the existing code, without having to clear the entire
>> EEPROM. Some other HP bench instruments use an onboard jumper to override
>> the cal lock, but I don't see that on a 53131A. So perhaps there is a magic
>> front panel sequence or SCPI command to clear NVRAM.
>>
>> 2) Search for 53132 at http://www.ko4bb.com/manuals/index.php and grab
>> the 4 EPROM's. Do a 16-bit merge of U8/U10 and U9/U11 and look for ascii
>> strings. All the SCPI words are in there and not all are documented. For
>> example near the words SYST and CODE and SEC[URITY] is ALL and DEL[ETE].
>> Probably safe to try. Lots of interesting output strings, both for GPIB and
>> for internal debugging. Even the words EEPROM CLEAR, along with "Oooh! That
>> tickles. I don't know that vector." which we also see in the Z3801A, etc.
>>
>> There's also a hidden "SERVICE MENU", complete with Easter egg:
>> MLB TEAM KRISTI BITTNER, LEE COSART, ERIC INGMAN, GARY JACOBSEN,
>> SOOK-LAN LOH, ROB MITCHELL, ROBIN POSKUS, DON SCHREMP, DANA STOFFERS, AND
>> GEORGE TSAI
>>SOFTWARE L. COSART G. JACOBSEN S. LOH R. POSKUS D. STOFFERS
>>HARDWARE K. BITTNER E. INGMAN D. SCHREMP
>>MECHANICAL G. TSAI
>>PROJECT MGR R. MITCHELL
>>BASEHIT -- 53132
>>
>> 3) There's a pForth interpreter in this instrument too. Note
>> pr_eeprom_debug and wr_eeprom.
>>
>> That's enough hints to keep someone on the list (Magnus?) busy over
>> Christmas. Of course, if anyone knows the "confidential procedure", they
>> should just let us know...
>>
>> Thanks,
>> /tvb
>>
>> - Original Message -
>> From: "Mod Mix" 
>> To: 
>> Sent: Tuesday, December 23, 2014 3:04 PM
>> Subject: [time-nuts] HP 53131A - reset security code
>>
>>
>>  Hi,
>>>
>>> I got a used HP 53131A to which I added a stability option board (ocxo).
>>> In order to calibrate the device, a security code is needed - I don't
>>> know it. The seller doesn't know it. It's not the facorty set code.
>>> Advice on how the reset the non-volatile memory would be much
>>> appreciated.
>>>
>>> Thank you very much & happy Christmas
>>>
>>> Ulli
>>>
>>>  From the 53131A service guide:
>>> A calibration security code feature allows you to enter a security code
>>> (electronic key) to prevent accidental or unauthorized calibrations of
>>> the Counter. The security code is set to 53131 or 53132 (corresponding
>>> to the model) when the Counter is shipped from the factory.
>>> If you forget your security code, you can reset the security code to the
>>> model-number default by resetting all of the non-volatile memory to a
>>> default state (Contact Agilent Technologies for this confidential
>>> procedure).
>>> ___
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Re: [time-nuts] 5>10 doubler and old Toko RF catalogue (Cirkit2nd ed. 1994)

[Adrian Godwin]

I think another spinoff from Cirkit was Mainline Electronics of Leicester.
They also mostly disappeared (though I have wondered if they still trade as
the ebay seller anonalouise, who seems to have similar stock).

Mainline Electronics seems to exist as a Russian website, and it looks as
though they have something similar to the Toko range :

http://mainline-group.ru/product-category/coil_transform/moulded/


Barend Hendrikson http://barendh.home.xs4all.nl/Indexeng.htm also has a
useful range of RF components.


On Wed, Jan 28, 2015 at 10:00 AM, David  wrote:

> Andrea, an answer your original Toko data question  below.
>
> >Message: 12
> >Date: Tue, 27 Jan 2015 16:53:07 +0100
> >From: Andrea Baldoni 
> >To: time-nuts@febo.com
> >Subject: [time-nuts] 5>10 doubler and old Toko RF catalogue (Cirkit2nd
> ed.1994)
>
> < cut some stuff>
>
> >Finally I found that a (fairly) complete Toko catalog existed, it was
> sold by
> >Cirkit in '94 and it's not available anymore.
> >Someone has it in PDF form, or want to borrow it to me to scan it?
> >Best regards,
> >Andrea Baldoni
>
> I had a look at the BEC catalogues and they have the same Toko data,
> rather than scan 60 pages or so. You can get what you want with the
> WayBack machine (web archive) to see old Toko data online right now at
> the archived  www.bec.co.uk site, try this for a starter:
>
> http://web.archive.org/web/20041129173623/http://217.34.
> 228.137/PG800/8var/p25.htm
>
> I think BEC (Bonex Electronic Components) followed on from CirKit but
> don't remember if there was a formal connection between the companies or
> not.
>
> Hope that helps, this method to find old data is frequently.
>
> David
> --
>
>
>
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Re: [time-nuts] Lady Heather

[Adrian Godwin]

The ttyS* devices should be owned by root and be in the dialout group, eg

crw-rw---T 1 root dialout 4, 64 Feb 28 08:31 /dev/ttyS0
crw-rw---T 1 root dialout 4, 65 Feb 28 08:31 /dev/ttyS1
crw-rw---T 1 root dialout 4, 66 Feb 28 08:31 /dev/ttyS2
crw-rw---T 1 root dialout 4, 67 Feb 28 08:31 /dev/ttyS3

Rather than chowning them to your username, put your user in the dialout
group.





On Fri, Mar 13, 2015 at 8:47 PM, Dave Mallery 
wrote:

> Lady Heather lives on linux (ubuntu 14-10,  amd64)!
>
> as usual, the serial line connection to COM1 lived up to its reputation for
> stubbornness.
> i have to change the ownership of /dev/ttyS0 back to my username after
> every boot.
>
> previously, i had one of those lil 2-line displays from china.  now i am
> drowning in numbers.
>
>
> did anyone ever document the screen?
>
> many thanks
>
> dave k5en
>
> On Wed, Mar 11, 2015 at 9:07 PM, Dave Mallery 
> wrote:
>
> > thanks Chuck!
> >
> > i will continue the installation process (new machine with quirks).
> >
> >
> >
> > On Wed, Mar 11, 2015 at 7:11 PM, Chuck Harris 
> wrote:
> >
> >> I Do.  She works with wine on linux, and likes it!
> >>
> >> -Chuck Harris
> >>
> >> Dave Mallery wrote:
> >>
> >>> hi
> >>>
> >>> does anyone have the lady running on WINE under Linux??
> >>>
> >>> On Wed, Mar 11, 2015 at 6:13 PM, Paul Berger 
> wrote:
> >>>
> >>>  I have also used LH with a Thunderbolt 'E' and did not have any
> issues,
>  however I have not turned on the E for some time now.
> 
>  Paul
> 
> >>> ___
> >> time-nuts mailing list -- time-nuts@febo.com
> >> To unsubscribe, go to https://www.febo.com/cgi-bin/
> >> mailman/listinfo/time-nuts
> >> and follow the instructions there.
> >>
> >
> >
> >
> > --
> > Dave Mallery, K5EN (ubuntu linux 14.10)
> > PO Box 15  Ophir,  OR  97464
> >
> > no gates...
> >   no windows!
> > free at last!
> >   linux counter #64628 (since 1997)
> >
> > "People aren't as dumb as Microsoft needs them to be."
> > --PJ, May 2007
> >
>
>
>
> --
> Dave Mallery, K5EN (ubuntu linux 14.10)
> PO Box 15  Ophir,  OR  97464
>
> no gates...
>   no windows!
> free at last!
>   linux counter #64628 (since 1997)
>
> "People aren't as dumb as Microsoft needs them to be."
> --PJ, May 2007
> ___
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Re: [time-nuts] Motorola Oncore UT+ firmware upgrade & backup power questions

[Adrian Godwin]

Seiko and some other manufacturers used Supercaps for a while in their
Kinetic watches. Electrically they're fine, but they turned out to have a
shorter life than rechargeable batteries. They even replaced capacitors
with lithium rechargeables when servicing the older models.

In a backup situation they might do better : I believe the problems were
caused by allowing them to discharge and exposing them to high
temperatures, neither of which should occur in a timenut application (as
long as they're not inside a stabilisation oven). However, don't think of
them as a complete solution to ageing nicads - they're still a wet
electrolytic and probably have a finer internal structure than a nicad, so
are still subject to chemical ageing.



On Mon, Mar 16, 2015 at 3:51 AM, Hal Murray  wrote:

>
> csteinm...@yandex.com said:
> > The Energizer AA and AAA lithium primary batteries (Li/FeS2) have a
> shelf
> > life exceeding 10 years,
>
> Like many things, it's temperature dependent.
>
> A classic trick is to store batteries in your freezer.  Aside from better
> shelf life, you can probably find them in the dark.
>
>
> --
> These are my opinions.  I hate spam.
>
>
>
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Re: [time-nuts] Obscure HP T/F instruments in ebay.fr

[Adrian Godwin]

Thanks for the heads-up. Postage to the UK isn't quite so bad, and he
accepted a lower offer ..
The list of other items is well worth a scan, too.

I don't have a reference setup working yet but if there's anyone near
Bedfordshire, UK that would like to do an ADEV plot (just for fun, I'm not
expecting anything amazing) I'd be glad of help.


On Thu, Mar 19, 2015 at 12:55 AM, paul swed  wrote:

> Poul-Henning
> They are interesting the 101 looks pretty nice. Considering the Euro is
> just about a dollar today. $83 US. But then you see the shipping! OK time
> to move on.
> Regards
> Paul
> WB8TSL
>
> On Wed, Mar 18, 2015 at 3:57 PM, Poul-Henning Kamp 
> wrote:
>
> > There is a seller on the french eBay which has some rather old/obscure
> > HP T/F instruments up cheap:
> >
> >   281603533317 HP K05 5060A Linear Phase Detector
> >   281607493683 HP J19 59992A  HP5371A Demonstrator
> >   311298011221 HP 8709A Synchronizer
> >   311307909618 HP 101A 1 MC Highly Stable Quartz Oscillator Reference
> >   311307936107 HP 5275 Time Interval Counter
> >
> > There may be more...
> >
> >
> > --
> > Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
> > p...@freebsd.org | TCP/IP since RFC 956
> > FreeBSD committer   | BSD since 4.3-tahoe
> > Never attribute to malice what can adequately be explained by
> incompetence.
> > ___
> > time-nuts mailing list -- time-nuts@febo.com
> > To unsubscribe, go to
> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
> >
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Re: [time-nuts] Obscure HP T/F instruments in ebay.fr

[Adrian Godwin]

This stuff is lovely, but it's enthusiast's equipment, not public or
commercial museums. There's a great computer museum in Paderborn, Germany -
it's owned by the founder of an ATM company. I love that it has, in
Germany, a really good exhibit about Bletchley Park.

There's a pinball machine museum in Arizona (I think). It burnt down
recently. Again, enthusiasts. Entrance money helps keep it going but it
wouldn't exist without the enthusiasts.

Here in the UK, there are steam museums. Probably elsewhere too.

I grabbed a couple of items from that french auction, fast enough that
there was no bidding war. I wish I'd had more  -  I could easily have
outspent myself but I can't move for stuff as it is. I'd be happy to lend
them to a testgear museum but I don't know of one, at least not in the UK.

The nearest thing I can think of is the Whipple Museum of the History of
Science in Cambridge, UK, which has a mixture of medical and scientific
gear - not really commercial testgear. For timenuts, there's also the Royal
Horological Society's museum which includes a speaking clock, but it's more
about timepiece makers than precision. Also the Harrison clock collection
at Greenwich observatory.


On Fri, Mar 20, 2015 at 11:47 AM, Bob Camp  wrote:

> Hi
>
> Look at the economics of a museum. Count the heads on the payroll.
> Count the paying customers you see times the admission fee.
>
> At least around here most of them have a budget that looks like:
>
> Costs: X
> Money in from visitors: X/10
> Money in from membership fees: X/5
> Money from the gift shop: X/5
>
> They either make up the difference:
>
> 1) From an endowment.
> 2) From government subsidies.
> 3) From other activities (paid research etc).
>
> It's not just electronics that has an issue with this. It's common in
> a lot of fields.
>
> Bob
>
> > On Mar 20, 2015, at 1:33 AM, Bill Hawkins  wrote:
> >
> > There are worse things than breaking up a collection.
> >
> > The Baaken Museum of Electricity in Life, near Minneapolis had a
> > wonderful series of devices that used electricity to examine or prolong
> > life, or to extract money from suckers. About 20 years ago, someone felt
> > that there wasn't enough traffic at the museum, so the interesting
> > exhibits were removed and the museum dumbed down for children. A vampire
> > might greet you at the door.
> >
> > It seems that modern business managers have no time for things that
> > don't draw crowds or fly off the shelves. If a museum or business wants
> > to serve a market niche, it must compete with the incessant blizzard of
> > advertising from the companies that just have to grow. Combine that with
> > such companies expectations of productivity, and no one has time to
> > search for interesting museums, never mind go to national parks.
> >
> > I would have been fascinated by and supportive of the French HP museum,
> > had I known about it. I did not even dream such a place existed, but it
> > makes sense that it was in Europe. Amsterdam has a science museum that
> > lifts children's interest rather than going down to the lowest level to
> > draw more people.
> >
> > In regard to dumbing down, the movie "Idiocracy" seems predictive.
> >
> > Bill Hawkins
> >
> > P.S. The Pavek Museum of Broadcasting (radio) is still hanging on.
> >
> >
> > -Original Message-
> > From: Tom Van Baak
> > Sent: Thursday, March 19, 2015 11:01 PM
> >
> >> If that is the case, then this stuff belongs to a museum and not on
> > ebay. IMHO.
> >
> > Hi Attila ,
> >
> > I completely understand how you feel, but this happens all the time with
> > niche collections. You just can't find a brick and mortar museum
> > interested in taking all that inventory. How many people would travel to
> > city X in country Y to see a collection of electronics made by company
> > Z? So these collections tend to last only as long as the original
> > pioneer behind them is active. Once they are gone, there's a good chance
> > that it all ends up on eBay, scattered around the globe. At least it
> > doesn't end up in recycling or the trash.
> >
> > Checking current vs. completed auctions for that seller, you'll note
> > that a large number of the good or exotic items have already been sold.
> > I noted that high value items like hp rubidium and cesium standards
> > apparently never made it to eBay, suggesting some cherry picking
> > occurred before the collection went out for bid.
> >
> > I once thought "HP should have their own museum". But then they split
> > into Agilent, then Symmetricom bought out their T&F line, then they
> > became Keysight, then Symmetricom became Microsemi. With these
> > companies, there isn't strong technical, moral, or business
> > justification to allocate office space and resources to host dusty
> > museums that might only attract tens or hundreds of people a year. They
> > are rightly focused on current and future products, leaving us bottom
> > feeders and nostalgic historians to collect and display the old 

Re: [time-nuts] Obscure HP T/F instruments in ebay.fr

[Adrian Godwin]

The HP101A and 5275A arrived today. The 101A warmed up in about an hour and
the crystal temp settled. It's now reading 98.50 against my 53131A
(med. stability option but uncalibrated).

I'm not sure what the spec is, or how long ago it was tuned - but even if
it was set recently, it's still survived a DHL truck from france with
little error.



On Sat, Mar 21, 2015 at 8:05 PM, Bill Byrom  wrote:

> Warning: Discussion of old pre-1980 technology follows ...
>
> The Computer History Museum in Mountain View, CA, is amazing. I wish I
> hadn't sold my original issue Commodore PET 2001, but you can find
> examples of this and a wide range of early computers from the
> 1940's/50's/60's/70's (such as SAGE and CDC6400/6600) at the museum:
> http://www.computerhistory.org/ They have an operational Babbage
> Difference Engine No. 2: http://www.computerhistory.org/babbage/
>
> I have worked for Tektronix for 28 years. Many of you may be interested
> in the vintageTEK website: http://www.vintagetek.org/ For those of you
> who have read old Tektronix service manuals with schematics:
> http://www.reprise.com/host/tektronix/humor/
>
> Only a few of us existing Tektronix employees have been with the company
> long enough to have been involved in selling and supporting analog CRT
> oscilloscopes, TM500/TM5000 modular equipment, and the Tek
> 4051/4052/4054 (first all-in-one graphic desktop computers). Some of
> these were obsolete years before I started Tek in 1987, but I was using
> them in the late 1970's.
>
> When I was a University of Texas Electrical Engineering student back in
> the mid-1970's I built a device to compare the 3.5795454 MHz color burst
> NTSC television signal (from a normal TV set color reference oscillator)
> to an ovenized 5 MHz crystal oscillator using a 315/88 ratio TTL divider
> in the PLL. I used my Tektronix government surplus RM45A + CA plugin
> oscilloscope for this project. I also experimented with WWV 5/10/15 MHz
> frequency comparisons, but in Austin Texas the propagation from Ft
> Collins CO made this difficult to much better than 1 part in 10^7. The
> color burst method let me make use of the major TV network's rubidium
> standards. Unfortunately, by the late 1970's the networks were reading
> the monthly time deviation reports from NBS (name of NIST before 1988),
> and they would often manually readjust their rubidium standard magnetic
> field to get the frequency error in the NBS comparison closer to zero.
> Of course, this made the reliability of the time dissemination (phase of
> the color burst signal) unreliable. If they had just let the rubidium
> standard alone in a stable environment with no temperature or magnetic
> field changes, the drift in the timing error could have been modeled and
> corrections to the received signal made before reading the NBS monthly
> error reports.
>
> In my first job (late 70's to early 80's) we used Tektronix 7000 series
> CRT scopes to compare the output of a Tracor rubidium standard with a
> WWVB receiver and reference clocks in test instruments we were
> calibrating. We were considering building a commercial product based on
> my color burst recovery technique, but the random frequency adjustments
> by the networks and the switching between network and local station
> color burst reference clocks during local programming insertion caused
> us to abandon this project. This was about 7 years before I started at
> Tektronix.
>
> --
> Bill Byrom N5BB
>
>
>
> On Fri, Mar 20, 2015, at 12:02 PM, Robert LaJeunesse wrote:
> > While it may not be time-nut centric there is a great museum in
> > Michigan that has collections of both clocks and technology, along
> > with a couple Stradavarius violins and machinist tools used by Mr.
> > Daimler. The Henry Ford Museum in Dearborn, MI has been actively
> > enlarging their technology collection - having recently paid nearly $1
> > million for an original Apple I built by Jobs & Wozniak. They also
> > have Robert Moog's prototype music synthesizer. Might be time to
> > interest them in adding precision time to their clock and technology
> > collections.
> >
> > Bob LaJeunesse
> >
> >> Sent: Friday, March 20, 2015 at 1:33 AM From: "Bill Hawkins"
> >>  To: "'Tom Van Baak'" ,
> >> "'Discussion of precise time and frequency measurement'"
> >>  Subject: Re: [time-nuts] Obscure HP T/F
> >> instruments in ebay.fr
> >>
> >> There are worse things than breaking up a collection.
> >>
> >> The Baaken Museum of Electricity in Life, near Minneapolis had a
> >> wonderful series of devices that used electricity to examine or
> >> prolong life, or to extract money from suckers. About 20 years ago,
> >> someone felt that there wasn't enough traffic at the museum, so the
> >> interesting exhibits were removed and the museum dumbed down for
> >> children. A vampire might greet you at the door.
> >>
> >> It seems that modern business managers have no time for things that
> >> don't draw crowds or fly off the shelves. If a museum 

Re: [time-nuts] Another Philipe Patek clock

[Adrian Godwin]

There have been large numbers of master clocks in the broadcasting house
clearance auctions over the last year. As a result there are probably quite
a lot in circulation in the UK right now, though the BBC cachet put the
prices above dirt-cheap. The studio slave clocks were particularly popular.

I'm not sure if there are any more auctions in the series, but the
auctioneer is Peaker Pattinson.

On Mon, Mar 30, 2015 at 5:39 PM, Bruce Hunter via time-nuts <
time-nuts@febo.com> wrote:

> Didn't the BBC surplus a number of similar units, along with the slaves a
> few years ago?
>
> Bruce, KG6OJI
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Re: [time-nuts] Ultra High Stability Time Base Options for 53132A

[Adrian Godwin]

What caused that degradation ? I'm interested in dos/don'ts for best use of
a 10811.



On Sat, Apr 11, 2015 at 11:32 PM, Richard (Rick) Karlquist <
rich...@karlquist.com> wrote:

> On 4/11/2015 5:01 AM, J. L. Trantham wrote:
> Unless the design has been changed, the 10811 option
> for the 53132 has poor short term stability and
> degrades the performance of the 10811 by something
> like an order of magnitude.  I complained about
> this when the counter first came out 25 years
> ago but no one would listen.  At the time I had
> recently transferred out of counter R&D to work
> on the 5071A.
>
> Rick Karlquist N6RK
>
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Re: [time-nuts] A Open Source GPIB project

[Adrian Godwin]

Looks to be Protel aka Altium for the schematics / pcb.

On Sun, Apr 26, 2015 at 2:42 PM, Bob Camp  wrote:

> Hi
>
> After poking around a bit, more questions that comments.
>
> 1) It looks pretty cool.
> 2) Any idea of what the tool chain was that generated the files? (I
> probably need viewing programs that I don’t have)
> 3) Do they have any plans to bring up the doc’s in English? (even if only
> through a translation program)
>
> Once they get the stuff running, I suspect there will be a lot of
> questions about interfacing it to things
> like TimeLab.
>
> Bob
>
> > On Apr 25, 2015, at 11:42 PM, Hui Zhang  wrote:
> >
> > Hi:
> >
> > Here is a open source GPIB project that developed by some Chinese
> amateurs, the developer released all of the information about hardware and
> software, including circuit diagram, PCB diagram, firmware source code,
> communication protocol and upper computer PC program (late on). The project
> name is CARE.If you are interested you can build your own CARE, but please
> don’t use this open source project for commercial purpose.
> >
> >
> > Specifications:
> >
> > WiFi  expand interface （6 IOs + 3.3V power supply）
> >
> > Sensor expand interface (2 IOs + 3.3V power supply)
> >
> > j-link SWD mode interface
> >
> > TF Card slot
> >
> > RJ-45 connector (100Mbps)
> >
> > USB (via CP2102 connect to LPC1768, can be set to ARM inside USB connect
> by jumper)
> >
> > Mode Switch (Online or offline acquire)
> >
> > MCU: LPC1768
> >
> > USB TO 232: CP2102
> >
> > Network PHY: LAN8720A
> >
> > Temperature sensor: DS18B20, DHT22 and other model single bus sensor
> will be support at late version.
> >
> > GPIB interface chip: SN75160，SN75162
> >
> > PCB size：60mm*100mm
> >
> >
> >
> > CARE firmware:  https://git.oschina.net/gpib/CARE.git
> >
> > Upper Compter program: https://git.oschina.net/xknife/MonitorKnife.git
> (Under Construction)
> >
> > Circuit diagram and PCB: https://git.oschina.net/gpib/CARE-DXP.git
> >
> > BOM list: http://bbs.38hot.net/forum.php?mod=viewthread&tid=115514
> BOM_GPIB.rar
> >
> > (will put file in GIT late)
> >
> >
> >
> > Protocol mode:
> >
> > 1, Transport protocol transfer mode, the GPIB address of equipment can
> be user define of LAN USB and WIFI port
> >
> > 2, The developers defined GPIB protocol, support multi-address and
> multi-equipment, the protocol file is (so far, only Chinese language
> version)
> >
> > http://bbs.38hot.net/forum.php?mod=viewthread&tid=115514
> >
> > Care通讯协议说明-b1.v150410.2.rar
> >
> >
> >
> > Testing tool”
> >
> > 1, Some Serial port tools like as sscom 3.2; send HEX or ASCII command
> to CARE via serial port;
> >
> > 2,TPC&UDP testing tools, send control or SCPI command to CARE via
> Ethernet port;
> >
> > 3,ASCII code converting tool
> >
> >
> >
> > The project is not over, so far, the hardware part is OK, but the code
> of offline acquire and Talk Only function is not finish. (coming soon….),
> some various equipments were tested by SCPI or old HP GPIB command, they
> work very well.
> >
> >
> >
> > The Care Project Post in Chinese 38hot forum, many pics:
> >
> > http://bbs.38hot.net/forum.php?mod=viewthread&tid=115514
> >
> >
> >
> > This open source project can't be used for commercial purpose.
> >
> > The main developer’s email: guangz...@163.com
> >
> > Have a fun!
> >
> >
> > Hui Zhang /BA6IT
> > ___
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Re: [time-nuts] EMI and CE certification

[Adrian Godwin]

Is it driven as  an inductive loop? That might put it under different
regulations.
On 11 May 2015 17:47, "Chuck Harris"  wrote:

> Yes, but in the case of the lawnmower fence, and the
> invisible dog fence, the transmitter drives the fence
> as an antenna.
>
> In the US, the antenna size for "free bands" is seriously
> limited.  As an example, the so called "Lowfer" band at
> 136KHz is limited to antennas no larger than 15m in length.
>
> And, that is one of the larger limitations.
>
> 15m would encircle only a very small lawn.
>
> OBTW, I realized on reading my post below, that I was very
> unclear on what could "be foiled."  I meant that the
> operating permission for the lawnmower system could probably
> be foiled by looking into the maximum antenna lengths for
> unlicensed services of this sort, in this frequency range.
>
> I would quite imagine that any certification they may have
> is for the transmitter and receiver, without an antenna.
>
> -Chuck Harris
>
> Alex Pummer wrote:
>
>>
>>
>> yes for transmitter  antennas, but not for receiver antennas in Austria
>> Germany
>> Switzerland France Hungary one could have receiver antenna as long as he
>> want, but
>> the height is limited similarly as in the US
>> 73
>> KJ6UHN
>> Alex
>>On 5/10/2015 7:15 AM, Chuck Harris wrote:
>>
>>> My recollection is that in the US, certain requirements
>>> exist for antenna length on the so called "free bands".
>>>
>>> I have no idea what the European requirements might be,
>>> but, perhaps they can be foiled by their allowing their
>>> minuscule amounts of power to flow into an over length
>>> antenna?
>>>
>>> -Chuck Harris
>>>
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Re: [time-nuts] Small time server for mobile use.

[Adrian Godwin]

I hesitate to say this for fear of provoking a fault, but although I
wouldn't consider them especially good, they're not universal failures. I
have a Pi running a house control and logging system that has an uptime of
230 days despite being largely unattended (I'm not on site - it doesn't get
any special treatment). It doesn't have a read-only filesystem, however all
logs are written to a USB stick.



On Sun, May 24, 2015 at 4:07 PM, Frister  wrote:

> I've noticed that on my RPI as well,
> Time stability improved greatly when connected to a simple and well
> cooled 7805 voltage
> regulator. My RPI (GPS PPS) runs at about +/- 2 uS on a somewhat
> medium CPU sytem
> load. Good enough for my needs.
>
> Frits
>
> On 5/24/15, Attila Kinali  wrote:
> > On Wed, 13 May 2015 09:07:44 -0500
> > bownes  wrote:
> >
> >
> >> For the advocates of RPi solutions, I put about half a dozen in to
> support
> >>
> >> some non mission critical infrastructure about a year ago. We are using
> >> them
> >> for for logging, reading QR codes, running a vending machine, kiosk web
> >> browsers, and similar tasks. In short, nothing requiring heavily
> lifting.
> >>
> >>
> >> I've been incredibly dissappointed in the results. Well over half of
> them
> >>
> >> have needed replacement and not a one runs reliably. They need rebooting
> >> at
> >> intervals from hours to a few tens of days to recover from total lock
> up.
> >>
> >> The problem is not environmental, power or SD cards.
> >
> > Do you know what the problem is?
> >
> > I know that the RPI has pretty cheap design (like most of these
> super-cheap
> > SoC boards) and does suffer from a few problems. The most common one
> > is under-designed power supply. Together with the ultra-cheap wall-wart
> > supplies mostly used results in a quite decreased MTBF due to
> spikes/drops
> > on the power rails (BTW: soekris suffers from that too, just that a
> better
> > wall-wart supply doesn't help). Depending on the environment, in which
> > those boards are run, overheating might also be a problem.
> >
> > Other than that, i am not aware of any software or hardware issues that
> > would cause the RPI, or any other board, to run unreliably.
> >
> >   Attila Kinali
> > --
> > < _av500_> phd is easy
> > < _av500_> getting dsl is hard
> > ___
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> > and follow the instructions there.
> >
>
>
> --
> vbradio.wordpress.com
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Re: [time-nuts] Thunderbolt power connector crimper

[Adrian Godwin]

The PA-09 crimp tool will do a lot of smaller crimps, even the small JST
sizes. There's also a bigger one available.

http://www.ebay.co.uk/itm/261046260247?ru=http%3A%2F%2Fwww.ebay.co.uk%2Fsch%2Fi.html%3F_nkw%3D261046260247%26_rdc%3D1

On Mon, Jun 8, 2015 at 12:53 PM, George Dubovsky  wrote:

> I had not realized that those ubiquitous AMP crimpers of yore were now ebay
> curiosities, but this is what I was referring to in my earlier e-mail:
>
> <
>
> http://www.ebay.com/itm/Amp-Engineer-Service-Tool-II-Crimper-/231586917342?pt=LH_DefaultDomain_0&hash=item35eba7ebde
> >
>
> 73,
>
> geo - n4ua
>
> On Mon, Jun 8, 2015 at 7:44 AM, George Dubovsky  wrote:
>
> > Hi Matt,
> >
> > Any of the AMP Service Tools - I have the I and II - will work. Positions
> > A and B (for the conductor and the insulation respectively) on Service
> Tool
> > I or E and B on Service Tool II will work nicely. I suspect there are
> lots
> > of other "generic" crimpers that will do the job as well. Heck, for just
> > one connector, needle-nose pliers, a good magnifier, a soldering iron,
> and
> > a dictionary of curse words will suffice... ;-)
> >
> > Good luck.
> >
> > 73,
> >
> > geo - n4ua
> >
> > On Mon, Jun 8, 2015 at 6:29 AM, Matt Robert 
> wrote:
> >
> >> Hi Guys,
> >>
> >> I am currently in the process of completing my Thunderbolt project and I
> >> need to find a suitable crimper to attach wires to the pins that go
> inside
> >> the power connector.
> >>
> >> The only reference I can find is on this page here (
> >> http://www.prc68.com/I/ThunderBolt.shtml) that talks about the official
> >> Molex tool which is scarily expensive, and the page also mentioned a
> >> Radioshack tool that I can't find any further details on.
> >>
> >> Can someone please point me in the right direction of a suitable crimper
> >> for the Molex 538-16-02-0103 pins.
> >>
> >> Cheers,
> >> Matt
> >> VK2LK
> >> ___
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> >
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Re: [time-nuts] magnetic electronic components

[Adrian Godwin]

Although it's published by a vendor, this applications manual has a lot of
useful information.

http://www.we-online.com/web/en/electronic_components/produkte_pb/fachbuecher/Trilogie.php

I was sufficiently impressed when I saw it at a trade show that I bought a
copy, and they've reduce the price since then.


On Mon, Jun 22, 2015 at 8:02 PM, Attila Kinali  wrote:

> Hi,
>
> I was looking up some stuff and realized (again) that I don't know
> anything about how magnetic electronic components (inductors/solenoids,
> transfomers, baluns, ferrite beads...) work. Yes, I can calculate
> the inductance, I know how to get from the AL value to number of
> windings. But I don't know anything about the practical issues
> or where they come from. Unfortunatelly, this knowledge seems to
> generally rare among EEs (at least everyone I asked in the last
> couple of years) and books about it are either long out of print
> (with no pdf available) or more geared towards the physics student.
>
> So, does anyone have any recomendation where I could read up
> on this? Books, pdfs, webpages,... anything.
>
> Also something that covers more the application side, ie how to
> use ferrite beads/toroids to build devices, would be appreciated.
>
> Thanks in advance
>
> Attila Kinali
>
> --
> I must not become metastable.
> Metastability is the mind-killer.
> Metastability is the little-death that brings total obliteration.
> I will face my metastability.
> I will permit it to pass over me and through me.
> And when it has gone past I will turn the inner eye to see its path.
> Where the metastability has gone there will be nothing. Only I will remain.
>
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Re: [time-nuts] wtd: WWVB info...

[Adrian Godwin]

I have a very similar looking Junghams clock bought in the UK about 20
years ago (though it doesn't have that time zone graphic). It works off the
UK MSF standard : still in daily use, though it doesn't sync quite so well
since the transmitter moved to Cumbria (I'm quite close to the old site,
Rugby).

On Fri, Aug 7, 2015 at 4:44 AM, Alexander Pummer  wrote:

> a software demodulator for the DCF77 was published last year, the DCF77
> has similar modulation structure as the new wwvb it was developed at a
> Swiss company
> 73
> KJ6UHN
> Alex
>
>
> On 8/6/2015 3:11 PM, Donald wrote:
>
>> I have found this old posting from 2014:
>> https://www.febo.com/pipermail/time-nuts/2014-August/086043.html
>>
>> Ivan Cousins states:
>> "A WWVB receiver can now be done on an Arduino microprocessor with a
>> little help from an antenna. "
>>
>> Googleing has not found such an article or project.
>>
>> Has this ever happened ?
>>
>> Is Ivan still around and can he shed light on this topic.
>>
>> Thanks
>> Don
>>
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>
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Re: [time-nuts] wtd: WWVB info

[Adrian Godwin]

The difficult thing about that is that making the wifi connection without
any user interface is difficult now that most wifi connections have
security enabled.

On Tue, Aug 11, 2015 at 8:14 AM, Chris Albertson 
wrote:

> You might look into GPS devices.  They aren't quite as cheap as the WWVB
> > chips, but there are lots of them on the market.
>
>
> Yes GPS receivers can be very cheap and self contained and much easier yo
> use than those WWVB chips.  I have two of the chips.  I don't think they
> work now that WWVB has changed format and even back in the day they only
> worked for a few hours at night.  GPS is better.
>
> But there is another good source for correct time.  Most people today have
> WiFi in their house, at school and at work.  If the clock is going into an
> area where WiFi  is available then it can connect to NTP.If the clock
> connects to WiFi you can save money and parts count by not needing any
> physical controls on the clock for setting or to control options as all
> that can be done from a smart phone's web browser
>
> --
>
> Chris Albertson
> Redondo Beach, California
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Re: [time-nuts] KS-24361 REF-0 standalone

[Adrian Godwin]

These seem a good deal but the shipping price to the UK puts me off a bit -
it's 3 x the price of the unit.

I've looked into shipping a number of them to get a better rate and it
seems worthwhile. I'm happy to sell them on to time-nuts at cost (will
include shipping and duty) and ebay the remainder.  Would anyone be
interested ?

-adrian


On Mon, Aug 10, 2015 at 2:47 PM, paul swed  wrote:

> Dan
> A really nice blog even with colored dots on the pins. Can't get much
> better then that. Fantastic on the strings that are needed to keep the Ref
> 0 happy and there timing.
> Regards
> Paul
> WB8TSL
>
> On Mon, Aug 10, 2015 at 7:16 AM, Bob Camp  wrote:
>
> > Hi
> >
> > Yes, Paul posted a link yesterday that includes a link of the words dump
> > from
> > pForth.
> >
> > Bob
> >
> >
> > > On Aug 9, 2015, at 9:51 PM, Don Latham  wrote:
> > >
> > > Excellent. The words can be dumped to give a better idea about what's
> > going on?
> > >
> > > Bob Camp
> > >> Hi
> >
> > ___
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> >
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Re: [time-nuts] KS-24361 REF-0 standalone

[Adrian Godwin]

I've ordered some. Please contact me directly rather than via the list if
you're interested in one or more. The seller will repackaged them to reduce
shipping so they won't be boxed quite as advertised but should be good
enough.


On Wed, Aug 12, 2015 at 12:16 AM, Bob Camp  wrote:

> Hi
>
> I suspect that postage throughout Europe would be much better after a bulk
> transit over the ocean. The units are already (or maybe better put still)
> packed in
> air shipping boxes with “Korean Air” tags on them. The seller then
> re-boxes those
> inside another box. I would not have any real fear of them not making the
> trip over
> the ocean in fine shape. Once they get there, you should be able to
> re-label the
> original boxes and mail them out. Certainly not a “no hassle” deal, but
> pretty
> simple as these things go.
>
> Bob
>
> > On Aug 11, 2015, at 4:15 PM, Adrian Godwin  wrote:
> >
> > These seem a good deal but the shipping price to the UK puts me off a
> bit -
> > it's 3 x the price of the unit.
> >
> > I've looked into shipping a number of them to get a better rate and it
> > seems worthwhile. I'm happy to sell them on to time-nuts at cost (will
> > include shipping and duty) and ebay the remainder.  Would anyone be
> > interested ?
> >
> > -adrian
> >
> >
> > On Mon, Aug 10, 2015 at 2:47 PM, paul swed  wrote:
> >
> >> Dan
> >> A really nice blog even with colored dots on the pins. Can't get much
> >> better then that. Fantastic on the strings that are needed to keep the
> Ref
> >> 0 happy and there timing.
> >> Regards
> >> Paul
> >> WB8TSL
> >>
> >> On Mon, Aug 10, 2015 at 7:16 AM, Bob Camp  wrote:
> >>
> >>> Hi
> >>>
> >>> Yes, Paul posted a link yesterday that includes a link of the words
> dump
> >>> from
> >>> pForth.
> >>>
> >>> Bob
> >>>
> >>>
> >>>> On Aug 9, 2015, at 9:51 PM, Don Latham  wrote:
> >>>>
> >>>> Excellent. The words can be dumped to give a better idea about what's
> >>> going on?
> >>>>
> >>>> Bob Camp
> >>>>> Hi
> >>>
> >>> ___
> >>> time-nuts mailing list -- time-nuts@febo.com
> >>> To unsubscribe, go to
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> >>> and follow the instructions there.
> >>>
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Re: [time-nuts] KS-24361 REF-0 standalone

[Adrian Godwin]

Thanks for doing these write-ups.

I've bought several units from the US supplier with the intention of
getting shipping down to a sensible level, and have a lash-up based on your
article which has had all the first few running. They won't lock to
anything far off 1pps so need a properly working receiver or source
(perhaps another ref-0) to test. An attempt to generate a 1pps signal from
the micro as a quick test was a failure - too much variation or error for
the loop to track.

I'd also like to use the spare space inside the box - I'm planning to mount
a beaglebone black there as a self-contained NTP server and reference
source.The BBB can run gpsd to accept a wide range of receivers and supply
the packets to the ref-0 with or without actual data. Perhaps your pcb
design could allow for a suitable header as an alternative to the inboard
micro.

I'm don't yet know what receiver to choose : I'm currently using it with a
Symmetricon 58534A  and also have some Oncore modules which will, of
course, fit neatly in the box.

I'm also interested in what could to be done to the 10MHz output. Bob has
mentioned that it's not ideal but I'm not sure how to evaluate it or clean
it up. Maybe that's a different project that would appeal to someone else
here.


On Mon, Aug 31, 2015 at 3:53 AM, Daniel Watson 
wrote:

> All,
>
> I hope some more of you have had luck getting your REF-0s running
> standalone.
>
> My earlier write-ups were focused on the bare minimum connections and code
> needed to make a REF-0 work. Of course, external connections are not ideal
> for long-term operations. The real end-state here is to have a nice board
> with a modern GPS that will install cleanly inside the REF-0. I have
> completed another write-up showing my work toward that goal. I show how you
> can access all of the necessary pins on the REF-0 directly on the board,
> without using the external Interface connector. I also show a simple
> prototype of my custom REF-0 GPS board.
>
> Here's the write-up:
>
>
> http://syncchannel.blogspot.com/2015/08/prototyping-gps-board-for-ks-24361-ref-0.html
>
>
> If you just want to solder something together, you can easily house your
> microcontroller and GPS on some protoboard as I did. This is the protoboard
> I used, it fits almost perfectly where a real Oncore GPS would go. I just
> had to widen the mounting holes with a drill.
>
>
> http://www.amazon.com/10Pcs-Double-Sided-Protoboard-Prototyping/dp/B00NQ387TY
>
>
> Beyond the prototype though, I personally want a nice PCB with a Ublox on
> it for my REF-0s. I plan to work on that as I have time. Though now that my
> summer break is over, time is a bit harder to find. :)
>
>
> Regards,
>
> Dan W.
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Re: [time-nuts] New Symmetricom 58532A antennas - Launch3

[Adrian Godwin]

I shipped a bunch of ref-0 units to the UK. Saved a huge amount of shipping
by buying a lot. It might not be much more expensive to ship 10 than 1.

There are still a couple of patient folk on this list waiting for me to
ship them on (or maybe they've given up waiting for me to be less busy).




On Fri, Oct 2, 2015 at 6:30 PM, Lists  wrote:

>
> > On 2 Oct 2015, at 01:05, Daniel Watson  wrote:
> >
> > Thanks for passing this along. That's quite a good price, assuming the
> shipping is reasonable.
>
> Well they wanted $65 to ship one to the UK, so I didn’t bother, I guess
> shipping in the US will be cheaper!
>
> Chris
> G1FEF
>
>
>
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Re: [time-nuts] New Symmetricom 58532A antennas - Launch3

[Adrian Godwin]

There's a drawing on the spec sheet. It's just a bit of 1 5/8 tube. Try a
local aerial fitter.


On Fri, Oct 2, 2015 at 2:01 PM, Steve  wrote:

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

[Adrian Godwin]

I have a synchronome clock built for the British Post Office.

I find that the 10V or so that a USB to serial adapter can produce can
trigger the solenoid, if allowed to charge a capacitor for the intervening
minute. The effect is that I can print a single character once a minute at
a low bit rate and, with a few components but no power supply beyond USB,
step the clock.

A better solution would include a microcontroller to remember where the
hands had stepped to, for automatic recovery after a stoppage.


On Fri, Oct 16, 2015 at 1:25 AM, Brooke Clarke  wrote:

> Hi Don:
>
> I've got a number of SWCC clocks and 3V doesn't work for any of them.
> I've done a number of experiments and a higher voltage and series resistor
> makes a huge improvement.
>
>
> Mail_Attachment --
> Have Fun,
>
> Brooke Clarke
> http://www.PRC68.com
> http://www.end2partygovernment.com/2012Issues.html
> http://www.prc68.com/I/DietNutrition.html
> Don Couch wrote:
>
>> Hi, Brooke,
>>
>> My self winding clock synchronizes fine on three volts. I built a
>> synchronizer using a PIC controller with a 32KHz quartz crystal, running on
>> three volts. You might want to carefully check the coil and connections on
>> yours. By the way, the winding coils also are running on three volts.
>>
>> Don Couch
>>
>> On 10/14/2015 11:02 AM, Brooke Clarke wrote:
>>
>>> Hi Nick:
>>>
>>> One of my Self Winding Clock Co. (WU) clocks was taken down yesterday
>>> for painting.
>>> When put up one of the Ken's Clock Synchronizers was installed and the
>>> hands moved to align with the heart shaped cam it uses, but it never worked.
>>> The problem was it used a 4.5 Volt signal which can develop the current
>>> needed to pull the sync electromagnet the time constant is far too slow.
>>> I'm going to add a high voltage circuit with series resistor to get the
>>> time constant down one or two orders of magnitude.  The key to this is a
>>> PCB I make that holds 5 each 9V batteries connected in series, so I'll use
>>> one, two or more of them to get the time constant down.
>>> http://www.prc68.com/P/45VS.html
>>>
>>> Before I had the 45 Volt Stick I was considering getting the needed high
>>> voltage by charging a cap a minute or two before the top of the hour and
>>> discharging it through a resistor.  Here's a video showing that would work.
>>> http://www.prc68.com/I/SWCC.shtml#Experiments_Feb_2014_
>>>
>>> Mail_Attachment --
>>> Have Fun,
>>>
>>> Brooke Clarke
>>> http://www.PRC68.com
>>> http://www.end2partygovernment.com/2012Issues.html
>>> http://www.prc68.com/I/DietNutrition.html
>>> Nick Sayer via time-nuts wrote:
>>>
 On Oct 14, 2015, at 4:42 AM, billriches 
> wrote:
>
> Not milisecond time distribution but time related!
>
> In the early half of the 1900s Western Union was in the time
> business.  They
> would rent businesses such as banks, office buildings, etc clocks for
> a few
> dollars a month.  These were pendulum wall clocks that had 2 #6 dry
> cell
> batteries inside that would wind them every hour or so. The clocks were
> connected to the WU telegraph line and for a minute before and after
> the
> top of the hour all traffic on the circuit would stop. Exactly at the
> top
> of the hour they would push a pulse of 50 ? volts or so over the line
> and it
> would reset the clock to the top of the hour.
>
 The WU standard time service goes back further than the turn of the
 20th century. It started in 1870.

 I’ve always wanted to get my hands on one of those clocks and come up
 with a circuit to recreate the synchronization signal for it, probably with
 a Raspberry Pi running ntpd and a big ol’ MOSFET. The problem is that at
 this point, those clocks are quite expensive once they’re reconditioned.

 My understanding (perhaps incorrect) was that the sync pulse was once
 daily and, as you said, would cause the hands to “snap” to 12. The trailing
 edge of the pulse was synchronized and would release the clock to operate
 normally.

 That they had something as accurate and widespread as it was so early
 is astonishing.
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>>>
>>
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[time-nuts] Tait reference

[Adrian Godwin]

Are these the references with a rubidium oscillator ? They seem to have
similar models with OCXOs etc.

http://www.ebay.co.uk/itm/111862884745
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Re: [time-nuts] Tait reference

[Adrian Godwin]

Yes, i found that description and it put me off buying one. But there are
also references on the web (including time-nuts archive) to surplus T801s
with rubidium sources.

Anyway, I took a punt and bought one.
So I'll find out soon :).


On Mon, Jan 11, 2016 at 11:18 AM, Charles Steinmetz 
wrote:

> Adrian wrote:
>
> Are these the references with a rubidium oscillator ? They seem to have
>> similar models with OCXOs etc.
>>
>
> Tait is a manufacturer of mobile communications gear in New Zealand.  The
> T801 was part of a discontinued "quasi-synchronous communications system"
> -- a form of simulcasting on the same frequency by transmitters at
> different locations, to fill in dead spots.  Tait's application was utility
> and public service mobile radios (not radio broadcasting, where this scheme
> has also been used).  Here is Tait's basic description:
>
> The Tait Quasi-Synchronous Communication System works by broadcasting
>> simultaneously from several transmitters on the same frequency. The
>> transmitters then operate as a single transmitter giving superior coverage.
>>
>> A Tait T801 Frequency Referenct Module acurately maintains the frequency
>> of the transmitters at each site.
>>
>> Where required, the T801 allows small frequency offsets to prevent the
>> occurrence of static nulls in the overlap area.
>>
>> The T801 module may be driven from one of a number of frequency
>> references, such as:
>> -- Rubidium frequency standard
>> -- Broadcast frequency standard
>> -- Oven Controlled Crystal Oscillators (OCXOs)
>> -- GPS Caesium Clock
>>
>
> This suggests that the T801 does not have an internal frequency reference,
> but rather requires a precision external reference to function.  (It has a
> jack labeled "INTERNAL STD OUTPUT," but that may simply be a reference that
> is derived from the external standard, or a backup crystal oscillator to
> keep the transmitter more or less on frequency if the external reference
> signal is lost.)
>
> Best regards,
>
> Charles
>
>
>
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Re: [time-nuts] Tait reference

[Adrian Godwin]

If so, let's hope the sudden surge of purchases will encourage the dealer
to find some more :)


On Tue, Jan 12, 2016 at 1:39 PM, Clint Jay  wrote:

> That's a very happy coincidence and one I'd hoped to hear.
>
> The pictures in the auction seem to show a lack of tarnish on the Ref Out
> and Ref In BNCs which suggests they have had plugs on them, looping the
> internal reference, other little bits of information also pointed to that,
> the remnants of a sticker on the front of one unit seems to say
> 'RUBID01...', past auctions of T801 units have been labelled with things
> like 'RUBID048', the hex switches seem to be set correctly for use with an
> internal reference as well so I was quietly confident they had the Rb
> option fitted.
>
> Now I just have to cross my fingers that mine arrive with the Rb in good
> conditon. The seller also states 'working order' so there's possible scope
> for a refund if it doesn't.
>
> On 12 January 2016 at 12:24, GandalfG8--- via time-nuts <
> time-nuts@febo.com>
> wrote:
>
> > Are these the references with a rubidium oscillator ?  They seem  to
> have
> > similar models with OCXOs etc.
> > http://www.ebay.co.uk/itm/111862884745
> >
> > ---
> > Well now, how's this for a happy coincidence.
> >
> > I've just received an email from a friend who bought a Tait T801 from
> that
> > very same auction, asking about the rubidium module that he  found inside
> > it:-)
> >
> > Regards
> >
> > Nigel
> > Gm8PZR
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> >
>
>
>
> --
> Clint.
>
> *No trees were harmed in the sending of this mail. However, a large number
> of electrons were greatly inconvenienced.*
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and follow the instructions there.

Re: [time-nuts] Tait reference

[Adrian Godwin]

Good news - my purchase arrived quickly, contains an FE5660A 10MHz
oscillator and shows both the internal standard lock light and the internal
reference lock light within a few minutes. It runs from 13.8 volts and
takes about 1.2A.

The f1 and f2 lock lights don't come on, but that's not a big issue. I may
just rewire those outputs as a distribution amplifier in any case.


On Tue, Jan 12, 2016 at 5:46 PM, Adrian Godwin  wrote:

> If so, let's hope the sudden surge of purchases will encourage the dealer
> to find some more :)
>
>
> On Tue, Jan 12, 2016 at 1:39 PM, Clint Jay  wrote:
>
>> That's a very happy coincidence and one I'd hoped to hear.
>>
>> The pictures in the auction seem to show a lack of tarnish on the Ref Out
>> and Ref In BNCs which suggests they have had plugs on them, looping the
>> internal reference, other little bits of information also pointed to that,
>> the remnants of a sticker on the front of one unit seems to say
>> 'RUBID01...', past auctions of T801 units have been labelled with things
>> like 'RUBID048', the hex switches seem to be set correctly for use with an
>> internal reference as well so I was quietly confident they had the Rb
>> option fitted.
>>
>> Now I just have to cross my fingers that mine arrive with the Rb in good
>> conditon. The seller also states 'working order' so there's possible scope
>> for a refund if it doesn't.
>>
>> On 12 January 2016 at 12:24, GandalfG8--- via time-nuts <
>> time-nuts@febo.com>
>> wrote:
>>
>> > Are these the references with a rubidium oscillator ?  They seem  to
>> have
>> > similar models with OCXOs etc.
>> > http://www.ebay.co.uk/itm/111862884745
>> >
>> > ---
>> > Well now, how's this for a happy coincidence.
>> >
>> > I've just received an email from a friend who bought a Tait T801 from
>> that
>> > very same auction, asking about the rubidium module that he  found
>> inside
>> > it:-)
>> >
>> > Regards
>> >
>> > Nigel
>> > Gm8PZR
>> > ___
>> > time-nuts mailing list -- time-nuts@febo.com
>> > To unsubscribe, go to
>> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> > and follow the instructions there.
>> >
>>
>>
>>
>> --
>> Clint.
>>
>> *No trees were harmed in the sending of this mail. However, a large number
>> of electrons were greatly inconvenienced.*
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Re: [time-nuts] Generating a solid PPS from 10Mhz source

[Adrian Godwin]

Why use a board full of TTL when an $1 8-pin chip will do it ?


On Thu, Jan 14, 2016 at 11:44 PM, Morris Odell 
wrote:

> Am I missing something here?
>
> I understand the ease and fun of programming up an AVR as much as anyone
> but surely this task could be accomplished  easily with a chain of fast
> synchronous TTL or CMOS dividers. A resynchronising FF could also be added
> at the end to  clean up the 1 pps if required. You wouldn't need to worry
> about the maths or OBOBs either.
>
> Admittedly you would need more PCB real estate but that shouldn't be a big
> deal in most cases.
>
> Morris
>
>
>
>>> If anyone is interested in the equivalent functionality using an
>>> ATTiny25 (for instance, if you’re already heavily invested in AVR instead
>>> of PIC, like I am), ping me. I’ve privately written code to solve almost
>>> the same problem and it could easily be adapted into doing the same job.
>>>
>>>
>
> Is there an easy circuit to build that can consistently deliver a 1
> PPS from a 10MHz source with excellent resolution and repeatability?  My
> first application is to test different 10MHz oscillators without a TIC
> always attached and then compare the PPS output change over time against a
> master GPSDO PPS with an HP53132A.
>
> The circuit used for PPS generation would have to deliver consistent
> PPS output with preferably not more than 100ps noise or jitter, assuming a
> perfect source.  I'm totally guessing that for this resolution, the PPS
> would have to be generated and accurate to within 0.001Hz every second.  
> If
> this is too difficult, maybe the integration time can be increased to
> generate one pulse every 10second or every 100,000,000.00 cycles?
>

>
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Re: [time-nuts] Timelab, two SR620s and losing samples

[Adrian Godwin]

If you have RS232 connections, won't you have one for each device ? Whereas
with GPIB, you'll (probably) only have one bus. The GPIB bus will arbitrate
and avoid both instruments talking at the same time (this might not be true
in talk-only mode since there's no target address involved) but it doesn't
provide two completely separate channels.


On Sun, Jan 17, 2016 at 1:01 PM, Magnus Danielson <
mag...@rubidium.dyndns.org> wrote:

> Poul-Henning,
>
> On 01/17/2016 01:45 PM, Poul-Henning Kamp wrote:
>
>> 
>> In message <569b8b2e.5070...@rubidium.dyndns.org>, Magnus Danielson
>> writes:
>>
>> I think you should develop that line of thought, to detail why it helps
> on GPIB and why not on serial.
>

 It's really very simple:  RS-232 sends blind, you don't even need to
 know if there is a receiver or what it does.  If the receiver cannot
 keep op, data is simply lost.

 GPIB handshakes every byte, so the actions of the receiving end affects
 the transmitting end - in particular if the receiver cannot keep up.

>>>
>>> OK, you where thinking about the flow-control.
>>>
>>> You can have RS-232 wired up to do flow-control (hardware-flow-control),
>>>
>>
>> But the important point is you don't have to do that, all you need
>> is two wires:  GND-GND and TXD->RXD
>>
>> With GPIB that option does not exist, sender and receiver are always
>> in lock-step.
>>
>> Therefore, talk-only mode is a big advantage in terms of decoupling
>> on RS-232 and makes almost no difference on GPIB.
>>
>>
> If we can assume the consumption is fast enough to keep track, yes.
> If it's not, flow control for this situation helps the border case
> somewhat, but if you are too slow, you are screwed anyway.
>
> In the case that Attila describes, the flow-control helps over the various
> borders, especially as scheduling plays tricks with us. Running virtual
> applications like that does not help to get a grip of control over how data
> is transfered and when. If it where only to get it straight into an app
> really talking to the serial ports, sure, but I do not trust the
> virtualization to handle it all to well.
>
> Not that hardware flow-control would in itself help much, but anyway.
>
> Regardless, if the TimeLab needs to send commands back to the counter over
> the virtualization border, then getting things scheduled properly in time
> isn't really guaranteed.
>
> Cheers,
> Magnus
>
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Re: [time-nuts] Generating a solid PPS from 10Mhz source

[Adrian Godwin]

You might have come across the Raspberry Pi story : one of the revised
versions had a SMPS control chip that was intended to be buried inside a
phone, not exposed on an open pcb.

https://www.raspberrypi.org/forums/viewtopic.php?t=99042


On Mon, Jan 18, 2016 at 3:11 PM, Bob Camp  wrote:

> Hi
>
> Back in the 70’s I was involved in making LCD watches. The whole “photo”
> issue had not been fully through through. One day our chief marketing guy
> for
> the project was driving around in Phoenix AZ. He looks down and notices
> that
> his watch is dead. Pops out a spare, puts it on, confirms it it working.
> Hangs his arm out
> the window and …. that one is dead as well.
>
> We changed the die coat on the ASIC to an opaque version soon after that …
>
> Light does indeed interact with semiconductors. It happens even on
> circuits that
> you would not *think* are photo sensitive. Physics is nasty that way ….
>
> Bob
>
> > On Jan 18, 2016, at 6:45 AM, Poul-Henning Kamp 
> wrote:
> >
> > 
> > In message <569bc23a.3030...@arcor.de>, Gerhard Hoffmann writes:
> >
> >> LEDs abused as References:
> >
> > This is one of the most stupid ideas ever, because LEDs works both ways.
> >
> > (Back when LED wrist-watches first came out, people soon discovered
> > that they would reset themselves when photographed with flash.)
> >
> > If you insist on using LEDs as voltage references, the first thing
> > you need to do is to dip the LED in something which shields it 100%
> > from incoming light *including infrared*
> >
> > --
> > Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
> > p...@freebsd.org | TCP/IP since RFC 956
> > FreeBSD committer   | BSD since 4.3-tahoe
> > Never attribute to malice what can adequately be explained by
> incompetence.
> > ___
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> > To unsubscribe, go to
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Re: [time-nuts] HP Z3801A Internal Power Supply issues

[Adrian Godwin]

A tant melted on one of my KS-246361 boxes (I guess they're a similar age,
possibly even the same source). The only one so far to have trouble. It
failed in such a way that it continued to smoke and load up the power
supply,

The current drawn from the no-name laptop power supply was still well
within spec, at least by the time I post-mortem'ed it. But that melted too,
and took out three levels of circuit breakers. The KS-24361 worked
perfectly after replacing the cap.




On Sun, Jan 31, 2016 at 4:42 PM, Bob Camp  wrote:

> Hi
>
> I had one that took out the internal fuse once every 3 to 5 years. After
> replacing the fuse 3 times, the supply died. Go figure … only 15 years or
> use.
>
> Bob
> > On Jan 31, 2016, at 9:11 AM, paul swed  wrote:
> >
> > As I mentioned in the another thread this week.
> > You can indeed replace the failed voltage with just another inverter.
> > Mine has run this way for 10 years. Mine was a 5 by the way. If it was
> one
> > side of the +/-15 I would say you want to replace both.
> > The entire switcher can be replaced with supplies that work off of 110 so
> > you can get rid of the 48 volt supplies.
> > Good luck
> > Paul
> > WB8TSL
> >
> > On Sun, Jan 31, 2016 at 12:04 AM, Alex Pummer  wrote:
> >
> >> power supply runs for a while, output current increases, but voltage
> stays
> >> correct -> problem is in the load circuit, load circuit working for a
> while
> >> load current increases, but it recovers after pause -> look for some
> >> tantalum capacitor in the load circuit, they recover often  a few times
> >> before they finally die,
> >> KJ6UHN
> >> Alex
> >>
> >> On 1/30/2016 6:21 PM, Artek Manuals wrote:
> >>
> >>> My Z3801A began to die over the last few days. It would work for an
> hour
> >>> or two then produce a receiver error and communications problems. Turn
> it
> >>> off, let it sit awhile, back on and it would start the survey and then
> >>> begin to recover. Tonight it finally went dead with high current on the
> >>> main input . The feed supply has a 2amp current limit so I have not
> blown
> >>> the two 3amp fuses
> >>>
> >>> I have a schematic of the supply reverse engineered by Stefan
> Hegnauere a
> >>> few years ago (thank you very much) and a limited theory of operation
> >>> description so I am not totally dead from a troubleshooting point of
> view
> >>> although if one of the DC-DC converters is dead then I will likely
> have to
> >>> scrap the supply
> >>>
> >>> Questions
> >>> 1) Any prior experience as where to look first I checked the
> >>> electrolytics and at first glance they seem fine, no loss of magic
> smoke or
> >>> any parts obviously hot or bulging. ESR 's look good on those
> >>> 2) Will this supply function unloaded while I troubleshoot it on the
> >>> bench out of the unit?
> >>> 3) Anyone tried independent powering the Z3801? looks like two 5V
> >>> supplies and +/- 15V..not hard to to do
> >>> 4) Anyone with a good supply from a parts unit want to part with same?
> >>>
> >>> Dave
> >>> NR1DX
> >>> ArtekManuals.com
> >>>
> >>>
> >> ___
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Re: [time-nuts] HP Reliability

[Adrian Godwin]

HP built their reputation for quality and reliability with test equipment.
Computers were always considered a bit weird (in a nice way, in the case of
handheld calculators) but printers have followed the consumer race to the
bottom.

It's sad to hear that the instrument division are no longer focused on
keeping that reputation - perhaps that's why the medical division moved to
separate the names.

On Sun, Feb 14, 2016 at 11:28 AM, Dr. David Kirkby (Kirkby Microwave Ltd) <
drkir...@kirkbymicrowave.co.uk> wrote:

>On 14 Feb 2016 09:04, "Perry Sandeen via time-nuts"  >
> wrote:
> >
> > Hi,
> > It is rather depressing to me to hear RK and others remark about the
> unreliability of HP test equipment.
> > There is one area where they had outstanding equipment.
>
> I have a friend with a fairly large lab. He must have 50 signal generators,
> 15 spectrum analyzers, plus plenty of other stuff. Mainly RF. Most is
> HP/Agilent, but he has Rohde & Scwarz and Anritsu too. He finds the HP the
> most reliable.
>
> Also Anritsu seem to charge a lot for calibration.  A recent repair to a
> modern 6 GHz Anritsu signal generator resulted in the repair bill plus
> £1200 GBP (around $1800) for calibration. That particular sig gen, which
> was sold for mobile phone use, has an electronic attenuator that will blow
> up if a mobile phone is transmitted into it.
>
> He used to think he preferred R&S signal generators to Agilent,  but the
> reliability of the R&S has been poorer so his mind has been changed on
> that.
>
> I am sure every company has some products that have been very reliable and
> some less so, but I would dispute that HP is in general less reliable than
> other decent makes.
>
> Support on HP is generally good, with the forums which are answered by
> Keysight staff. (An annoying exception seems to be LCR meters and Impedance
> analyzers developed in Japan. The Japanese engineers hardly ever visit the
> forums so questions on LCR meters and impedance analyzers generally get no
> response.)
>
> There are instrument ranges where other manufacturers seem better (e.g.
> Keithley for electrometers), but overall HP/Agilent seem the best choice to
> me.
>
> I know someone who is looking for a 20.GHz VNA. He just lost out on a
> Windows based R&S VNA that sold on eBay for a bit over $7000. There's no
> way a 20 GHz Windows based Agilent VNA would fetch so little.  This is
> reflected in their higher resale values.
>
> At least with the older stuff,, service manuals for HP are useful,  though
> modern service manuals are less so.
>
> Just my opinion.
>
> Dave.
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Re: [time-nuts] MTI 260-0624-D OCXO

[Adrian Godwin]

I have a small collection of 10811 and similar oscillators here, collected
from hamfests rather than china (and mostly pre-ebay).

What sort of testing regime would you put them through ? I don't have
anything as exotic as a timepod but I do have an HP53131A, the Tait Rb
source, and a KS-24361 set up. And always keen to get hints on the
acquisition of new toys !



On Thu, Feb 18, 2016 at 12:09 PM, Bob Camp  wrote:

> Hi
>
> It is *much* better to have an OCXO that you do not need to test to death.
> There is simply to much testing to do. A modern factory does not test the
> quality into the product (of any sort) they design in and build it in. The
> same
> is true of the normal customer for virtually any component. They make sure
> the parts come from somebody they can trust and save a lot of testing time.
>
> That said, yes, I have a pile of scrap parts sitting in front of me as I
> type this.
> It’s a hobby. Time does not count. It lets me play with all sorts of toys
> doing
> the testing. I occasionally learn things in the process. Mostly I learn
> that
> my hope of a 100% perfect batch is still a dream ….
>
> Bob
>
>
>
> > On Feb 17, 2016, at 9:56 PM, time...@metachaos.net wrote:
> >
> > Bob,
> >
> > In this case, I know how it was taken off the board - it wasn't. They
> just cut
> > the board around it. I had to remove it myself. Nice thing about that,
> is that
> > I got a nice plastic, pre-formed part that fits between the board and the
> > OCXO, probably as an insulator.
> >
> > You are also right about the number of things that you need to test to
> make
> > sure that one of these is fully functional. However, this is a "starter"
> OCXO
> > for me and I don't yet have the equipment to perform the tests. The best
> that
> > I can do is to make sure that, when powered up
> >
> >   1. I see something that sort of looks like a sine wave at a reasonable
> >  magnitude.
> >
> >   2. My 2465B CT frequency counter thinks that it is somewhere near 5Mhz.
> >
> >   3. If I apply gnd, or VRef to the adjustment pin I see the frequency
> change
> >  at least a small amount.
> >
> > Without more equipment, there isn't much more that I can do to test.
> Unless
> > you have some suggestions?
> >
> >
> > Mike
> >
> >
> >> Hi
> >
> >> Best guess is these things get taken off the board with either a big
> torch or a charcoal fire.
> >> You can ask Mr Google to dig up pictures of the process. Depending on
> just how quick
> >> they are, the insides of the OCXO can easily be reflowed. The
> likelihood of it reflowing and
> >> cooling back to a reliable joint … not real good.
> >
> >> Bob
> >
> >>> On Feb 17, 2016, at 5:16 AM, Andrea Baldoni 
> wrote:
> >>>
> >>> On Tue, Feb 16, 2016 at 07:58:21PM -0500, time...@metachaos.net wrote:
> >>>
>  I just received a 5Mhz OCXO from eBay (MTI 260-0624-D OCXO). After
> testing it,
>  it is clear that it is defective.
> 
>   1. It never heats up.
>   2. The reference voltage is zero.
>   3. Only noise is seen on the output pin.
> >>>
> >>> I had the same issue with some of them. It's very likely that the
> internal
> >>> solder connections from pins to PCB are broken, at least, the one for
> power.
> >>> It happens because the inner oven is heavy and there isn't any thermal
> >>> insulator (besides air) to keep it from moving.
> >>>
> >>> Wheter the crystal has been damaged or not, it's unknown. I had one
> where the
> >>> crystal actually fell off from its supports too.
> >>>
> >>> I posted a link to photos of the internals, time ago. The link is dead
> now
> >>> and I don't think to have the photos anymore but perhaps someone
> downloaded
> >>> them.
> >>>
> >>> Best regards,
> >>> Andrea Baldoni
> >>> ___
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> >
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> >
> >
> >
> > --
> > Best regards,
> > Timenutmailto:time...@metachaos.net
> >
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Re: [time-nuts] Inside a CTS 1960017 OCXO

[Adrian Godwin]

Could it be microphonic capacitors, or the crystal itself ?
Have you got a big old heavy power supply with a buzzing transformer on
your workbench ?


On Sun, Feb 28, 2016 at 3:04 PM, Daniel Watson 
wrote:

> Hi,
>
> I put one in a freezer and measured the current draw. At -12*C, it drew
> about 320 mA steady state (1.6W).
>
> Dan
>
> On Sat, Feb 27, 2016 at 7:30 PM, Rob Sherwood.  wrote:
>
> > The part draws 600 mA during warm-up, and drops to around 230 to 200 mA
> > when stabilized.
> > Rob
> > NC0B
> >
> > -Original Message-
> > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob
> Camp
> > Sent: Saturday, February 27, 2016 2:26 PM
> > To: Discussion of precise time and frequency measurement
> > Subject: Re: [time-nuts] Inside a CTS 1960017 OCXO
> >
> >
> >
> > Hi
> >
> > A small air gap is actually a better insulator than conventional foam.
> You
> > don’t get much of a convection cell going at those spacings. The part
> > likely pulls a bit over a watt at room.
> >
> > If you put an insulator on the gizmo you increase it’s thermal gain. That
> > will most likely make the temperature performance significantly worse.
> See
> > the good old papers on the HP super ovens for all the details.
> >
> > Bob
> >
> > > On Feb 27, 2016, at 12:44 PM, Tom Miller 
> > wrote:
> > >
> > >
> > > - Original Message - From: "Daniel Watson"
> > > 
> > > To: 
> > > Sent: Saturday, February 27, 2016 11:48 AM
> > > Subject: [time-nuts] Inside a CTS 1960017 OCXO
> > >
> > >
> > >> Hi,
> > >>
> > >> I'm sure many of you are tracking the cheap CTS 10MHz OCXOs available
> > >> on eBay right now. I purchased a case of them, and decided to crack
> one
> > open.
> > >> I took pictures along the way, thinking that might be interesting to
> > >> the list. Here is the blog post if you are interested:
> > >>
> > >> http://syncchannel.blogspot.com/2016/02/10mhz-ocxo-teardown-cts-19600
> > >> 17.html
> > >>
> > >> Comments on the internal construction of the OCXO are welcome. It
> > >> seems pretty straightforward inside though.
> > >>
> > >>
> > >> Best regards,
> > >>
> > >> Dan W.
> > >
> > > Looks like it would use a lot of power in a cold environment. Maybe a
> > second oven would be nice. They seem to have marked the turnover temp on
> > the xtal.
> > >
> > > Regards
> > > ___
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> >
> >
> >
> > --
> > If this email is spam, report it to
> >
> >
> https://support.onlymyemail.com/view/report_spam/ODExMjI6MTg1NzM5Mjc1MDpyb2JAbmMwYi5jb206ZGVsaXZlcmVk
> >
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Re: [time-nuts] Lady Heather Server On Raspberry Pi 2 Model B?

[Adrian Godwin]

This turned out to be an easy way to run Lady Heather itself (herself ?) on
Linux - it works well under Wine, but identifying the serial port is a
problem. But run Heather with '/ip=localhost' and ser2net to connect to the
USB serial port and all is smooth.

I used the ser2net config line

45000:raw:0:/dev/serial/by-id/usb-Generic_USB_to_Serial_Converter_OCB6T5Y1-if00-port0:9600
8DATABITS ODD 1STOPBIT LOCAL

to identify a specific ftdi converter connected to a Trimble Resolution T
rather than a thunderbolt (it requires 8 / odd / 1)






On Tue, Jan 12, 2016 at 2:40 PM, Mike George  wrote:

> Ed:
>
> A few recommendations for troubleshooting.
>
> In /etc/ser2net.conf comment out the 4 default lines (/dev/ttyS0-3)
> so that the line Nick provided is the only config present.
>
> Stop ser2net:
>  /etc/init.d/ser2net stop
> then restart:
>  /etc/init.d/ser2net start
>
> Make sure ser2net is running:
>  ps -ef | grep ser2net
>
> If not, tail /var/log/syslog and see if any errors were reported on
> statrtup.
> Normally you just see a single line reporting successful startup.
>
> If it is running , make sure it is listening on the socket you specified
> (3200):
>netstat -tln | grep 3200
>
> you should see a line with 0.0.0.0:3200 under local address
>
> There is additional troubleshooting you can do depending on results
> of above steps.
>
> Good luck.
>
> Mike
>
> On 1/12/2016 03:58, Ed Armstrong wrote:
>
>> More details please. I've installed it, but can't make it work. My
>> USB/serial cable is /dev/ttyUSB0 just like yours. I used your .conf file.
>> But lady heather says connection rejected.
>>
>>
>> Ed
>>
>> On 1/11/2016 8:00 PM, Nick Sayer via time-nuts wrote:
>>
>>> I answered my own question. :)
>>>
>>> ser2net works perfectly as a “server” for LH. I’m using a USB to serial
>>> adapter and the ser2net.conf line for it is
>>>
>>> 3200:raw:0:/dev/ttyUSB0:9600 8DATABITS NONE 1STOPBIT LOCAL
>>>
>>> And for LH, /ip=n.n.n.n:3200 works.
>>>
>>> _
>>> time-nuts mailing list -- time-nuts@febo.com
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>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>>
>>>
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Re: [time-nuts] Conditioning Rubidium Oscillators

[Adrian Godwin]

My understanding of the article was that although fairly simple control
techniques such as PID were used, their innovation was to determine what
function the loop was performing, (initial lock, stability, and transition
from one to the other) and to choose a set of constants for loop control
appropriate to each type. The ideal loop characteristics are not the same
for all of these.


On Tue, Mar 15, 2016 at 7:51 PM, Attila Kinali  wrote:

> On Mon, 14 Mar 2016 19:56:42 -0400
> Jim Harman  wrote:
>
>
> Disclaimer: Control theory is not my strongest topic. I am pretty sure
> that what I have written here is correct. But if anyone finds any
> mistakes, please correct me.
>
> > On Mon, Mar 14, 2016 at 2:37 PM, Lars Walenius <
> lars.walen...@hotmail.com>
> > wrote:
> >
> > > I read this but couldn´t understand why this is superior to the PI-loop
> > > with a pre-filter?
> > >
> > >
> > >
> http://ptfinc.com/wp-content/uploads/2016/03/App_37_RubContol-Rubidium-Control-%E2%80%93-A-Different-Approach.pdf
> >
> > > Anybody can say why? Even if regression is very useful the limitation
> of
> > > the GPS and ionosphere will be the problem?How much better is it
> reasonable
> > > to get??
>
> A PID loop adapts to a step as input faster than a PI loop.
> To give a rule of thumb: the D part is used to predict how fast
> the error is moving. If the error is shrinking fast, there will
> be an overshoot once the error reaches zero. Thus the D part is
> used to make the rate of change slower once the error becomes small.
> Nothing more.
>
> The wikipedia entry on PID controllers explains these things in
> some detail and should help understand it.
>
>
> > I think the potential benefit of this approach is that it continuously
> > predicts the long term drift of the oscillator and attempts to compensate
> > for it.
>
> Nope, the above appnote does not predict anything. It's not an adaptive
> control system at all. All they do is describe an PID controller without
> using the common language of the control theory people.
>
> > If the drift is reasonably linear, this means that you can use a
> > larger time constant in the control loop and thus be less sensitive to
> > short term GPS timing variations, while keeping the phase error close to
> > zero
>
> If the drift is linear, then the D part of the PID control loop will
> actually slightly increase the error compared to a PI controller.
>
> Proper adaptive control systems can also model higher order (ie changes
> that have components with a second or third (or higher) derivative) and
> the more fancy stuff even non-linear "drift".
>
> But the math behind that is not easy, and you need to have a good idea
> what the system (including reference, "plant", "sensor" and noise sources)
> looks like to build a control loop that improves on the PID controller.
> It's also quite easy to botch it up and make something that performes worse
> than just a P controller
>
> > Of course if the oscillator drift is not predictable, this won't help and
> > might even make things worse.
>
> A lot of the components of the drift of most oscillators is actually
> quite predicatble. If you take a Rb vapor reference, the largest three
> drift components will be aging of the cell, temperature and air pressure.
> All three of them are relatively easy to model and can remove a lot
> of uncertainty (how much can be removed depends highly on the make up
> of the physics package).
>
> > I have done some experiments with an OCXO and a controller design similar
> > to the one Lars posted some time ago. I plotted the trend in the 3-hour
> > average DAC values over many days and used Excel to do a least-squares
> fit
> > to that data. As long as the oscillator is powered on continuously, this
> > gives an R^2 of over 90%, so the linearity of the drift is very good. If
> I
> > use this slope as a correction factor, i.e. adding X DAC counts per day
> to
> > the output of the PI control algorithm, it significantly reduces the
> > average TIC error at long time constants
>
> You could use a simple, single variable Kalman filter control loop to
> improve your PI controller. Just assume linear aging and let the
> Kalman filter predict it. For a gentle introduction into Kalman filters
> have a look at [1]. And yes this of course reduces the average TIC error,
> as you are removing one of the systematics, which has a relatively high
> contribution to the TIC error. The better the model of the system you
> are using and thus the more systematics you compensate for, the smaller
> the error will become and the more it will look like uncorrelated noise.
> But as I have written above, once you start doing more complex models,
> it gets harder to actually improve the output instead of detoriating it.
> If you make a mistake in the model, it will predict the wrong thing
> and thus correct into the wrong direction. And more often than not
> the detoriation will be larger than what the total gain of a simpler
> model would

[time-nuts] KS-24361 rom

[Adrian Godwin]

I've dumped out the KS24361 ROM using the built-in Forth interpreter as a
move towards reverse-engineering it.

Is there somewhere I can put this for easy access ? I imagine it's
copyright HP and although I doubt they'll care, I don't want to cause any
problems.

-adrian
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Re: [time-nuts] KS-24361 rom

[Adrian Godwin]

Thanks, Tom - that sounds like a rather exclusive club !

I'm afraid my pForth is nothing to be proud of - I've forgotten most of it
and had to look practically everything up. But it did the job.


I've uploaded it as KS24361-Z3812A-KR92830585-X98_4-A.zip


On Sat, Apr 16, 2016 at 11:36 AM, Tom Van Baak  wrote:

> Adrian,
>
> Thanks for doing that. And you're now a member of the hp Smartclock pForth
> appreciation club ;-)
>
> You can send the ROM to me or Magnus, or better yet post it under "01 ROM
> Images and Drivers" at Didier's site:
>
> http://www.ko4bb.com/manuals/
>
> /tvb
>
>
> - Original Message -
> From: "Adrian Godwin" 
> To: "Discussion of precise time and frequency measurement" <
> time-nuts@febo.com>
> Sent: Friday, April 15, 2016 1:56 PM
> Subject: [time-nuts] KS-24361 rom
>
>
> > I've dumped out the KS24361 ROM using the built-in Forth interpreter as a
> > move towards reverse-engineering it.
> >
> > Is there somewhere I can put this for easy access ? I imagine it's
> > copyright HP and although I doubt they'll care, I don't want to cause any
> > problems.
> >
> > -adrian
> > ___
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Re: [time-nuts] help

[Adrian Godwin]

They're a LED and some current limiting. Some are specced as low as 3V and
10mA but they're optimised for 12-24. I'd definitely use a transistor and
at least 5V, especially from something like a Pi or Teensy, which have 3v3
logic levels.

My reading is that Bill doesn't want to mess around with micros and
electronics, though. He wants an off-the-shelf timeswitch that - for
perfectly understandable reasons of engineering pedantry - is always
correct.

On Mon, May 2, 2016 at 5:56 PM, jimlux  wrote:

> On 5/2/16 8:24 AM, Nick Sayer via time-nuts wrote:
>
>> To flesh this out a bit more, on a Raspberry Pi, it would be easy to make
>> a cron job that would pulse a GPIO pin high. They really *want* you to use
>> Python (thus the name), but this is easy to do in just a shell script.
>> First, do this to set things up:
>>
>> #! /bin/sh
>>
>> GPIO_PIN=9 # pick whatever one you like
>>
>> echo $GPIO_PIN > /sys/class/gpio/export
>> echo out > /sys/class/gpio/gpio${GPIO_PIN}/direction
>> echo 0 > /sys/class/gpio/gpio${GPIO_PIN}/value
>>
>> Next, run this script out of cron:
>>
>> #! /bin/sh
>>
>> GPIO_PIN=9
>> echo 1 > /sys/class/gpio/gpio${GPIO_PIN}/value
>> sleep 1
>> echo 0 > /sys/class/gpio/gpio${GPIO_PIN}/value
>>
>> That will make a positive going pulse with the leading edge synchronized
>> to cron (for sufficiently vague definitions of “synchronized”).
>>
>> As for the hardware side, take the GPIO pin and connect a 10k resistor
>> between it and the base of a 2N4401 transistor. Connect the emitter to
>> ground and the collector is a classic “open collector” switching output.
>> Think of it like a switch connection to ground. When it’s on, there is a
>> low impedance path to ground. When it’s off, it’s high impedance. You can
>> use it to work a relay (be sure to add a flyback diode across the relay
>> coil) or directly to switch any load that doesn’t exceed the abilities of
>> the transistor.
>>
>> If you want to be a little safer, you can use an opto-isolator instead.
>> Connect the GPIO pin to a 150 Ω resistor and then to the anode of the LED
>> in an optoisolator. Connect the cathode to ground. The optoisolator itself
>> can be either a phototransistor type or a driver triac type (the latter
>> would be used to drive a power triac to switch AC loads on and off).
>>
>>
>>
>
> SSR data sheet at mouser (they are <$20)
> http://www.mouser.com/ds/2/307/g3na_ds_e_11_1_csm165-892371.pdf
>
> myriad varieties of inputs and outputs, whether it has an indicator (nice
> for testing), whether it's a zero voltage switch.
>
> BUT.. it kind of looks like it wants to see 4V to turn on for sure. Maybe
> your 5V USB powered widget puts out that on a GPIO pin, maybe it doesn't.
> I've had very mixed luck with driving SSRs directly from logic (because the
> real threshold voltage and the real logic output voltage vary with
> temperature, for instance).
>
> I'd use the extra transistor as an open collector and a 12V wall wart or
> similar to provide the current for the SSR input.
>
>
>
>
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Re: [time-nuts] help

[Adrian Godwin]

Here's a possible solution. It's ethernet-connected and will switch a 10A
output. It's made for UK use but would probably be fine if you have a 220V
supply. It doesn't say whether it tracks NTP, but looking at the specs i'd
suggest it's linux inside and can do that.

http://www.audon.co.uk/webcontrol/EZ-21g.html


On Mon, May 2, 2016 at 7:21 PM, Adrian Godwin  wrote:

> They're a LED and some current limiting. Some are specced as low as 3V and
> 10mA but they're optimised for 12-24. I'd definitely use a transistor and
> at least 5V, especially from something like a Pi or Teensy, which have 3v3
> logic levels.
>
> My reading is that Bill doesn't want to mess around with micros and
> electronics, though. He wants an off-the-shelf timeswitch that - for
> perfectly understandable reasons of engineering pedantry - is always
> correct.
>
> On Mon, May 2, 2016 at 5:56 PM, jimlux  wrote:
>
>> On 5/2/16 8:24 AM, Nick Sayer via time-nuts wrote:
>>
>>> To flesh this out a bit more, on a Raspberry Pi, it would be easy to
>>> make a cron job that would pulse a GPIO pin high. They really *want* you to
>>> use Python (thus the name), but this is easy to do in just a shell script.
>>> First, do this to set things up:
>>>
>>> #! /bin/sh
>>>
>>> GPIO_PIN=9 # pick whatever one you like
>>>
>>> echo $GPIO_PIN > /sys/class/gpio/export
>>> echo out > /sys/class/gpio/gpio${GPIO_PIN}/direction
>>> echo 0 > /sys/class/gpio/gpio${GPIO_PIN}/value
>>>
>>> Next, run this script out of cron:
>>>
>>> #! /bin/sh
>>>
>>> GPIO_PIN=9
>>> echo 1 > /sys/class/gpio/gpio${GPIO_PIN}/value
>>> sleep 1
>>> echo 0 > /sys/class/gpio/gpio${GPIO_PIN}/value
>>>
>>> That will make a positive going pulse with the leading edge synchronized
>>> to cron (for sufficiently vague definitions of “synchronized”).
>>>
>>> As for the hardware side, take the GPIO pin and connect a 10k resistor
>>> between it and the base of a 2N4401 transistor. Connect the emitter to
>>> ground and the collector is a classic “open collector” switching output.
>>> Think of it like a switch connection to ground. When it’s on, there is a
>>> low impedance path to ground. When it’s off, it’s high impedance. You can
>>> use it to work a relay (be sure to add a flyback diode across the relay
>>> coil) or directly to switch any load that doesn’t exceed the abilities of
>>> the transistor.
>>>
>>> If you want to be a little safer, you can use an opto-isolator instead.
>>> Connect the GPIO pin to a 150 Ω resistor and then to the anode of the LED
>>> in an optoisolator. Connect the cathode to ground. The optoisolator itself
>>> can be either a phototransistor type or a driver triac type (the latter
>>> would be used to drive a power triac to switch AC loads on and off).
>>>
>>>
>>>
>>
>> SSR data sheet at mouser (they are <$20)
>> http://www.mouser.com/ds/2/307/g3na_ds_e_11_1_csm165-892371.pdf
>>
>> myriad varieties of inputs and outputs, whether it has an indicator (nice
>> for testing), whether it's a zero voltage switch.
>>
>> BUT.. it kind of looks like it wants to see 4V to turn on for sure. Maybe
>> your 5V USB powered widget puts out that on a GPIO pin, maybe it doesn't.
>> I've had very mixed luck with driving SSRs directly from logic (because the
>> real threshold voltage and the real logic output voltage vary with
>> temperature, for instance).
>>
>> I'd use the extra transistor as an open collector and a 12V wall wart or
>> similar to provide the current for the SSR input.
>>
>>
>>
>>
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>> and follow the instructions there.
>>
>
>
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Re: [time-nuts] help

[Adrian Godwin]

Since you have an impulse clock system, you could use that to fire the bell
- you could modify a slave clock or use one of these :

http://www.ebay.co.uk/itm/111982558390

or possibly this one :

http://www.ebay.co.uk/itm/291730808914

The first seems rather expensive to me, I've more commonly seen them at
more like the second price. You can probably find one nearer to you.

You still then have the problem that you want to drive the impulse from an
accurate time source. There are impulse drivers that operate from a cheap
crystal available on ebay. I don't think we want to talk about those here.

A nicer solution would be to transform the 1pps signal from a gps receiver
into a suitable pulse : again, this is easy to do with a microcontroller
and a small amount of electronics, but it seems like a useful idea. Perhaps
worth working out properly and publishing.

I have in the past run a slave clock from an RS232 port : it needs a small
circuit to generate the current pulse (powered by the RS232 port itself)
and operated by a small script program on a computer, so locked to NTP.
However, it needs a computer (preferably Unix) running 24/7.




On Mon, May 2, 2016 at 7:11 PM, Mark Sims  wrote:

> If you want to get fancy you could modify Lady Heather to do the deed.
> Heather has a "singing clock" mode and a cuckoo/chime clock mode for
> playing sound files at various times.  It also has routines for controlling
> the serial port DTR and RTS lines (currently used for PWMing a fan if
> temperature control mode is enabled).   You could add some code to the
> program to pulse the DTR or RTS line... these can easily drive a solid
> state relay.
>
>
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Re: [time-nuts] What is "accuracy"? (newbie timenut, hi folks!)

[Adrian Godwin]

With regard to the data sheet, all the specified errors have to be added to
get the worst case (though they may not all operate in the same direction).

So you have the initial accuracy at delivery, + a term related to age, + a
term related to temperature and any other factors that are specified. These
may add in various wys, but shouldn't exceed the worst possible combination
of all acting in the same direction.



On Fri, May 6, 2016 at 5:22 AM, wb6bnq  wrote:

> Hello Belinda,
>
> First off there is no such thing as accuracy, in and of itself.  I know
> many people on this list will call me on that, but accuracy requires a
> point of reference.  With regard to frequency that reference point has been
> defined by some World committee as a certain number of oscillations in a
> Cesium atom controlled within a specific set of conditions.
>
> The 100 ppm statement is talking about a change in frequency due to
> temperature,  The typical 100 ppm statement is saying for every change of 1
> degree (usually "C") the oscillator (or other components such as resistors,
> capacitors, etc.) will shift in value by a worst case of 100 ppm (parts per
> million).  This has nothing to do with accuracy except that it would not be
> considered accurate relative to a reference point.  What it does address is
> specifically the stability, but is not the only condition affecting
> stability.
>
> With respect to accuracy and stability, they are not related.  That is to
> say you could have extreme stability (say parts in 10 to the minus 21) and
> it could be way off from the recognized standard reference.  In the other
> direction you could have something that is adjusted to be precisely in
> agreement with the reference standard but will only hold that value for a
> very brief period of time.  The first case is a very good (and quite
> expensive) oscillator and the second example is a poor (and not expensive)
> oscillator.
>
> With regard to precision, the best example would be shooting at a target
> and how tight the grouping is maintained.  The tighter the grouping the
> better the precision.  You could have a tightly well defined small group of
> holes from the bullets but they could be anywhere on the paper target.  The
> only time you have accuracy (with respect to the shooting) is if all the
> bullets were directly in the bulls eye (center of target).  And if you can
> consisterntly repeat hitting just the bulls eye then you have stability.
>
> BillWB6BNQ
>
>
> BJ wrote:
>
> Hi Time Nuts,
>>
>>
>>
>> I'm fairly new to the fascinating world of time and frequency, so I
>> apologise profusely in advance for my blatant ignorance.
>>
>>
>>
>> When I ask "what is accuracy" (in relation to oscillators), I am not
>> asking
>> for the textbook definition - I have already done extensive reading on
>> accuracy, stability and precision and I think I understand the basics
>> fairly
>> well - although, after you read the rest of this, you may well (rightly)
>> think  I am deluding myself. It doesn't help matters when some textbooks,
>> papers and web articles use the words precision, accuracy and uncertainty
>> interchangeably. (Incidentally, examples of my light reading include the
>> 'Vig tutorial' on oscillators, HP's Science of Timekeeping Application
>> note,
>> various NIST documents including the tutorial introduction on frequency
>> standards and clocks, Michael Lombardi's chapter on Time and Frequency in
>> the Mechatronics Handbook and many other documents including PTTI and
>> other
>> conference proceedings). Anyway, you can safely assume I understand the
>> difference between accuracy and precision in the confused musings that
>> follow below.
>>
>>
>>
>> What I am trying to understand is, what does it REALLY mean when the
>> manufacturer's specs for a frequency standard or 'clock' claim a certain
>> accuracy. For ease and argument's sake let us assume that the accuracy is
>> given as 100 ppm or 1e-4 
>> As per the textbook approach, I know I can therefore expect my 'clock' to
>> have an error of up to 86400x1e-4= 8.64 s per day.
>>
>>
>>
>> But does that mean that, say, after one day I can be certain that my clock
>> will be fast/slow by no more than 8.64 seconds or could it potentially be
>> greater than that? In other words, is the accuracy a hard limit or is it a
>> statistical quantity (so that there is a high probability that my clock
>> will
>> function this way, but that there is still a very small chance (say in the
>> 3sigma range) that the error may be greater so that the clock may be
>> fast/slow by, say, 10 seconds)? Is it something inherent, due to the
>> nature
>> of the type of oscillator (e.g. a characteristic of the crystal or atom,
>> etc.) or does it vary so that it needs to be measured, and if so, how is
>> that measurement made to produce the accuracy figure? Are environmental
>> conditions taken into account when making these measurements (I am
>> assuming
>> so)? In other words, how is the 

[time-nuts] NPL open day

[Adrian Godwin]

In case anyone's in London this week, the NPL have an open day :

http://www.npl.co.uk/openhouse/
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Re: [time-nuts] OT stuffing boards: was GPS interface/prototyping board

[Adrian Godwin]

On Fri, Jun 24, 2016 at 3:32 PM, Attila Kinali  wrote:

>
> The trick is to use semi-manual pick&place machines for low volumes.
> Ie machines that you do not program, but guide by hand. This allows
> faster and more accurate placing of components than would be possible
> with a pure manual process, but does not have any of the complexity
> of the fully automated solutions. The components do not need to be
> 100% exactly centered, as the surface tension of the molten solder will
> pull the parts into place (which is also the reason why the copper inside
> the solder resist mask should be symmetric).
>

For what it's worth, I have a manual / guided pick and place machine
available. UK pickup only unless you're really keen ! Off-list please if
anyone's interested.

-adrian
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Re: [time-nuts] pick and place problems/design (was: OT stuffing boards)

[Adrian Godwin]

Many parts can't be recognised visually. Capacitors are the obvious example.

On Sat, Jun 25, 2016 at 6:11 AM, Chris Albertson 
wrote:

> The ideal hobby use pick and place machine would be very different
> from a commercial machine.  Lets say I want one board made.   What I
> want to minimize is my time.  With a conventional machine by FAR most
> of my time is spent setting the machine up.  In fact setup is so slow
> that for smaller PCBs I could do it with tweezers in a fifth of the
> time needed to set up the machine.
>
> So a hobby machine must be designed such that you could get it going
> in nearly zero time.   In the ideal case you drop the parts all mixed
> up, (but right side up) in a small tray.  They are mixed and in random
> orientation.  then you give the machine your PCB design file (not a
> special pick and place file) and then a vision system IDs the parts.
> Today vision is dirt cheap.
>
> But the 3D printer needs one more degree of freedom.  It must be able
> to rotate the part (or the PCB) as it is unlikely the part on the tape
> or tray only needs translation to the PCB, likely ration is required
> in almost all cases.
>
> I think a hobby machine would only be successful if it could reduce
> the setup time to nearly zero and for that it would need a really good
> vision system that could hunt down randomly placed parts.  It would
> have to work pretty much like you or I would do the job manually.  But
> we have software like openCV and good "board cams" with M7
> interchangeable lenses for $35.  A vision system actually saves a ton
> of money because the machine need not be so precise as vision closes a
> feedback loop.
>
> Also how many hobbyists are going to have reels of parts?  I might buy
> some parts by the dozen but most no more than about 4 or 6 at a time.
>  I don't want a large machine.  It should have a working surface, a
> white melamine table about 12 inches square and I place the PCB to be
> stuffed and all the parts on the same foot square table at any random
> location then press the "go" button.  The camera scans the table.
> This kind of machine would be horrible for production work but a one
> foot cube machine that required zero setup is what most of us want.
>
> Going a little farther.  I'd like this SAME machine to actually make
> the PCB too.  A 3D printer could route the copper and drill holes and
> print the solder resist plastic too.
>
> On Fri, Jun 24, 2016 at 8:56 PM, Attila Kinali  wrote:
> > On Fri, 24 Jun 2016 13:59:58 -0500
> > "Graham / KE9H"  wrote:
> >
> >> Lots of problems to be solved...
> >
> > Most of these problems are easy:
> >
> >> How do you take loose parts or cut tape or tape reels
> >
> > You don't. No loose parts with any kind of pick&place machine.
> > As for cut tape, these can be taped on an empty reel to make
> > them compatible. Everything has to be in a tray, reel or similar.
> >
> >> and get the right
> >> part out, and into the chuck, oriented in the right direction?
> >
> > Orientation is defined by the reel/tray the parts come in.
> > This is also documented in the datasheet, usually.
> >
> >> How many different kinds of parts, sizes, shapes, pin counts, IC
> >> footprints, can you handle at once?
> >
> > As many as there is space around the machine :-)
> >
> >> How do you know it is the correct part?
> >
> > You put it manually in the right feeder and double check that it
> > fits the programming.
> >
> >> How do you know where the "+" end, or "pin 1" is?
> >
> > This comes with the orientation of the part in the reel/tray.
> >
> >> How do you know that there actually is a part in the chuck?
> >
> > Your trays are guaranteed to be non-empty by manually loading them.
> >
> >> How do you know the part in the chuck is oriented the way you expected
> it?
> >
> > The manufacturer guarantees that the reels/trays are loaded correctly.
> >
> >> How do you know where the footprint on the circuit board is located?
> (to a
> >> few thousandths.)
> >
> > This is provided by the pick&place file. Usually its 3-5 digits after the
> > decimal point, when using mm. But as I wrote before, you don't have to
> > place part hyper exact. Being within 0.1-0.3 of the pitch of the part
> > is usually enough. Surface tension does the rest.
> >
> >> How do you know the part left the chuck and ended up where you intended
> it
> >> to be?
> >
> > You dont :-)
> >
> > The way how this is checked is either a pre-solder and/or post-solder
> visual
> > inspection. This is either done manualy or using a camera system where
> > computer compares the PCB to the picture of a known-good PCB.
> > As this is ment for a small volume and hobbyist system, doing the visual
> > inspection manualy is good enough and more than fast enough.
> >
> > Attila Kinali
> > --
> > Malek's Law:
> > Any simple idea will be worded in the most complicated way.
> > ___
> > time-nuts mailing list -- time-nuts@febo.c

Re: [time-nuts] OT stuffing boards: was GPS interface/prototyping board

[Adrian Godwin]

On Sat, Jun 25, 2016 at 9:26 AM, Steve Wiseman  wrote:

>
> There are mailing lists for this stuff, chaps - openpnp, firepick,
> versatronics, plenty of others. All full of people finding out that,
> like everything, it's trickier than you first think. See you over
> there, let time nuts be time nuts?
>

One such forum is http://electricstuff.co.uk/forum/ . Lots of other good
stuff on Mike's site & youtube stream too.
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Re: [time-nuts] [LEAPSECS] Leap second to be introduced at midnight UTC December 31 this year

[Adrian Godwin]

I was inclined to agree, cynically reasoning that many implementations
would argue that the leapseconds would average out in most applications and
they could ignore them.

But actually, it would be good for programmers to properly separate the
concepts of elapsed time and clock-time. If elapsed time were handled by
kernels and clock-time handled by a user-mode UTC or calendar process, that
would be a cleaner solution with overhead only where needed (or where the
OS is big enough for it to be a trivial element).


As a side issue, what would be the impact of having frequent
leap-milliseconds instead of infrequent leap-seconds ?

On Thu, Jul 21, 2016 at 8:53 PM, Steve Allen  wrote:

> On Thu 2016-07-21T10:27:57 -0700, Tom Van Baak hath writ:
> > Time to mention this again...
>
> > Every UTC-aware device would 1) know how to reliably insert or
> > delete a leap second, because bugs would be found by developers within
> > a month or two, not by end-users years or decades in the future, and
> > 2) every UTC-aware device would have an often tested direct or
> > indirect path to IERS to know what the sign of the leap second will be
> > for the current month.
>
> This idea pushes extra complexity into every implementation of low
> level kernel-space software, firmware, and hardware.  That's nice as a
> policy for full employment of programmers, but it's hard to justify by
> any other metric.  Instead those low level places should be as simple
> as possible, and that means making the underlying precision time
> scale, and thus any broadcast distributions of a precision time scale,
> as simple as possible.
>
> The complexity for translating precision time in seconds (for
> machines) to calendar time in days (for humans) belongs in the
> less-critical and easier-testable outer layers of software which do
> user-space presentation, internationalization, and GUI which can be
> broadly shared between many hardware implementations.
>
> --
> Steve Allen  WGS-84 (GPS)
> UCO/Lick Observatory--ISB 260  Natural Sciences II, Room 165  Lat
> +36.99855
> 1156 High Street   Voice: +1 831 459 3046 Lng
> -122.06015
> Santa Cruz, CA 95064   http://www.ucolick.org/~sla/   Hgt +250 m
> ___
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> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
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Re: [time-nuts] Heathkit clock available

[Adrian Godwin]

On Thu, Aug 11, 2016 at 4:03 AM, Chris Albertson 
wrote:

> Digital clocks are just not the amazing technical wonders they once
> were.
>
>
No, but it's interesting that they've considered the interface rather than
using the common one supported by generic clock chips. Phone interfaces are
rarely good for use in a semi-conscious state, and are inclined to run out
of battery charge.


“Far out in the uncharted backwaters of the unfashionable end of the
western spiral arm of the Galaxy lies a small unregarded yellow sun.
Orbiting this at a distance of roughly ninety-two million miles is an
utterly insignificant little blue green planet whose ape-descended life
forms are so amazingly primitive that they still think digital watches are
a pretty neat idea.”
― Douglas Adams , The
Hitchhiker's Guide to the Galaxy

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Re: [time-nuts] Working with SMT parts.

[Adrian Godwin]

I use a beautiful Wild M3Z that I got at a good price from a British
Aerospace auction. It does have the disadvantage that there's a very exact
spot to place your eyes, but the image is superb. I typically start at the
bottom end (6.5 x 10 x 0.5) but often use the other zoom levels (up to 40 x
10 x 0.5). It has a Volpi fibre optic ring light but LEDs may be a better
solution nowadays.

I also have an illuminated magnifying lamp - I like the ones made by Lux.

I've considered a video microscope for the times when a large screen would
be desirable but computer and tablet ones are said to have a bit of lag
that make precise movements difficult. Direct video without a computer is
probably better.

On Fri, Aug 12, 2016 at 2:14 PM, Bob Camp  wrote:

> Hi
>
> You can get a pretty good microscope new for about $1,000. Getting them
> used is a hit or
> miss process. A lot of this stuff actually works very well when in good
> condition with all the
> parts (The Mantis is one example). Without all the parts they don’t work
> or work poorly.
>
> For most of what you do, there is no need for anything fancy. There is a
> Mantis in full working
> condition at work. It never gets used. Magnifier lights get used a lot.
> Low magnification
> microscopes with really good halogen / fiber optic ring lights seem to be
> the most
> popular option.
>
> Bob
>
>
> > On Aug 11, 2016, at 8:06 PM, Steve  wrote:
> >
> > Can anyone compare the stereo microscope to a camera/monitor for use
> with SMT? I have a cheap stereo microscope that I would like to replace
> with either a much better stereo microscope or a camera/monitor. Is there a
> marked advantage(s) of one versus the other?  I have no "floaters" to
> contend with.
> >
> > Steve, K8JQ
> >
> > On 8/11/2016 4:06 PM, Chuck Harris wrote:
> >> Lots of good suggestions have already been made, but for
> >> me, a boom style stereo microscope, with a distance between
> >> the objective, and the focal point of at least 3 inches works
> >> fairly well...
> >>
> >> One other thing that may force your decision, if you are
> >> older, your eyes will likely have lots of "floaters", which
> >> are debris that floats around in your eyeballs.  This debris
> >> floats in and out of the center of your field of view, and
> >> looks like a bunch of translucent worms, or shadows.
> >>
> >> Your brain, the magnificent organ that it is, tries to compensate
> >> for your eye's degradation, and as long as your eyes can move
> >> about in your field of view, it effectively removes the floaters
> >> from the scenes you are viewing.
> >>
> >> However, if you use a stereo microscope, your eye position
> >> is fixed by the very limited amounts of off axis motion
> >> that will allow a through optical channel.  This lack of off
> >> axis motion will emphasize your floaters in a great way, and you
> >> will see *every* *single* *one*, clearly, as if it were something
> >> you really wanted to view.  Some times, the floaters will cover
> >> the exact thing you need to see clearly, and you will have to
> >> move it off axis by moving it on the microscope stage.
> >>
> >> The only answer to this problem, is to either have perfect eyes,
> >> or to use a microscope where you are looking at a screen, rather
> >> than through a pair of oculars.  This way, your eyes can dart
> >> around, and inspect what they need to see clearly, and the
> >> floaters will be ignored by your brain.
> >>
> >> As far as I know, there is only one optical microscope built this
> >> way, and it is the very expensive Mantis.
> >>
> >> Because of the great expense of flat screen optical microscopes,
> >> most modern SMD viewing equipment is going to the trivially cheap
> >> method of using a CCD/CMOS color video camera and an LCD screen.
> >>
> >> You can do a lot with a cheap USB camera mounted to a boom, a fiber
> >> optic light source, or a ring light, and a laptop computer to
> >> display the image.
> >>
> >> -Chuck Harris
> >>
> >> Bob Albert via time-nuts wrote:
> >>> What are the important parameters regarding purchase of a stereo
> microscope?  I
> >>> see some on ebay for around $50; are those good? Bob
> >> ___
> >> time-nuts mailing list -- time-nuts@febo.com
> >> To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> >> and follow the instructions there.
> >>
> >
> > ___
> > time-nuts mailing list -- time-nuts@febo.com
> > To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> > and follow the instructions there.
>
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Re: [time-nuts] Anybody want a Thunderbolt power supply?

[Adrian Godwin]

I'm being Devil's Advocate here because I certainly realise switchers do
generate high frequency noise. But wasn't the intention of them to make
filtering easier, with smaller filter components, exactly because they
operate at higher frequencies ?

So why do they fail ? Is it cost-cutting to make them only just good enough
for typical uses ? Shouldn't it be possible to make the best possible
supply from a switcher, if only cost and weight weren't the first
considerations ?


On Wed, Aug 31, 2016 at 9:45 PM, Mark Sims  wrote:

> Yes,  at times I used a two stage linear regulator.  The first stage had
> excellent low freq rejection and the final stage too care of the high freq
> stuff.
>
> Some times a full linear supply is not a viable option due to power
> dissipation/size issues or the utter convenience of using a switching wall
> wart.
>
> 
>
> > Precisely the reason to avoid switchers entirely and use linear-only
> voltage regulators to power noise-sensitive circuits.  As I mentioned
> before, I had to use two stages of well-designed linear regulation to
> make any switching supply acceptable (at a time-nuts level) for use with
> a Tbolt.
> ___
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>
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Re: [time-nuts] Hobbyist grade or homebrew temperature testing chamber?

[Adrian Godwin]

On Tue, Sep 6, 2016 at 4:24 AM, Bob Darlington 
wrote:

> Rick,
>
> I'm going from memory here.  My former business partner (now deceased) had
> a "beer fridge" setup as an environmental chamber for our instruments.  The
> trick for stability was to run the AC compressor all the time, and push
> against it with heat lamps.



I had a commercial environmental chamber  : it did exactly this.  The
fridge unit could be controlled from an auxiliary output of the PID
controller but the basic principle was to heat from ambient, or heat
against the fridge for lower temperatures. Maybe Peltier systems can have a
cleaner rollover for cooling, but gas-based coolers have far too much
settling time / transients / hysteresis to be actively in the control loop.
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Re: [time-nuts] Measure GPSDO stability with minimum resources?

[Adrian Godwin]

Recently, I dumped the ROM from a ks24361. I imagine it's the same or very
similar code. Are there notes published somewhere ? It would be useful to
compare them.

On 7 Oct 2016 7:52 p.m., "Magnus Danielson" 
wrote:

> Hi Tom,
>
> On 10/07/2016 06:02 PM, Tom Van Baak wrote:
>
>> To expand on the replies by Bob and Magnus...
>>
>> Many years ago after pForth was discovered inside the entire hp 585xx and
>> Z38xx series "SmartClock" GPSDO, Magnus and I worked on the mystery of how
>> the 58503A GPSDO worked so well. HP appears to use a 64-entry circular
>> buffer to record hourly EFC history. Given 64 hours (2.7 days) of data, a
>> GPSDO can make a reasonable prediction of GPS reception or OCXO frequency
>> stability (via ADEV-like statistics) and frequency drift (via linear or
>> quadratic LSQ fits).
>>
>
> I found the big binary dump of the flash on Tom's page, and that he
> already found a bunch of strings.
>
> I've spent a lot of time to disassemble and decompile the code,
> identifying libc routines, decode the pForth, finding variables etc.
> It's a large piece of code to decrypt. The decompiler tool has bugs and
> crashes, and it turns out that only the older version is stable enough to
> do any useful work, and well there is no source-code. Part of the problem
> in decrypting the whole thing is to figure out the pSos routines. These
> hurdles aside, it's nice to see the code slowly come clear, figuring out
> routine for routine, variable after variable...
>
> It would be interesting to complete it some day, but ah well.
>
> Why 64 hours? Well, C programmers working with circular buffers like
>> powers of 2. And from personal experience working with GPSDO I know that
>> high sampling rates are mostly noise and not useful. So hourly EFC data
>> makes sense to me. Also from experience I know that less than one day of
>> EFC data can be misleading. Similarly more than a week of stale past data
>> can also be irrelevant to a prediction of 1 day into the future. So for all
>> these reasons, 64 hours seems an adequate choice.
>>
>
> Now, any other number would also work, it would not be too much code to do
> properly, but whenever power of 2 is achieveable, it is very handy in a
> binary system.
>
> For least-square estimation, higher number of samples provide steeper
> filters for the estimated parameters. A simple estimation of degrees of
> freedom would be number of samples minus estimated parameters plus one.
> However, 64 samples should be enough to get a fair idea with fairly good
> confidence interval, so it would kind of work good enough, which is the
> purpose here anyway.
>
> It would be nice to recreate more of these algorithms.
>
> Cheers,
> Magnus
>
> Note HP and other high-end GPSDO provide both a FFOM (frequency figure of
>> merit) and TFOM (time FOM) value via the SCPI interface. There is lots more
>> info on all these subjects scattered in the time-nuts archives. Here's an
>> example 58503 dump (log1348.txt):
>>
>> p4th D > pr_efc
>> efc = 280607.843750
>>
>> p4th D > pll_rep
>> start ptr = 7stop_ptr = 6
>> max loop time = -1412584448
>> ffom = 0
>> tfom = 1.0e-06 secs
>>
>> p4th D > efc_rep
>> 65.698517 282457.3 3
>> 66.698517 282468.8 3
>> 67.698517 282473.8 3
>> 68.698517 282485.2 3
>> 69.698517 282490.1 3
>> 70.698517 282496.9 3
>> 7.698519 280841.3 3
>> 8.698519 280943.2 3
>> 9.698519 281063.8 3
>> 10.698519 281126.8 3
>> 11.698519 281185.4 3
>> 12.698519 281259.0 3
>> 13.698519 281316.7 3
>> 14.698519 281353.4 3
>> 15.698519 281413.1 3
>> 16.698519 281464.9 3
>> 17.698519 281511.9 3
>> 18.698519 281567.6 3
>> 19.698519 281622.8 3
>> 20.698519 281634.8 3
>> 21.698519 281671.7 3
>> 22.698519 281705.8 3
>> 23.698519 281736.4 3
>> 24.698519 281768.2 3
>> 25.698519 281813.6 3
>> 26.698519 281847.9 3
>> 27.698519 281872.4 3
>> 28.698519 281899.0 3
>> 29.698519 281919.0 3
>> 30.698519 281950.0 3
>> 31.698519 281974.3 3
>> 32.698517 282001.1 3
>> 33.698517 282043.5 3
>> 34.698517 282054.2 3
>> 35.698517 282056.2 3
>> 36.698517 282060.2 3
>> 37.698517 282081.5 3
>> 38.698517 282092.2 3
>> 39.698517 282093.2 3
>> 40.698517 282094.1 3
>> 41.698517 282100.7 3
>> 42.698517 282127.8 3
>> 43.698517 282126.1 3
>> 44.698517 282143.3 3
>> 45.698517 282150.0 3
>> 46.698517 282162.9 3
>> 47.698517 282188.4 3
>> 48.698517 282213.4 3
>> 49.698517 282244.7 3
>> 50.698517 282255.4 3
>> 51.698517 282260.3 3
>> 52.698517 282280.5 3
>> 53.698517 282286.6 3
>> 54.698517 282307.0 3
>> 55.698517 282319.3 3
>> 56.698517 282336.2 3
>> 57.698517 282350.4 3
>> 58.698517 282367.3 3
>> 59.698517 282367.2 3
>> 60.698517 282395.8 3
>> 61.698517 282411.4 3
>> 62.698517 282430.3 3
>> 63.698517 282441.6 3
>> 64.698517 282450.1 3
>> a= 2.793488e+05 b= -2.535462e+00 c= 7.822419e+02
>> p4th D >
>>
>> /tvb
>>
>> - Original Message -
>> From: "Magnus Danielson" 
>> To: 
>> Cc: 
>> Sent: Thursday, October 06, 2016 3:40 PM
>> Subject: Re: [time-nuts] Measure GPSDO stability with minimum resources?
>>
>>
>> Hi,
>>
>> On 

Re: [time-nuts] Measure GPSDO stability with minimum resources?

[Adrian Godwin]

Yes, they're at
http://www.ko4bb.com/getsimple/index.php?id=manuals&dir=02_GPS_Timing/Lucent_KS-24361/KS24361-Z3812A-KR92830585-X98_4-A

On Sat, Oct 8, 2016 at 12:00 PM, Magnus Danielson <
mag...@rubidium.dyndns.org> wrote:

> Hi Adrian,
>
> Except what Tom published on the Z3801A there is no more published notes
> as far as I know. I can see what of my project is easy to share though.
>
> Is the images uploaded somewhere?
>
> Cheers,
> Magnus
>
>
> On 10/07/2016 10:06 PM, Adrian Godwin wrote:
>
>> Recently, I dumped the ROM from a ks24361. I imagine it's the same or very
>> similar code. Are there notes published somewhere ? It would be useful to
>> compare them.
>>
>> On 7 Oct 2016 7:52 p.m., "Magnus Danielson" 
>> wrote:
>>
>> Hi Tom,
>>>
>>> On 10/07/2016 06:02 PM, Tom Van Baak wrote:
>>>
>>> To expand on the replies by Bob and Magnus...
>>>>
>>>> Many years ago after pForth was discovered inside the entire hp 585xx
>>>> and
>>>> Z38xx series "SmartClock" GPSDO, Magnus and I worked on the mystery of
>>>> how
>>>> the 58503A GPSDO worked so well. HP appears to use a 64-entry circular
>>>> buffer to record hourly EFC history. Given 64 hours (2.7 days) of data,
>>>> a
>>>> GPSDO can make a reasonable prediction of GPS reception or OCXO
>>>> frequency
>>>> stability (via ADEV-like statistics) and frequency drift (via linear or
>>>> quadratic LSQ fits).
>>>>
>>>>
>>> I found the big binary dump of the flash on Tom's page, and that he
>>> already found a bunch of strings.
>>>
>>> I've spent a lot of time to disassemble and decompile the code,
>>> identifying libc routines, decode the pForth, finding variables etc.
>>> It's a large piece of code to decrypt. The decompiler tool has bugs and
>>> crashes, and it turns out that only the older version is stable enough to
>>> do any useful work, and well there is no source-code. Part of the problem
>>> in decrypting the whole thing is to figure out the pSos routines. These
>>> hurdles aside, it's nice to see the code slowly come clear, figuring out
>>> routine for routine, variable after variable...
>>>
>>> It would be interesting to complete it some day, but ah well.
>>>
>>> Why 64 hours? Well, C programmers working with circular buffers like
>>>
>>>> powers of 2. And from personal experience working with GPSDO I know that
>>>> high sampling rates are mostly noise and not useful. So hourly EFC data
>>>> makes sense to me. Also from experience I know that less than one day of
>>>> EFC data can be misleading. Similarly more than a week of stale past
>>>> data
>>>> can also be irrelevant to a prediction of 1 day into the future. So for
>>>> all
>>>> these reasons, 64 hours seems an adequate choice.
>>>>
>>>>
>>> Now, any other number would also work, it would not be too much code to
>>> do
>>> properly, but whenever power of 2 is achieveable, it is very handy in a
>>> binary system.
>>>
>>> For least-square estimation, higher number of samples provide steeper
>>> filters for the estimated parameters. A simple estimation of degrees of
>>> freedom would be number of samples minus estimated parameters plus one.
>>> However, 64 samples should be enough to get a fair idea with fairly good
>>> confidence interval, so it would kind of work good enough, which is the
>>> purpose here anyway.
>>>
>>> It would be nice to recreate more of these algorithms.
>>>
>>> Cheers,
>>> Magnus
>>>
>>> Note HP and other high-end GPSDO provide both a FFOM (frequency figure of
>>>
>>>> merit) and TFOM (time FOM) value via the SCPI interface. There is lots
>>>> more
>>>> info on all these subjects scattered in the time-nuts archives. Here's
>>>> an
>>>> example 58503 dump (log1348.txt):
>>>>
>>>> p4th D > pr_efc
>>>> efc = 280607.843750
>>>>
>>>> p4th D > pll_rep
>>>> start ptr = 7stop_ptr = 6
>>>> max loop time = -1412584448
>>>> ffom = 0
>>>> tfom = 1.0e-06 secs
>>>>
>>>> p4th D > efc_rep
>>>> 65.698517 282457.3 3
>>>> 66.698517 282468.8 3
>>>> 67.698517 282473.8 3
>>

Re: [time-nuts] TimeLab

[Adrian Godwin]

On Sun, Oct 9, 2016 at 9:07 PM, Tom Van Baak  wrote:

> 3) The problems you are running into get far worse the less accurate and
> less stable the sources are (such as mains, mechanical, vintage quartz, and
> pendulum clocks). So that's why I developed the picPET time-stamping
> counter. It's 400 ns resolution is not good enough for you. Even the new 10
> ns version isn't good enough for your needs.
>
>
10ns ?
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Re: [time-nuts] For those that insist on using switching power supplies

[Adrian Godwin]

I would add a DC blocker for the input to the spectrum analyser.


On Fri, Oct 14, 2016 at 7:59 PM, Hal Murray  wrote:

>
> time-nuts@febo.com said:
> >> Nick, thanks for your detailed reply.  Would you happen to have a photo
> of
> >> the "spring looking things?"  I am not entirely sure I have one of those
> >> included with the kit that came with the scope.
>
> > I don’t have a picture, but the Internet does: http://i.stack.imgur.com/
> > PSo3N.jpg
>
> The other tool to add to your collection is coax and a soldering iron.  I
> make them in pairs by starting with a BNC-BNC jumper and cutting it in
> half.
> The thin (high-loss) coax is easier to work with and the loss over a few
> feet
> probably won't be a big deal.
>
> --
> These are my opinions.  I hate spam.
>
>
>
>
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Re: [time-nuts] PC clock generator without 14.318MHz

[Adrian Godwin]

How about the Apollo launches ?


On Wed, Oct 19, 2016 at 12:40 AM, jimlux  wrote:

> On 10/18/16 4:25 PM, Magnus Danielson wrote:
>
>> Jim,
>>
>> On 10/19/2016 12:51 AM, jimlux wrote:
>>
>>> On 10/18/16 2:30 PM, Tom Van Baak wrote:
>>>
 Hi Vladimir,

 Some of these numbers survive to the present. I'm typing this post on
 an XP laptop where QueryPerformanceCounter() has a Frequency.QuadPart
 of, you guessed it, 3579545 Hz, which is why my Win32 laptop's
 high-res clock has ~279 ns resolution.

 For more fun with time, frequency, oscillators, and prime numbers,
 see: http://www.poynton.com/PDFs/Magic_Numbers.pdf


>>> and this is why clocks in film movies on TV run slightly slow..
>>> because the film was shot at 24 fps, and it's converted to 29.97 frame
>>> rate (in the US) by a 3:2 pulldown scheme.
>>>
>>> I am sure that all the time nuts here notice that 0.1% rate difference.
>>> Over a half hour TV program it adds up to almost 2 seconds of offset.
>>> (that's just because we watch things like movies shot of counters
>>> running).
>>>
>>> Hmm.. there's probably film footage of things with a running counter in
>>> the scene counting tenths or hundredths of a second (sporting events,
>>> nuclear bomb tests, etc.) I wonder if you could see that difference by
>>> single framing something like a filmed 100 meter race where they have an
>>> onscreen timer.
>>>
>>
>> The time-code of TV and film production runs with a frame-counter.
>> Now, since the 30/1.001 factor is uneven, to get things into shape the
>> factor is compensated using the drop-frame method.
>>
>
> SO that compensates in the "big sense" so that "timecode" and "wall clock"
> line up..
>
> But when they do the original telecine, they're basically running a 30fps
> (interpolated from 24 fps) sequence of frames at 29.97.  Over the air,
> there will usually be a commercial break and they can add/drop any
> arbitrary number of frames to get it to line up (should they even care
> about whether the on-screen clock ticking the seconds actually lines up)
>
> So I was thinking about something where you get a broadcast (or maybe a
> video conversion on DVD/tape/online) that is a continuous piece of film.
>
> Seems that something like 100 meter race, which lasts 10 seconds, and will
> have an on screen timer to hundredths isn't quite long enough to see the
> 1.001 error (and would it be one continuous shot, or would they have edited
> film together from different viewpoints).
>
> What about a filmed rocket launch with a countdown timer or similar? they
> might have one continuous piece of film long enough.
>
> Partly, its going to be limited by the magazine size of the camera: a 400
> ft magazine is a bit more than 6 minutes (1 ft = 1 second in rough terms),
> so that's plenty long to see the difference.
>
> What you really want is continuous footage lasting, say, a minute, of some
> event (motivating the coverage) where there's an accurate clock visible in
> the scene, where the film was originally shot at 24fps, and has been
> converted to video.
>
> An interesting quest
>
>
>
>
>
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Re: [time-nuts] KSC big clock

[Adrian Godwin]

Wow .. 24kW for a clock display !


On Fri, Oct 21, 2016 at 6:56 AM, Todd Caldwell  wrote:

> Hi All,
>
>   I've been lurking and assembling gear for the most part, so this is my
> first post I think.
>
>   I was at KSC in May of 2010 for the launch of STS-132.  Attached is a
> relatively closeup pic of the old countdown clock near the press area. As I
> recall, the bulbs are 100W incandescent.  LOTS of them.
>
>   Sadly, they've replaced it with a HDTV like setup of some kind since.
> Video would have been nice I suppose, but the old clock had character.
>
>   Todd - K5SLR.
>
>
> On 10/20/16 04:51, Blair Lade wrote:
>
>> The KSC clock might just use fluroscent tubes in a 7 segment display
>> configuration.Pretty easy to do, just put a set of relay contacts inplace
>> of the starter in the circuit, close the contact, fluro turns off, current
>> flows through heater / filiment keeping them warm.Open the contact, fluro
>> lights..Drive relays off bcd to seven segment decoders, etcWhile it's a bit
>> nasty on the fluro tubes when in the off condition, they are cheap..and the
>> duty cycle isnt all that bad.In actual practise, the relays suffer more
>> than the tubes, and they are cheap too!
>> Blair South Australia
>>
>>
>> Sent from Samsung tablet.
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Re: [time-nuts] Linux PPS clues?

[Adrian Godwin]

What is the circuit driving that signal ? It appears to have too little
positive drive to overcome the capacitance. Perhaps it's an open collector
with too large a pull-up ?

On 21 Oct 2016 12:23 a.m., "Ilia Platone"  wrote:

> sorry, no attachment, this mail contains two images, one is the previous
> attempt, the second (IMG_003.JPG) was taken at 5us/div, 1v/div with a
> different oscilloscope setup.
>
> Best Regards,
> Ilia.
>
> On 10/20/16 18:12, Attila Kinali wrote:
>
>> On Thu, 20 Oct 2016 10:59:21 +0100
>> "David J Taylor"  wrote:
>>
>> Actually, of the 15 Raspberry Pi cards I have only one is used in a
>>> graphics
>>> application.
>>>
>> Yes, the rpi are used for all kind of stuff and there is a huge community
>> around them that helps with all kind of questions. Unfortunately, the
>> rpi is also used for all kind of stuff that it is a suboptimal choice
>> (to put it mildly), but people do not care or do not want to check
>> for alternatives. It kind of works, that's all they care about.
>>
>> On the positive side they work very well with external devices for control
>>> and measurement,
>>>
>> And for most of these applications a 32bit uC that uses a fraction of
>> the power would be the right choice. Often a clock of 1MHz would be
>> enough.
>>
>> and have a huge amount of software and hardware support for
>>> a vast range of devices which makes for fast and easy development.
>>>
>> That's the only plus side. But then, most of the code written in C
>> can be used on a uC just the same with little to no modification.
>>
>> I will be interested to see what is recommended for a 100 kHz event rate.
>>>
>> This is actually a very tough question. 100kHz means that for each event
>> there is only 10µs available for detection, processing and output. Using
>> a uC that would be something in the order of 1000-2000 CPU cycles. On an
>> application processor (rpi and its cusins) that would be 2000 to 20'000
>> cycles.
>> While 1000 cycles on a uC is quite a lot, you cannot do any fancy
>> processing
>> with so few cycles.
>>
>> On the application processor 20k cylces is plenty, but you have the
>> complex
>> OS that eats up a few thousand cycles itself. Addtionally there comes
>> the interrupt latency that the application processors suffer from, which
>> is in the order of 1-10µs... So they would need a kind of (hardware)
>> system
>> to queue up the events to process them in badges. Because of this, an rpi
>> wouldn't work at all (bitbanging takes several µs for each operation).
>>
>> Going for an uC is easier in that regard as they have very little
>> interrupt
>> latency (usually just 5-10 cycles), but then you have problems with
>> getting the output out of the uC as their I/O subsystems are usually
>> optimized to work in a stand-alone fashion.
>>
>> Maybe one way would be to use an arm9/cortex-a5 based uC (ie not an
>> application
>> processor) and use their high speed I/O.
>>
>> For better answers, I would need to know what kind of events these are
>> and what exactly need to be done/measured.
>>
>> Attila Kinali
>>
>>
>>
> --
> Ilia Platone
> via Ferrara 54
> 47841
> Cattolica (RN), Italy
> Cell +39 349 1075999
>
>
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Re: [time-nuts] Opening an Isotemp OCXO

[Adrian Godwin]

That's one sweet soldering iron. Is it an American Beauty ?


On Fri, Oct 28, 2016 at 4:31 PM, Peter Reilley 
wrote:

> I did finally get it open.   I used a very large old style soldering
> iron and .003 inch steel shim stock.   I would melt the solder on the
> straight seams and insert small pieces of the shim.   Solder does not
> stick well to steel so the shim kept the soldered seam open.
> I used a soldering iron rather than a torch because I can control the
> temperature.
>
> I could not use the shim at the corners.   After all the straight seams
> were separated I could pull each corner using a screw in the mounting
> hole and melt the solder at the corner.   Slowly working my way around,
> corner by corner, I got it opened.   I did not damage anything so I
> should be able to close it up after I fix it.
>
> Looking around with my scope it seems that the output driver chip is bad
> as I expected.   It is a TI 14 pin surface mount DIP.   It says S30 on it
> which if it is a 74S30 it is an 8 input positive NAND gate.   The board
> layout confirms this as the 10 MHz signal is connected to pin 2 and all
> other inputs are tied high.   Pin 8 is connected to the output.
>
> The chip is run off 12 volts so it must be CMOS.   But I cannot find any
> chip like that that will run off 12 volts.   Any suggestions for a
> replacement?
>
> Also, using an 8 input NAND chip for a driver seems an odd choice.
>
> When I put 12 volts on the unit the S30 chip gets really hot. After I
> removed the chip the unit seems to work OK.   The current jumps between
> about .1 amp to .9 amps.   It seems like the temperature regulator is
> an on/off type controller.
>
> The device on eBay, item 261920574725, looks exactly like what I have.
>
> I have placed a bunch of pictures in my dropbox.
> https://www.dropbox.com/sh/52e9d1rva9kpb3w/AABmbIj1aK7Zk2J9SNMmu-JAa?dl=0
>
> Pete.
>
>
>
>
> On 10/18/2016 10:57 AM, J. L. Trantham wrote:
>
>> Pete,
>>
>> I'm not familiar with your OCXO but I found one shown on 'theBay' (item
>> 261920574725) and it appeared to have an option for 'mounting screws', four
>> of them, on the bottom.  Interestingly, the 'link' to the datasheet for
>> that unit did not show threads for mounting screws.
>>
>> If your unit has that option, I would suggest placing four long screws,
>> mounting the item in a vise, use a small torch (I've used a hand held
>> propane torch turned down very low to open a number of units from 5061A's)
>> around the bottom of the case while gripping the top with an appropriate
>> sized Channel Lock plier and lifting off the top.
>>
>> If you can repair the OCXO, it should be easy to reassemble the unit with
>> solder.
>>
>> TheBay unit looks like it has a screw cover (which likely has a rubber
>> gasket) for mechanical adjustment of the frequency.  I'd remove that before
>> applying the torch. :^).
>>
>> If you get it open, I'd love to see some pictures of the insides.
>>
>> Good luck and hope this helps.
>>
>> Joe
>>
>>
>>
>> -Original Message-
>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Peter
>> Reilley
>> Sent: Tuesday, October 18, 2016 8:11 AM
>> To: time-nuts@febo.com
>> Subject: [time-nuts] Opening an Isotemp OCXO
>>
>> 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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>>
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Re: [time-nuts] Opening an Isotemp OCXO

[Adrian Godwin]

The 1k resistor doesn't seem to feed the 'S30'. It looks as though pin 14
(Vcc) goes via that thick track to the +12 input.

On Fri, Oct 28, 2016 at 5:46 PM, jimlux  wrote:

> On 10/28/16 8:31 AM, Peter Reilley wrote:
>
> Looking around with my scope it seems that the output driver chip is bad
>> as I expected.   It is a TI 14 pin surface mount DIP.   It says S30 on it
>> which if it is a 74S30 it is an 8 input positive NAND gate.   The board
>> layout confirms this as the 10 MHz signal is connected to pin 2 and all
>> other inputs are tied high.   Pin 8 is connected to the output.
>>
>> The chip is run off 12 volts so it must be CMOS.   But I cannot find any
>> chip like that that will run off 12 volts.   Any suggestions for a
>> replacement?
>>
>> Also, using an 8 input NAND chip for a driver seems an odd choice.
>>
>>
> could it be some sort of 74C series? if it's intended to run off 12V, a
> lot of the CMOS parts can run at almost any Vdd (a virtue of 4000 series
> CMOS - 15V power, no problem)
>
> Maybe they got a good price on the 8 input NAND parts?
>
> If unused pins are tied high, it's unlikely that they are outputs - most
> parts are either a totem pole or open collector output, neither one of
> which would like being tied high.
>
>
>
>
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Re: [time-nuts] Opening an Isotemp OCXO

[Adrian Godwin]

The data sheet for the device only mentions 12V. Other data sheets (eg the
131) mention 5V and 12V, but don't indicate how to specify one or the
other.

Gerry Sweeny's article at
http://gerrysweeney.com/diy-hpagilent-53131a-010-high-stability-timebase-option/
mentions a part number suffix that distinguishes two choices but this
doesn't appear in the main datasheet. Other writers here have in the past
mentioned that the suffix has no predefined meaning and is used only to
distinguish design variants internally.

It appears that Isotemp do offer a choice of voltage options but don't like
to document it publicly. Tom Miller's strategy seems the safest if using a
surplus device.

On Fri, Oct 28, 2016 at 8:10 PM, Peter Reilley 
wrote:

> The reason that there was 12 volts on the unit was because I put it
> there.   I should
> have tried 5 volts first but the only datasheet that I could find said 12
> volts.
> All the eBay units that look the same say 12 volts.
>
> Pete.
>
>
> On 10/28/2016 12:53 PM, paul swed wrote:
>
>> I confirmed the pin out matches a 74s30 also. An S30 is TTL. Great pix to
>> look at.
>> So 12 V on a 5 V chip is indeed a smoker. Find out why there was 12 V.
>> OK crazy talk I see a 1K resistor next to the VCC chip. Would anyone be
>> crazy enough to use a dropping resistor from 12 V to get 5?? Really bad
>> engineering and I don't actually believe they would. But if true a open
>> 74s30 would indeed show 12 V on pin 14.
>> Good luck.
>> Paul
>> WB8TSL
>>
>> On Fri, Oct 28, 2016 at 12:48 PM, jimlux  wrote:
>>
>> On 10/28/16 9:13 AM, Scott Stobbe wrote:
>>>
>>> The OCXO82-59 datasheet lists 12V supply, 5V clock out, could also be a
 blown regulator in your ocxo, if it is indeed a 12v model.

 There you go..the design could use a 74S30 as a driver - it's fast,

>>> fairly good drive, but runs off 5V.  If the regulator is shorted, and you
>>> put 12V on it, it will cook.
>>>
>>>
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Re: [time-nuts] I love the smell of tantalum in the morning

[Adrian Godwin]

Metcal /OKI might be that other brand. I'd certainly recommend them, but
the tweezers are not as fast to heat as the single tip devices.

I've had little success personally with the hot air devices. I seem to
toast the board before I melt the solder, and when it does melt it's not
limited to one component. Doubtless it's my technique at fault, but I
prefer the tweezers.






On Sat, Nov 5, 2016 at 7:20 PM, 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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Re: [time-nuts] I love the smell of tantalum in the morning

[Adrian Godwin]

SMD parts aren't going to go away. It's worth investing in good tools to
deal with them and learning the best way to use them.

I'd put tweezers quite high on that list, and although the metcals are
worthwhile if you can avoid full price, the chinese tweezers are
surprisingly useful at very low cost. Buy them to explore their deficiences
and buy better when you know what you really need.

On Sun, Nov 6, 2016 at 4:53 PM, Clint Jay  wrote:

> Heating one end and adding a little solder to the joint will allow you to
> lift the cap,  the leads are folded over tabs so they'll bend nicely and
> allow the cap to lift,  once you've got one end lifted,  heat the other and
> it will come away easily.
>
> Clean up the pads with solder wick then you're good to replace the part.
>
> While I'd like an excuse (and the funds)  to buy a pair of tweezers for
> SMD,  I'd find it hard to use that job as an excuse.
>
> On 5 Nov 2016 19:12, "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?
> >
> > Thanks,
> > /tvb
> >
> > [0] http://www.imdb.com/title/tt0078788/quotes
> > [1] http://leapsecond.com/museum/hp5071a/A1-mother.htm
> >
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Re: [time-nuts] I love the smell of tantalum in the morning

[Adrian Godwin]

I agree - I find them totally useless for applying solder. I'd only use
them for removing parts. To solder them, clean the pads as described here
and solder one end at a time.


On Sun, Nov 6, 2016 at 5:24 PM, Scott Stobbe 
wrote:

> I would not recommend purchasing soldering tweezers without trying them
> first. They are not easy to control solder application when mounting a
> component.
>
>  I do really like the Weller rt7 knife tip.
>
> On Sunday, 6 November 2016, Adrian Godwin  wrote:
>
> > SMD parts aren't going to go away. It's worth investing in good tools to
> > deal with them and learning the best way to use them.
> >
> > I'd put tweezers quite high on that list, and although the metcals are
> > worthwhile if you can avoid full price, the chinese tweezers are
> > surprisingly useful at very low cost. Buy them to explore their
> deficiences
> > and buy better when you know what you really need.
> >
> > On Sun, Nov 6, 2016 at 4:53 PM, Clint Jay  > > wrote:
> >
> > > Heating one end and adding a little solder to the joint will allow you
> to
> > > lift the cap,  the leads are folded over tabs so they'll bend nicely
> and
> > > allow the cap to lift,  once you've got one end lifted,  heat the other
> > and
> > > it will come away easily.
> > >
> > > Clean up the pads with solder wick then you're good to replace the
> part.
> > >
> > > While I'd like an excuse (and the funds)  to buy a pair of tweezers for
> > > SMD,  I'd find it hard to use that job as an excuse.
> > >
> > > On 5 Nov 2016 19:12, "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?
> > > >
> > > > Thanks,
> > > > /tvb
> > > >
> > > > [0] http://www.imdb.com/title/tt0078788/quotes
> > > > [1] http://leapsecond.com/museum/hp5071a/A1-mother.htm
> > > >
> > > > ___
> > > > time-nuts mailing list -- time-nuts@febo.com 
> > > > To unsubscribe, go to https://www.febo.com/cgi-bin/
> > > > mailman/listinfo/time-nuts
> > > > and follow the instructions there.
> > > >
> > > ___
> > > time-nuts mailing list -- time-nuts@febo.com 
> > > To unsubscribe, go to https://www.febo.com/cgi-bin/
> > > mailman/listinfo/time-nuts
> > > and follow the instructions there.
> > >
> > ___
> > time-nuts mailing list -- time-nuts@febo.com 
> > To unsubscribe, go to https://www.febo.com/cgi-bin/
> > mailman/listinfo/time-nuts
> > and follow the instructions there.
> >
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Re: [time-nuts] I love the smell of tantalum in the morning

[Adrian Godwin]

You might also want normal cold tweezers to place the part. I'm not sure
what an orange stick is, around here I'd use a wooden toothpick. Perhaps
that's the same thing !

The Swiss Venus tweezers have a lovely finish and the ends always meet.
There are probably others as good.

If you get some placing tweezers, make sure they're antimagnetic. Some
small parts (even resistors, that I wouldn't expect to contain steel) seem
to stick even to stainless steel. I've also heard bambooo tweezers are
good, but have never tried them.


On Sun, Nov 6, 2016 at 6:17 PM, jimlux  wrote:

> On 11/6/16 9:24 AM, Scott Stobbe wrote:
>
>> I would not recommend purchasing soldering tweezers without trying them
>> first. They are not easy to control solder application when mounting a
>> component.
>>
>
> tweezers to remove
> single iron to install
> use a orange stick to hold the part down while you solder each end.
>
>
>
>
>
>
>
> ___
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Re: [time-nuts] Time nut soon to be in Shenzhen

[Adrian Godwin]

Ref. the thread about burning tantalum capacitors .. If I were going to
china I'd be looking at the tools. Many might be low quality (but cheaper
than ebay). Others might be excellent. You need to see them to find out.

On Sun, Nov 6, 2016 at 4:33 PM, Azelio Boriani 
wrote:

> Maybe I have a clue: on the usual auction site there is a new seller
> (since April 2015) from ShenZhen (Guangdong provice) that has a lot of
> OCXOs on sale. Not so far (~140km) there is another OCXOs seller
> (since 2005) in Guangzhou, the capital of Guangdong province.
>
> On Sun, Nov 6, 2016 at 4:43 PM, paul swed  wrote:
> > Sorry no clue I suspect you will be the Marco Polo of time-nuttery.
> > Have fun and remember pennies per pound. You can have a lot of fun at
> that
> > cost.
> > Regards
> > Paul
> > WB8TSL
> >
> > On Sun, Nov 6, 2016 at 10:13 AM, Christopher Hoover 
> > wrote:
> >
> >> 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
> >> ___
> >> time-nuts mailing list -- time-nuts@febo.com
> >> To unsubscribe, go to https://www.febo.com/cgi-bin/
> >> mailman/listinfo/time-nuts
> >> and follow the instructions there.
> >>
> > ___
> > time-nuts mailing list -- time-nuts@febo.com
> > To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> > and follow the instructions there.
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> and follow the instructions there.
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[time-nuts] HP 5275A

[Adrian Godwin]

Slightly off-topic, as this is a general repair question. But it's a TIC.

I'm repairing a 5275A timer (all-discreet count logic to 100MHz, neon bulb
display, a most amazing bcd to decimal decoder made from neons and LDRs,
1-2-2-4 decade counters ..) and the current problem is a 2n1038-2 germanium
T05 transistor in the power supply.

It's mounted in an aluminium bush which is then isolated from the chassis.
I don't think the bush is also a collet but I can't see how to remove the
transistor. It resists ungentle pushing .. should I push it with a hammer ?
Or is there a kinder way ?

(I'm hoping to eventually put this into a system with a 101A oscillator and
a 9815A calculator to measure the ADEV of a Boule electric pendulum clock).
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Re: [time-nuts] HP 5275A

[Adrian Godwin]

Yes, further searching reveals that although the 2n1038 is T05, the -2
version is X26 - mounted in a stud by the factory. So it could well be
glued. 2N1038s aren't unobtainable though, so I'll keep it original if I
can. Even though a 7915 would be fine !

I was a bit puzzled by the insulators. Very metallic-looking. Then I
realised they're BeO. Pretty unusual these days (no, I won't be machining
them) so another reason to keep a T05 in there.

On Sun, Nov 6, 2016 at 10:46 PM, djl  wrote:

> Just homemade opto-isolators. Used in choppers, too. The transistor was
> indeed bonded to the heatsink.  Just replace the whole thing with a
> 3-legged regulator? or simply a modern PNP t0-220 with a little heat sink
> on it.
> 73, Don
>
>
>
> On 2016-11-06 15:15, paul swed wrote:
>
>> Don't know what to say on the transistor. It may have been actually made
>> that way. They did lots of things back then. Yes familiar with the bcd
>> decoder its used in the 5245 class counters also. I think someone was
>> doing
>> some funny stuff at lunch time to come up with that. It was the 60's after
>> all.
>> How about some pix of a 9815 calc. That would be pretty neat.
>> On really old stuff if you can't find the part needed its pretty easy to
>> replace the whole function with modern answers. I know it sort of breaks
>> the original mode but for me at least its a case of getting it going.
>> Regards
>> Paul
>> WB8TSL
>>
>> On Sun, Nov 6, 2016 at 1:59 PM, Adrian Godwin 
>> wrote:
>>
>> Slightly off-topic, as this is a general repair question. But it's a TIC.
>>>
>>> I'm repairing a 5275A timer (all-discreet count logic to 100MHz, neon
>>> bulb
>>> display, a most amazing bcd to decimal decoder made from neons and LDRs,
>>> 1-2-2-4 decade counters ..) and the current problem is a 2n1038-2
>>> germanium
>>> T05 transistor in the power supply.
>>>
>>> It's mounted in an aluminium bush which is then isolated from the
>>> chassis.
>>> I don't think the bush is also a collet but I can't see how to remove the
>>> transistor. It resists ungentle pushing .. should I push it with a
>>> hammer ?
>>> Or is there a kinder way ?
>>>
>>> (I'm hoping to eventually put this into a system with a 101A oscillator
>>> and
>>> a 9815A calculator to measure the ADEV of a Boule electric pendulum
>>> clock).
>>> ___
>>> time-nuts mailing list -- time-nuts@febo.com
>>> To unsubscribe, go to https://www.febo.com/cgi-bin/
>>> mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>>
>>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/m
>> ailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>
> --
> Dr. Don Latham
> PO Box 404, Frenchtown, MT, 59834
> VOX: 406-626-4304
>
>
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>
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Re: [time-nuts] HP 5275A

[Adrian Godwin]

I'm pleased to report this TIC is now running again (albeit with some
temporary hacks, such as a 7915 regulator).

There were a couple of dried-out electrolytics, the shorted series-pass
regulator referred to above, and an open-circuit 2N708 controlling the
timebase gating. Another 2N708 died when I failed to push a PCB fully into
its socket. They're rather delicate flowers - Silicon, but only 15V Vceo :
a bit tight when used as switches with a 15V or 13V rail. Replaced with
BC237s, though that's perhaps a bit slow.

This is the HP5275A from france that  Poul-Henning Kamp mentioned in march
2015. It's been sitting here a while waiting for some attention
​
 VID_20161109_003111.mp4
<https://drive.google.com/file/d/0B8q6sqvuGdFfMDI2aXA0NnFWRTg/view?usp=drive_web>


Paul Swed : I'll add some HP9815 porn when I get it reading the 5275A
outputs.


On Mon, Nov 7, 2016 at 2:46 AM, Howard Davidson  wrote:

> The real hack in the 5245 Nixie tube decoder is that the neon lamps were
> the memory element.
>
>
> hld
>
>
>
> On 11/6/2016 2:15 PM, paul swed wrote:
>
>> Don't know what to say on the transistor. It may have been actually made
>> that way. They did lots of things back then. Yes familiar with the bcd
>> decoder its used in the 5245 class counters also. I think someone was
>> doing
>> some funny stuff at lunch time to come up with that. It was the 60's after
>> all.
>> How about some pix of a 9815 calc. That would be pretty neat.
>> On really old stuff if you can't find the part needed its pretty easy to
>> replace the whole function with modern answers. I know it sort of breaks
>> the original mode but for me at least its a case of getting it going.
>> Regards
>> Paul
>> WB8TSL
>>
>> On Sun, Nov 6, 2016 at 1:59 PM, Adrian Godwin 
>> wrote:
>>
>> Slightly off-topic, as this is a general repair question. But it's a TIC.
>>>
>>> I'm repairing a 5275A timer (all-discreet count logic to 100MHz, neon
>>> bulb
>>> display, a most amazing bcd to decimal decoder made from neons and LDRs,
>>> 1-2-2-4 decade counters ..) and the current problem is a 2n1038-2
>>> germanium
>>> T05 transistor in the power supply.
>>>
>>> It's mounted in an aluminium bush which is then isolated from the
>>> chassis.
>>> I don't think the bush is also a collet but I can't see how to remove the
>>> transistor. It resists ungentle pushing .. should I push it with a
>>> hammer ?
>>> Or is there a kinder way ?
>>>
>>> (I'm hoping to eventually put this into a system with a 101A oscillator
>>> and
>>> a 9815A calculator to measure the ADEV of a Boule electric pendulum
>>> clock).
>>> ___
>>> time-nuts mailing list -- time-nuts@febo.com
>>> To unsubscribe, go to https://www.febo.com/cgi-bin/
>>> mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>>
>>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/m
>> ailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>>
> --
> Howard L. Davidson
> hl...@att.net
>
>
> ___
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Re: [time-nuts] 5071A with ATTENTION flashing

[Adrian Godwin]

I'm still struggling to get the acrylic I need. I've been into London a few
times but not been able to get to the shop in business hours. Guess I could
order online if necessary but it will cost a fair bit more.

On Wed, Nov 9, 2016 at 3:19 PM, paul swed  wrote:

> I saw the low CBT temp also and 10 degrees C seem like allot. However in
> the 5060/5061 Frankenstein I run the oven at +10 degrees (approx.) to what
> the tube asks for. To drive C fumes out of the oven. A possible assumption
> is the cooler oven is emitting fewer C's and the emult is trying to make up
> for it.
>
> Li
> If it were mine and I checked the other suggestions. I would if convenient
> actually attempt to raise the oven temp a bit to see what happens. I would
> measure current and use an external supply to match it and then gently
> increase the current. But from the thread you do not own it and I think a
> large amount of money was at stake.
>
> Regards
> Paul
> WB8TSL
>
>
> On Wed, Nov 9, 2016 at 7:52 AM, Scott McGrath  wrote:
>
> > that's telling you that the CBT oven is not up to temp  so you could have
> > a failed heater in the tube or the oven controller is malfunctioning
> >
> > The former well you need a new tube which symmetricom will be happy to
> > sell you for a 5 figure price tag.
> >
> > The latter is limited by your repair skills and parts and data
> availability
> >
> > Content by Scott
> > Typos by Siri
> >
> > > On Nov 9, 2016, at 7:42 AM, Li Ang <379...@qq.com> wrote:
> > >
> > > According to the Log, "CBT Oven Err: -9.55 C" might be something wrong.
> > However, I can't find the correct range in the manual. Does anyone have
> the
> > information about this parameter?
> > >
> > >
> > > Regards
> > > Li Ang
> > >
> > >
> > >
> > >
> > > -- Original --
> > > From:  "Li Ang";<379...@qq.com>;
> > > Date:  Wed, Nov 9, 2016 02:48 PM
> > > To:  "Tom Van Baak"; "Discussion of precise time
> > and frequency measurement";
> > >
> > > Subject:  Re: [time-nuts] 5071A with ATTENTION flashing
> > >
> > >
> > >
> > > Hi Tom
> > >
> > > I have collected the log from it. Log level is service. The 9.2G pll
> > pass the test today. The log during the power-up process is also
> included.
> > >
> > >
> > > Regards
> > >
> > > Li Ang / BI7LNQ
> > >
> > > -
> > >
> > >
> > >
> > > scpi >
> > >
> > > MJD0 02:02:18
> > >
> > > CBT ID: 3128A00642(H)
> > >
> > > Status summary: Fatal Error (see Log)
> > >
> > > Power source: AC
> > >
> > > Log status: One entry
> > >
> > >
> > > Freq Offset:  0e-15  Osc. control: -9.56 %
> > >
> > > RF amplitude 1: 6.3 %RF amplitude 2: 6.3 %
> > >
> > > Zeeman Freq:  39949 Hz   C-field curr:12.213 mA
> > >
> > > E-multiplier:  2553 VSignal Gain:   14.4 %
> > >
> > >
> > > CBT Oven:   0.0 VCBT Oven Err: -9.55 C
> > >
> > > Osc. Oven: -9.1 VIon Pump:   0.4 uA
> > >
> > > HW Ionizer:-0.1 VMass spec:12.3 V
> > >
> > > SAW Tuning: 0.0 VDRO Tuning: 7.3 V
> > >
> > > 87MHz PLL:  0.8 VuP Clock PLL:   1.8 V
> > >
> > > +12V supply:   12.3 V-12V supply:  -12.3 V
> > >
> > > +5V  supply:5.4 VThermometer:   46.2 C
> > >
> > >
> > >
> > > scpi >
> > >
> > > scpi > ?
> > >
> > > E-103> exit
> > >
> > > E-113>
> > >
> > > E-113> Log status: One entry
> > >
> > >
> > > Log 000 of MJD0 00:12:40:  Low Cs signal (60) with max Emult
> > >
> > >
> > > PASS: CBT register test
> > >
> > > PASS: CBT window comp test
> > >
> > > PASS: CBT therm test
> > >
> > > PASS: CBT Cs oven test
> > >
> > > PASS: CBT hw ion test
> > >
> > > PASS: CBT mass spec test
> > >
> > > PASS: CPU RTDS test
> > >
> > > PASS: CPU clock locked test
> > >
> > > PASS: DDFS register test
> > >
> > > PASS: 87MHz PLL test
> > >
> > > PASS: 9.2 GHz PLL test
> > >
> > > PASS: Servo register test
> > >
> > > PASS: Servo convertor timeout test
> > >
> > > PASS: Interface register test
> > >
> > > PASS: Interface abus test
> > >
> > > PASS: Pps register test
> > >
> > > PASS: Pps interrupt test
> > >
> > > PASS: power logic signals test
> > >
> > > PASS: CBT register test
> > >
> > > PASS: CBT window comp test
> > >
> > > PASS: CBT therm test
> > >
> > > PASS: CBT Cs oven test
> > >
> > > PASS: CBT hw ion test
> > >
> > > PASS: CBT mass spec test
> > >
> > > PASS: CPU RTDS test
> > >
> > > PASS: CPU clock locked test
> > >
> > > PASS: DDFS register test
> > >
> > > PASS: 87MHz PLL test
> > >
> > > PASS: 9.2 GHz PLL test
> > >
> > > PASS: Servo register test
> > >
> > > PASS: Servo convertor timeout test
> > >
> > > PASS: Interface register test
> > >
> > > PASS: Interface abus test
> > >
> > > PASS: Pps register test
> > >
> > > PASS: Pps interrupt test
> > >
> > > PASS: power logic signals test
> > >
> > > PASS: CBT register test
> > >
> > > PASS: CBT window comp test
> > >
> > > PASS: CBT therm test
> > >
> > > PASS: CBT

Re: [time-nuts] 5071A with ATTENTION flashing

[Adrian Godwin]

Yes, I'm sorry about that.

On Wed, Nov 9, 2016 at 5:18 PM, paul swed  wrote:

> Adrian
> I think you may have responded to the wrong thread??
> Regards
> Paul
>
> On Wed, Nov 9, 2016 at 10:21 AM, Adrian Godwin 
> wrote:
>
> > I'm still struggling to get the acrylic I need. I've been into London a
> few
> > times but not been able to get to the shop in business hours. Guess I
> could
> > order online if necessary but it will cost a fair bit more.
> >
> > On Wed, Nov 9, 2016 at 3:19 PM, paul swed  wrote:
> >
> > > I saw the low CBT temp also and 10 degrees C seem like allot. However
> in
> > > the 5060/5061 Frankenstein I run the oven at +10 degrees (approx.) to
> > what
> > > the tube asks for. To drive C fumes out of the oven. A possible
> > assumption
> > > is the cooler oven is emitting fewer C's and the emult is trying to
> make
> > up
> > > for it.
> > >
> > > Li
> > > If it were mine and I checked the other suggestions. I would if
> > convenient
> > > actually attempt to raise the oven temp a bit to see what happens. I
> > would
> > > measure current and use an external supply to match it and then gently
> > > increase the current. But from the thread you do not own it and I
> think a
> > > large amount of money was at stake.
> > >
> > > Regards
> > > Paul
> > > WB8TSL
> > >
> > >
> > > On Wed, Nov 9, 2016 at 7:52 AM, Scott McGrath 
> > wrote:
> > >
> > > > that's telling you that the CBT oven is not up to temp  so you could
> > have
> > > > a failed heater in the tube or the oven controller is malfunctioning
> > > >
> > > > The former well you need a new tube which symmetricom will be happy
> to
> > > > sell you for a 5 figure price tag.
> > > >
> > > > The latter is limited by your repair skills and parts and data
> > > availability
> > > >
> > > > Content by Scott
> > > > Typos by Siri
> > > >
> > > > > On Nov 9, 2016, at 7:42 AM, Li Ang <379...@qq.com> wrote:
> > > > >
> > > > > According to the Log, "CBT Oven Err: -9.55 C" might be something
> > wrong.
> > > > However, I can't find the correct range in the manual. Does anyone
> have
> > > the
> > > > information about this parameter?
> > > > >
> > > > >
> > > > > Regards
> > > > > Li Ang
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > -- Original --
> > > > > From:  "Li Ang";<379...@qq.com>;
> > > > > Date:  Wed, Nov 9, 2016 02:48 PM
> > > > > To:  "Tom Van Baak"; "Discussion of precise
> time
> > > > and frequency measurement";
> > > > >
> > > > > Subject:  Re: [time-nuts] 5071A with ATTENTION flashing
> > > > >
> > > > >
> > > > >
> > > > > Hi Tom
> > > > >
> > > > > I have collected the log from it. Log level is service. The 9.2G
> pll
> > > > pass the test today. The log during the power-up process is also
> > > included.
> > > > >
> > > > >
> > > > > Regards
> > > > >
> > > > > Li Ang / BI7LNQ
> > > > >
> > > > > -
> > > > >
> > > > >
> > > > >
> > > > > scpi >
> > > > >
> > > > > MJD0 02:02:18
> > > > >
> > > > > CBT ID: 3128A00642(H)
> > > > >
> > > > > Status summary: Fatal Error (see Log)
> > > > >
> > > > > Power source: AC
> > > > >
> > > > > Log status: One entry
> > > > >
> > > > >
> > > > > Freq Offset:  0e-15  Osc. control: -9.56 %
> > > > >
> > > > > RF amplitude 1: 6.3 %RF amplitude 2: 6.3 %
> > > > >
> > > > > Zeeman Freq:  39949 Hz   C-field curr:12.213 mA
> > > > >
> > > > > E-multiplier:  2553 VSignal Gain:   14.4 %
> > > > >
> > > > >
> > > > > CBT Oven:   0.0 V   

Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 SoC serial port for ntpd

[Adrian Godwin]

But trailing isn't the same as falling. The leading edge can be of either
polarity.


On Wed, Nov 9, 2016 at 11:28 PM, Bob Stewart  wrote:

> Tom,
> How many times have people posted here, on time-nuts, not to trust the
> trailing edge of a 1PPS pulse?
>
> Bob -
> AE6RV.com
>
> GFS GPSDO list:
> groups.yahoo.com/neo/groups/GFS-GPSDOs/info
>
>   From: Tom Van Baak 
>  To: Discussion of precise time and frequency measurement <
> time-nuts@febo.com>
>  Sent: Wednesday, November 9, 2016 4:44 PM
>  Subject: Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2
> SoC serial port for ntpd
>
> Bob,
>
> The PIC's I use have essentially no jitter. If they generate a 1PPS the
> edge and the pulse width are perfect, down to picoseconds. The talk about
> "other stuff" and "priority" and "number of compares" and "ambiguity" is
> worrisome. It sounds like a design or coding flaw to me, like what happens
> when people try to do precise time with a high level language.
>
> /tvb
>
> - Original Message -
> From: "Bob Stewart" 
> To: "Discussion of precise time and frequency measurement" <
> time-nuts@febo.com>
> Sent: Wednesday, November 09, 2016 9:30 AM
> Subject: Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2
> SoC serial port for ntpd
>
>
> I'd like to comment on the idea of measuring the width of the pulse. My
> experience with creating the 1PPS from an interrupt is that it's fairly
> straightforward how to do the set interrupt: The interrupt happens, you
> execute one, maybe two instructions to raise the output pin, and you leave
> the interrupt routine. But, resetting the pin is a different story. Unless
> you've got a lot of interrupt vectors to play with, the reset part of the
> 1PPS signal is delegated to a general purpose timing interrupt where you're
> doing a lot of other stuff - and it has a somewhat lower priority. So, you
> wind up doing a number of compares to see if you should reset the pin,
> which adds some ambiguity to the set/reset times.
> Granted, I'm doing this on a general purpose PIC, but I have read comments
> about various receivers having some jitter on the reset side of their 1PPS
> pulse.
> Bob
>
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Re: [time-nuts] China Oscillator Alternative

[Adrian Godwin]

I looked at this when it was mentioned here a few weeks ago. I did the
procedure in an hour or so and it's working well, keeping the PPS within
50ns of GPS with 6-8 satellites. Monitored by the patched version of Z38XX
at the moment though I look forward to putting Lady Heather on the job.

The curious thing is, although that file is hosted on eevblog, I can't find
any link to it from the forums. You have to know where to find it.

http://www.eevblog.com/forum/testgear/economical-option-for-precision-frequency-reference/?action=dlattach;attach=172662

Perhaps we could get a copy on Didier's site (with the author, Peter
Garde's permission) before it gets lost ?


On Thu, Nov 10, 2016 at 6:19 PM, Mark Sims  wrote:

> Plus, you can add a Motrorla UT+ GPS receiver into the Z3812A and turn it
> into a GPSDO.   There is a nice writeup of the procedure on EEVBLOG.
> Basically you move a half dozen 0 ohm resistors and add a resistor for the
> antenna current sense circuit.
>
> Also, Lady Heather now talks to them.
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Re: [time-nuts] TCXO drift - related to TVB's posting

[Adrian Godwin]

What if your shop reference were drifting up ?


On Sat, Nov 12, 2016 at 11:25 PM, Joseph Gray  wrote:

> TCXO, not OCXO, but related. Sorry, but I have no graphs.
>
> I work for a municipal radio shop. We service radios that span 20
> years (through acquisitions, it was GE, Ericsson, Com-Net, M/A-COM,
> Tyco, now Harris). There are several different model handhelds and
> mobiles, with different designs and TCXO's. Some are adjusted manualy,
> most via software. I have found that every single TCXO in the various
> model radios drift downward in frequency over time.
>
> One interesting case was a set of radios that sat on the shelf, unused
> for several years. They were issued to some custodians about a year
> ago. I checked all of them on the service monitor beforehand and they
> were well within spec. All of these radios came back to the shop
> recently. They were 1-3 KHz low in transmit frequency. That is an
> unusual amount of drift in one year. Perhaps it has something to do
> with how long they sat on the shelf.
>
> I don't have enough history on our newest radios, so I don't know if
> this downward trend will hold true for them.
>
> Joe Gray
> W5JG
>
>
> On Sat, Nov 12, 2016 at 2:54 PM, Tom Van Baak  wrote:
> > There were postings recently about OCXO ageing, or drift rates.
> >
> > I've been testing a batch of TBolts for a couple of months and it
> provides an interesting set of data from which to make visual answers to
> recent questions. Here are three plots.
> >
> >
> > 1) attached plot: TBolt-10day-fit0-e09.gif (
> http://leapsecond.com/pages/tbolt/TBolt-10day-fit0-e09.gif )
> >
> > A bunch of oscillators are measured with a 20-channel system. Each
> frequency plot is a free-running TBolt (no GPS, no disciplining). The
> X-scale is 10 days and the Y-scale is 1 ppb, or 1e-9 per Y-division. What
> you see at this scale is that all the OCXO are quite stable. Also, some of
> them show drift.
> >
> > For example, the OCXO frequency in channel 14 changes by 2e-9 in 10 days
> for a drift rate of 2e-10/day. It looks large in this plot but its well
> under the typical spec, such as 5e-10/day for a 10811A. We see a variety of
> drift rates, including some that appear to be zero: flat line. At this
> scale, CH13, for example, seems to have no drift.
> >
> > But the drift, when present, appears quite linear. So there are two
> things to do. Zoom in and zoom out.
> >
> >
> > 2) attached plot: TBolt-10day-fit0-e10.gif (
> http://leapsecond.com/pages/tbolt/TBolt-10day-fit0-e10.gif )
> >
> > Here we zoom in by changing the Y-scale to 1e-10 per division. The
> X-scale is still 10 days. Now we can see the drift much better. Also at
> this level we can see instability of each OCXO (or the lab environment). At
> this scale, channels CH10 and CH14 are "off the chart". An OCXO like the
> one in CH01 climbs by 2e-10 over 10 days for a drift rate of 2e-11/day.
> This is 25x better than the 10811A spec. CH13, mentioned above, is not zero
> drift after all, but its drift rate is even lower, close to 1e-11/day.
> >
> > For some oscillators the wiggles in the data (frequency instability) are
> large enough that the drift rate is not clearly measurable.
> >
> > The 10-day plots suggests you would not want to try to measure drift
> rate based on just one day of data.
> >
> > The plots also suggest that drift rate is not a hard constant. Look at
> any of the 20 10-day plots. Your eye will tell you that the daily drift
> rate can change significantly from day to day to day.
> >
> > The plots show that an OCXO doesn't necessarily follow strict rules. In
> a sense they each have their own personality. So one needs to be very
> careful about algorithms that assume any sort of constant or consistent
> behavior.
> >
> >
> > 3) attached plot: TBolt-100day-fit0-e08.gif (
> http://leapsecond.com/pages/tbolt/TBolt-100day-fit0-e08.gif )
> >
> > Here we look at 100 days of data instead of just 10 days. To fit, the
> Y-scale is now 1e-8 per division. Once a month I created a temporary
> thermal event in the lab (the little "speed bumps") which we will ignore
> for now.
> >
> > At this long-term scale, OCXO in CH09 has textbook logarithmic drift.
> Also CH14 and CH16. In fact over 100 days most of them are logarithmic but
> the coefficients vary considerably so it's hard to see this at a common
> scale. Note also the logarithmic curve is vastly more apparent in the first
> few days or weeks of operation, but I don't have that data.
> >
> > In general, any exponential or log or parabolic or circular curve looks
> linear if you're looking close enough. A straight highway may look linear
> but the equator is circular. So most OCXO drift (age) with a logarithmic
> curve and this is visible over long enough measurements. But for shorter
> time spans it will appear linear. Or, more likely, internal and external
> stability issues will dominate and this spoils any linear vs. log
> discussion.
> >
> > So is it linear or log? The answer is it depend

Re: [time-nuts] precision timing pulse

[Adrian Godwin]

Tom describes the PIC as a 'poor man's FPGA'. And I'm aware of how they're
programmed - I agree they're a good choice for this sort of device.

However, even poor men can use FPGAs now. I'm following with interest the
open-source toolchain available for the Lattice ice40,
http://www.clifford.at/icestorm/

There are, of course, other cheap FPGAs and free-to-use vendor tools. I've
always found the vendor tools horrendous, with huge overheads and
complicated licensing, so something a bit more manageable is attractive.


On Thu, Nov 17, 2016 at 10:07 PM, Bob Camp  wrote:

> Hi
>
> There are a number of us on the list who code on ARM MCU’s. Doing the
> same thing on one of them is *not* a trivial undertaking. Making sure that
> it does what it should simply is not worth the effort. The PIC 12 is a low
> cost
> solution and has been extensively tested to show that it does what it
> should
> under a range of conditions ….
>
> Bob
>
>
>
> > On Nov 17, 2016, at 4:26 PM, Bryan _  wrote:
> >
> > Tom:
> >
> >
> > As you were gracious to release the source code for these excellent
> little dividers, I would suspect someone who is somewhat fluent in assembly
> could just modify so it counts a specific number of pulses and then toggles
> a output off. The ARM could be used to restart etc. Although I think the OP
> wanted to know the time taken between a run of a number of cycles.
> >
> >
> > Been playing around with the PD15 to replace 2 -14 pin clock dividers
> and it seems to work like a charm, although I can't seem to find any
> information if the inputs on a 12F675 are Schmitt trigger inputs. Can't
> seem to find anything in the datasheet.
> >
> >
> > -=Bryan=-
> >
> >
> > 
> > From: time-nuts  on behalf of Tom Van Baak
> 
> > Sent: November 16, 2016 3:27 PM
> > To: Discussion of precise time and frequency measurement
> > Subject: Re: [time-nuts] precision timing pulse
> >
> > Chris & Chris,
> >
> > Yes the "TVB dividers" are instruction loops where every cycle is
> counted by hand, and then verified with a simulator, and then checked with
> a time interval counter. All the code is out there at
> www.leapsecond.com/pic/
> >
> >
> > I use PIC's for historical and technical reasons. Modern CPU's and MCU's
> have so many layers of optimization that they are no longer deterministic
> at the cycle level. This makes them worthless for precise time
> applications. In addition many of them use clock edge or PLL tricks to
> increase speed, but this introduces jitter. Or they enable interrupts which
> kills precise timing. The PIC's are old-school, fully synchronous and use
> only one clock edge so the jitter is down at the picosecond level. My code
> is isochronous and doesn't use interrupts for timing. It acts like a poor
> man's FPGA.
> >
> > Arduino probably uses compiled code, external libraries, and interrupts
> so that also is a no-no for precise time. I'm not sure about bare metal
> AVR. I hope someone can do measurements on an AVR divider one day so we can
> compare PIC and AVR jitter. I worry about how AVR implements the clock. So
> this is an open question. But I know how PIC's work so that's what I use.
> BTW, these are "ancient" PIC 12F parts. It's possible modern 16- and 32-bit
> PIC's also go to the dark side and optimize for performance rather than
> picosecond determinism. Another open question.
> >
> > Realize that using a MCU for a frequency divider is a weird niche use of
> the chip, so none of what I say applies if you plan to use any of these as
> a general purpose computing system.
> >
> > Also, we don't know if OP is looking for microsecond, nanosecond, or
> picosecond precision in his timing pulses.
> >
> > /tvb
> >
> > Chris Albertson:
> >> I'm wondering why everyone seems to be assuming a PIC is the right
> >> processor.   Of course it could work for this but I'd select whatever is
> >> the easiest to program and debug.   Those tend to the they little single
> >> board development systems that sell for under $10.  They typically have
> USB
> >> connections to a computer and don't require any specialized equipment to
> >> program.   The Arduino is the prime example of these although I've
> moved to
> >> ARM based uP because they can be less expensive with an order of
> magnitude
> >> better performance and can use the same Arduino IDE and run Arduino
> >> sketches.The PIC is not so beginner friendly and requires some study
> >> before it can be used.But if you as said of course a PIC could work,
> >> this is a pretty simple application
> >
> > Chris Caudle:
> >> You could use AVR (arduino), but once you get to most of the ARM
> >> processors it is harder to make them deterministic because of caches.
> You
> >> want a processor where the number of clocks is constant for all or
> almost
> >> all instructions, and is easy enough that you can code the loops by
> hand.
> >> Code like TVB's divider probably doesn't even use interrupts, 

Re: [time-nuts] 53132 replacement fan

[Adrian Godwin]

This one's pretty quiet. But the airflow is a bit lower.

http://www.frozencpu.com/products/9367/fan-587/Sunon_MagLev-Vapo_40mm_x_20mm_Fan_w_TAC_Sensor_Wire_-_Bare_Wire_HA40201V4--C99.html?tl=c15s560b53&id=mrFX8Rvo

On Mon, Nov 21, 2016 at 5:57 PM, jimlux  wrote:

> On 11/21/16 6:39 AM, Charles Steinmetz wrote:
>
>> Tom wrote:
>>
>> EFB0412MD
>>> Airflow 7.17 CFM
>>> 6300 RPM
>>> Noise 24 dBA
>>>
>>> FBK04F12U
>>> Same exact form factor.
>>> Air Flow 9.2 CFM
>>> 9500 RPM
>>> Noise 42 dB(A)
>>>
>>
>> Note the 18dB greater noise (that's a HUGE difference).  Even with bad
>> bearings in the original fan, it is probably considerably quieter (by
>> 10dB or more) than the proposed replacement.  On the other hand, the
>> replacement moves 28% more air, which may be a good thing.
>>
>>
> That's a 40mm fan, which is a standard size, I'll bet you can find a
> slower turning/quieter fan.
>
>
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Re: [time-nuts] Vintage Quartz Crystal Manufacturing

[Adrian Godwin]

I bought some old crystals on ebay :

http://www.ebay.co.uk/itm/15114483

Is anyone familiar with this style ? I don't think the quartz is visible in
the glass section : I imagine that's just an insulator. I think the quartz
is under a brass disc, with a sping to hold the disc down visible through
the glass.

Does anyone know what the reference marked on them "w'less sets No 7"
refers to ?


On Mon, Sep 26, 2016 at 6:50 AM, Mark Sims  wrote:

> Can you say "Mr Rogers' Neighborhood?"   I knew you could...
>
> He (along with creepy Mr McFeelie) always ran segments on how some item
> was made.   Geared towards pre-schoolers, but always worth watching.
>
> -
>
> Compare the Science channel's new "How Do They Do It" to the older "How
> It's Made"
> shows.
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Re: [time-nuts] Vintage Quartz Crystal Manufacturing

[Adrian Godwin]

The markings are actually 3720 k/cs, 3760 k/cs and 3780 k/cs. And I think
it's probably for the wireless No 7 shown in http://www.wftw.nl/wsets.html.
But you could be right - they may not be crystals.

As for ebay .. yes, buyer beware. Though in this case I know the seller
personally and while he might be mistaken, he won't be intentionally
misleading.


On Sat, Nov 26, 2016 at 3:15 PM, Bob Camp  wrote:

> Hi
>
> Welcome to eBay …..
>
> I don’t believe those are crystals at all. If you take a look at the
> markings on the parts
> they are labeled “80 K cps”. In other words they are 80 KHz not 80M
> devices. Looking
> at the gap, if there is a crystal in there it’s not obvious that it’s big
> enough for 80 KHz.
>
> My guess is that they are tank tuning caps for an mechanical MOPA style
> transmitter.
> The size and construction are about right for that sort of thing. Swap one
> in and the
> transmit frequency changes. Number 7 for 80 KHz. Number 8 for 85 KHz.
> Number 7 for
> 75 KHz. Just a guess …
>
> Bob
>
>
>
> > On Nov 26, 2016, at 7:40 AM, Adrian Godwin  wrote:
> >
> > I bought some old crystals on ebay :
> >
> > http://www.ebay.co.uk/itm/15114483
> >
> > Is anyone familiar with this style ? I don't think the quartz is visible
> in
> > the glass section : I imagine that's just an insulator. I think the
> quartz
> > is under a brass disc, with a sping to hold the disc down visible through
> > the glass.
> >
> > Does anyone know what the reference marked on them "w'less sets No 7"
> > refers to ?
> >
> >
> > On Mon, Sep 26, 2016 at 6:50 AM, Mark Sims  wrote:
> >
> >> Can you say "Mr Rogers' Neighborhood?"   I knew you could...
> >>
> >> He (along with creepy Mr McFeelie) always ran segments on how some item
> >> was made.   Geared towards pre-schoolers, but always worth watching.
> >>
> >> -
> >>
> >> Compare the Science channel's new "How Do They Do It" to the older "How
> >> It's Made"
> >> shows.
> >> ___
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> >> and follow the instructions there.
> >>
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Re: [time-nuts] RPi/ beagle bone-like computer without video

[Adrian Godwin]

The tiny g3 routers are worth looking at. They have WiFi, Ethernet and USB,
cost very little and will usually run wrt54g Linux. Can be rather short on
memory though.

On 30 Nov 2016 8:43 p.m., "jimlux"  wrote:

> I'm looking for a small linux single board - similar to RPi or Beaglebone
> Black, but don't need the HDMI, or video stuff.
> Preferably without weird connectors, and available for wide temperature
> ranges (it's for a data logger/collector in the field)
>
> What's out there?
>
> There's BBB in industrial flavor (-40 to +85C ) for $60-70
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Re: [time-nuts] Switching regulator replacement for 7805

[Adrian Godwin]

Thanks for this. I've seen something similar from Murata :

http://uk.farnell.com/murata-power-solutions/oki-78sr-5-1-5-w36-c/converter-dc-dc-1-o-p-7-5w-1-5a/dp/2102101

Since they're a mainstream supplier of inductors they may have managed
better performance - it would be interesting to compare.


On Sun, Dec 4, 2016 at 6:50 PM, John Ackermann N8UR  wrote:

> I found a cute little switching regulator that's a drop-in replacement for
> an LM7805: http://www.ebay.com/itm/261243604047
>
> I got a couple to play with, mainly to see how bad the noise would be.
> Here are spectrum analyzer and PN shots comparing a cheap surplus OCXO when
> driven by a regular 7805 and by the switching replacement.
>
> The switching frequency is supposed to be 2 MHz but you can see that it's
> more like 2.4 MHz.  Whether this performance is sufficient for any
> application is up to you.  It sure runs a lot cooler than a 7805, though!
>
> John
>
>
>
>
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Re: [time-nuts] Switching regulator replacement for 7805

[Adrian Godwin]

At Farnell, they're listed under Power Supplies rather than Switching
Regulators (which is a subdivision of Semiconductors).

It makes sense since one is a board product and the other a chip, but when
the board product is a drop-in replacement for a TO220, less sense!


On Sun, Dec 4, 2016 at 7:44 PM, John Ackermann N8UR  wrote:

> And Digikey does stock the Murata part, for about $4.30.  Why I couldn't
> find it when searching their site for switching regulators, I don't know.
>
> John
> 
>
>
> On 12/04/2016 02:39 PM, John Ackermann N8UR wrote:
>
>> Thanks for that pointer!  When I searched Digikey, I wasn't able to find
>> anything that was in the 3-lead TO-220 case.  I will definitely check
>> out the Murata units, as I suspect they perform better than this one.
>>
>> John
>> 
>> On 12/04/2016 02:01 PM, Adrian Godwin wrote:
>>
>>> Thanks for this. I've seen something similar from Murata :
>>>
>>> http://uk.farnell.com/murata-power-solutions/oki-78sr-5-1-5-
>>> w36-c/converter-dc-dc-1-o-p-7-5w-1-5a/dp/2102101
>>>
>>>
>>> Since they're a mainstream supplier of inductors they may have managed
>>> better performance - it would be interesting to compare.
>>>
>>>
>>> On Sun, Dec 4, 2016 at 6:50 PM, John Ackermann N8UR 
>>> wrote:
>>>
>>> I found a cute little switching regulator that's a drop-in
>>>> replacement for
>>>> an LM7805: http://www.ebay.com/itm/261243604047
>>>>
>>>> I got a couple to play with, mainly to see how bad the noise would be.
>>>> Here are spectrum analyzer and PN shots comparing a cheap surplus
>>>> OCXO when
>>>> driven by a regular 7805 and by the switching replacement.
>>>>
>>>> The switching frequency is supposed to be 2 MHz but you can see that
>>>> it's
>>>> more like 2.4 MHz.  Whether this performance is sufficient for any
>>>> application is up to you.  It sure runs a lot cooler than a 7805,
>>>> though!
>>>>
>>>> John
>>>>
>>>>
>>>>
>>>>
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Re: [time-nuts] Lady Heather Version 5 is now available

[Adrian Godwin]

Now running for me on Linux twice : one with a KS24361 and the other with a
Res-T (rx only).

Thanks !


On Sat, Dec 10, 2016 at 7:09 PM, Bob Camp  wrote:

> Hi
>
> Well there goes the neighborhood :) …
>
> It used to be that the absolutely terrific Lady Heather only worked on
> TBolt’s.
> That made the TBolt a slam dunk when it came to recommending a GPSDO.
> Now that it’s even more terrific (THANKS !!!), and no longer is TBolt
> only, do I
> dump all my TBolts ? :)
>
> Bob
>
> > On Dec 10, 2016, at 2:04 PM, paul swed  wrote:
> >
> > To everyone that has made this release available. Thank you ever so much.
> > What a Holiday present. Can't wait to get it going on the z3801. Yah.
> > But I can also see a raspberry pi very quickly just for fun.
> > Regards
> > Paul
> > WB8TSL
> >
> > On Sat, Dec 10, 2016 at 12:31 PM, Tim Lister 
> wrote:
> >
> >> On Sat, Dec 10, 2016 at 9:21 AM,   wrote:
> >>> Thanks for the new version of Lady Heather!  I have already downloaded,
> >> compiled it and it is running well on my linux box, but I did have one
> >> minor problem.
> >>> I am running Fedora 24 (have not upgraded my Time/Radio PC to Fedora 25
> >> yet) and followed the readme instruction:
> >>>
> >>> For Fedora Linux edit the makefile and change "OS = g++" to "OS = gpp".
> >>>
> >>> but making this edit did not work for me (could not find gpp).   I had
> >> to change it back to g++ and it compiled without errors.
> >>
> >> Built out of the box/zipfile for me on Fedora 24 with the stock
> >> makefile unaltered. Running fine with my UCCM GPSDO from China. Now
> >> all I need is Santa to bring me an antenna installer's time to get a
> >> better outdoor antenna location...
> >>
> >>>
> >>> Thanks again for this great program!
> >>
> >> Yes, my thanks also to Mark for the wonderful program - I shall look
> >> forward to watching the leap second on it at the end of this year.
> >>
> >>>
> >>> 73,
> >>> Brian
> >>> KD4UYP
> >>>
> >>
> >> Tim
> >> ___
> >> time-nuts mailing list -- time-nuts@febo.com
> >> To unsubscribe, go to https://www.febo.com/cgi-bin/
> >> mailman/listinfo/time-nuts
> >> and follow the instructions there.
> >>
> > ___
> > time-nuts mailing list -- time-nuts@febo.com
> > To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> > and follow the instructions there.
>
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Re: [time-nuts] Next upgrade

[Adrian Godwin]

I've got several of the Ref 0 boxes but none of the Ref 1. I've added an
Oncore GPS receiver to one of them as per Peter Garde's notes and it works
well.

But I'd like it to run with an unmodified Ref 0 too in the ref0/ref1
configuration. Not that I need an HA reference but just for interest. I've
only had a quick look so far and found that connecting the two together
with a 15-pin cable didn't work.

Has anyone looked into this ?


On Wed, Nov 22, 2017 at 11:01 PM, Bob kb8tq  wrote:

> Hi
>
>
>
> > On Nov 22, 2017, at 5:16 PM, Jerry Hancock  wrote:
> >
> > Three questions:
> >
> > 1) Now that I’ve split my Lucent RFTG-U into a REF0 and REF1 unit with
> both supplying 10Mhz and 1PPS, is there a way to combine the outputs or
> some other technique to improve the short and/or long term performance?
>
> You can monitor one against the other. Ideally you would want three
> GPSDO’s and a
> monitoring setup. That way you can figure out which of the three has gone
> bad.
>
> >
> > 2) I’ve become interested in Rubidium Disciplined Oscillators recently
> and was now thinking of purchasing one of the PRS-10 that I see on Ebay. If
> I did that and replaced one of the DOCXOs from one of the Lucent boxes,
> what impact would this have on the overall performance both with and
> without (when in hold-over)?
>
> If you go into holdover, you are the exception. Most setups rarely go into
> holdover. When they
> do, it’s because a hurricane just went over the house. Generally that’s
> not when the focus is going
> to be on timing experiments.
>
> > Basically, is it worth the money to upgrade one of the boxes to a
> Rubidium disciplined oscillator assuming the GPS signal is rarely lost?
>
> Not worth the money if you are only looking at holdover and have a typical
> setup.
>
> >
> > 3) Figuring the PRS-10 will cost around $250 when all is said and done,
> is there a better option to improve my GPSDO system?
>
>
> Disciplining implies continuously correcting. Rb standards age much less
> than a typical
> OCXO. Oddly enough their temperature stability may not be as good as a
> high end
> DOCXO. It is fairly common to try to stabilize the environment your
> standards operate in.
> To the extent you are successful this reduces the need to deal with
> temperature.
>
> The net effect is that disciplining an Rb at a rate (filter / control loop
> / manual tweak) of less than
> a few days actually makes the Rb worse. Coming up with software to “back
> off” on the tuning is
> not as simple as it might seem.
>
> This comes back to the fact that the GPS signal (or any of the sat
> signals) are quite noisy. You
> need to average them over a *long* time to get good performance. Rb’s are
> enough better than
> a GPSDO OCXO that the time ranges really stretch out ….
>
> >
> > I basically use the GPSDO as a reference for any equipment that takes an
> input. I have no monetary need for a reference, just an interest.
>
> For most normal test equipment, a GPSDO output is “plenty good enough”. As
> a source for fancy
> timing experiments … maybe not so much. As a phase noise reference or a
> spur free source for
> microwave games … also not the best way to go.
>
> Bob
>
>
> >
> > Thanks.
> >
> > Jerry
> >
> > ___
> > time-nuts mailing list -- time-nuts@febo.com
> > To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> > and follow the instructions there.
>
> ___
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> mailman/listinfo/time-nuts
> and follow the instructions there.
>
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Re: [time-nuts] Next upgrade

[Adrian Godwin]

Yes, I cross-connected  the pins, but I didn't cut any short.



On Wed, Nov 22, 2017 at 11:36 PM, Bob kb8tq  wrote:

> Hi
>
> I have run a number of the REF0 / REF1 combos. They all seem to work fine.
> The standard cable has some odd short pins on it. If you are not hot
> plugging
> the cable I don’t think they matter at all. If anything, the system is
> more reliable
> with a normal length pin on the connector.
>
> Bob
>
> > On Nov 22, 2017, at 6:08 PM, Adrian Godwin  wrote:
> >
> > I've got several of the Ref 0 boxes but none of the Ref 1. I've added an
> > Oncore GPS receiver to one of them as per Peter Garde's notes and it
> works
> > well.
> >
> > But I'd like it to run with an unmodified Ref 0 too in the ref0/ref1
> > configuration. Not that I need an HA reference but just for interest.
> I've
> > only had a quick look so far and found that connecting the two together
> > with a 15-pin cable didn't work.
> >
> > Has anyone looked into this ?
> >
> >
> > On Wed, Nov 22, 2017 at 11:01 PM, Bob kb8tq  wrote:
> >
> >> Hi
> >>
> >>
> >>
> >>> On Nov 22, 2017, at 5:16 PM, Jerry Hancock  wrote:
> >>>
> >>> Three questions:
> >>>
> >>> 1) Now that I’ve split my Lucent RFTG-U into a REF0 and REF1 unit with
> >> both supplying 10Mhz and 1PPS, is there a way to combine the outputs or
> >> some other technique to improve the short and/or long term performance?
> >>
> >> You can monitor one against the other. Ideally you would want three
> >> GPSDO’s and a
> >> monitoring setup. That way you can figure out which of the three has
> gone
> >> bad.
> >>
> >>>
> >>> 2) I’ve become interested in Rubidium Disciplined Oscillators recently
> >> and was now thinking of purchasing one of the PRS-10 that I see on
> Ebay. If
> >> I did that and replaced one of the DOCXOs from one of the Lucent boxes,
> >> what impact would this have on the overall performance both with and
> >> without (when in hold-over)?
> >>
> >> If you go into holdover, you are the exception. Most setups rarely go
> into
> >> holdover. When they
> >> do, it’s because a hurricane just went over the house. Generally that’s
> >> not when the focus is going
> >> to be on timing experiments.
> >>
> >>> Basically, is it worth the money to upgrade one of the boxes to a
> >> Rubidium disciplined oscillator assuming the GPS signal is rarely lost?
> >>
> >> Not worth the money if you are only looking at holdover and have a
> typical
> >> setup.
> >>
> >>>
> >>> 3) Figuring the PRS-10 will cost around $250 when all is said and done,
> >> is there a better option to improve my GPSDO system?
> >>
> >>
> >> Disciplining implies continuously correcting. Rb standards age much less
> >> than a typical
> >> OCXO. Oddly enough their temperature stability may not be as good as a
> >> high end
> >> DOCXO. It is fairly common to try to stabilize the environment your
> >> standards operate in.
> >> To the extent you are successful this reduces the need to deal with
> >> temperature.
> >>
> >> The net effect is that disciplining an Rb at a rate (filter / control
> loop
> >> / manual tweak) of less than
> >> a few days actually makes the Rb worse. Coming up with software to “back
> >> off” on the tuning is
> >> not as simple as it might seem.
> >>
> >> This comes back to the fact that the GPS signal (or any of the sat
> >> signals) are quite noisy. You
> >> need to average them over a *long* time to get good performance. Rb’s
> are
> >> enough better than
> >> a GPSDO OCXO that the time ranges really stretch out ….
> >>
> >>>
> >>> I basically use the GPSDO as a reference for any equipment that takes
> an
> >> input. I have no monetary need for a reference, just an interest.
> >>
> >> For most normal test equipment, a GPSDO output is “plenty good enough”.
> As
> >> a source for fancy
> >> timing experiments … maybe not so much. As a phase noise reference or a
> >> spur free source for
> >> microwave games … also not the best way to go.
> >>
> >> Bob
> >>
> >>
> >>>
> >>> Thanks.
> >>>
> >>> Jerry
> >>>
> >>> __

Re: [time-nuts] Next upgrade

[Adrian Godwin]

Turns out is does work - Initially, when I linked them, both boxes had the
standby light go out and the unmodified ref-0 (with no GPS receiver) showed
Fault and No GPS.

So I assumed there was some problem that might be causing them to conflict
over the interface, and unplugged it.

I've tried it again with more patience and after 10 minutes or so, the
modified ref0 goes into standby and the one without a receiver has only the
green ON light.  I guess that's working correctly :)



On Thu, Nov 23, 2017 at 12:23 AM, Jerry Hancock  wrote:

> Adrian, when you stated it didn’t work, what were the results?
>
> I had mine running in HA mode, if you can call it that, because only one
> has a GPS.  Actually now that I think about it, the separate but modified
> REF0 and modified REF1, assuming separate power and antennas, is probably
> closer to HA than the original application.  I have both mine running now
> with Lady Heather tracking each and I’ve been playing around with
> comparisons.  Now in my case, if either goes down for any reason the other
> can take over.  I guess in order to make them truly HA, we would need a
> diode or relay switched transfer to the active unit.
>
> Jerry
>
> > On Nov 22, 2017, at 4:10 PM, Adrian Godwin  wrote:
> >
> > Yes, I cross-connected  the pins, but I didn't cut any short.
> >
> >
> >
> > On Wed, Nov 22, 2017 at 11:36 PM, Bob kb8tq  wrote:
> >
> >> Hi
> >>
> >> I have run a number of the REF0 / REF1 combos. They all seem to work
> fine.
> >> The standard cable has some odd short pins on it. If you are not hot
> >> plugging
> >> the cable I don’t think they matter at all. If anything, the system is
> >> more reliable
> >> with a normal length pin on the connector.
> >>
> >> Bob
> >>
> >>> On Nov 22, 2017, at 6:08 PM, Adrian Godwin 
> wrote:
> >>>
> >>> I've got several of the Ref 0 boxes but none of the Ref 1. I've added
> an
> >>> Oncore GPS receiver to one of them as per Peter Garde's notes and it
> >> works
> >>> well.
> >>>
> >>> But I'd like it to run with an unmodified Ref 0 too in the ref0/ref1
> >>> configuration. Not that I need an HA reference but just for interest.
> >> I've
> >>> only had a quick look so far and found that connecting the two together
> >>> with a 15-pin cable didn't work.
> >>>
> >>> Has anyone looked into this ?
> >>>
> >>>
> >>> On Wed, Nov 22, 2017 at 11:01 PM, Bob kb8tq  wrote:
> >>>
> >>>> Hi
> >>>>
> >>>>
> >>>>
> >>>>> On Nov 22, 2017, at 5:16 PM, Jerry Hancock  wrote:
> >>>>>
> >>>>> Three questions:
> >>>>>
> >>>>> 1) Now that I’ve split my Lucent RFTG-U into a REF0 and REF1 unit
> with
> >>>> both supplying 10Mhz and 1PPS, is there a way to combine the outputs
> or
> >>>> some other technique to improve the short and/or long term
> performance?
> >>>>
> >>>> You can monitor one against the other. Ideally you would want three
> >>>> GPSDO’s and a
> >>>> monitoring setup. That way you can figure out which of the three has
> >> gone
> >>>> bad.
> >>>>
> >>>>>
> >>>>> 2) I’ve become interested in Rubidium Disciplined Oscillators
> recently
> >>>> and was now thinking of purchasing one of the PRS-10 that I see on
> >> Ebay. If
> >>>> I did that and replaced one of the DOCXOs from one of the Lucent
> boxes,
> >>>> what impact would this have on the overall performance both with and
> >>>> without (when in hold-over)?
> >>>>
> >>>> If you go into holdover, you are the exception. Most setups rarely go
> >> into
> >>>> holdover. When they
> >>>> do, it’s because a hurricane just went over the house. Generally
> that’s
> >>>> not when the focus is going
> >>>> to be on timing experiments.
> >>>>
> >>>>> Basically, is it worth the money to upgrade one of the boxes to a
> >>>> Rubidium disciplined oscillator assuming the GPS signal is rarely
> lost?
> >>>>
> >>>> Not worth the money if you are only looking at holdover and have a
> >> typical
> >>>> setup.
> >>>>
> >>>>>
> &g

Re: [time-nuts] Simple open source microcontroller solution to tune DDS needed

[Adrian Godwin]

Maybe this one ?

http://www.qsl.net/pa3ckr/bascom%20and%20avr/ad9951/index.html

There are probably many others


On Wed, Dec 13, 2017 at 8:03 PM, Richard (Rick) Karlquist <
rich...@karlquist.com> wrote:

> I need a very simple controller to tune a DDS with up/down
> switches (imagine setting the time on a clock).  A DDS
> chip, such as an AD9836 would go on a PC board and a couple
> of pushbuttons would tell the controller to tune up or
> down.
>
> Before reinventing this wheel, I thought I would see if
> anyone knows of a similar solution that can be leveraged.
> What I would like is both hardware and software, where
> the software could be edited to accommodate the up/down
> buttons.  A last resort would be to write software from
> scratch.  My software skills are extremely limited.
> Cutting and pasting code might work for me.
>
> I need to be able to embed this onto an existing PC board.
> I can't use a preexisting "daughter" card, other than
> to copy the design of the card.
>
> Rick Karlquist
> N6RK
>
>
>
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Re: [time-nuts] Simple open source microcontroller solution to tune DDS needed

[Adrian Godwin]

It's a bit bizarre that it uses Basic. I just remember my local ARC using
it as a project sometime ago. Possibly in the 20th century. :)


On Wed, Dec 13, 2017 at 9:03 PM, Richard (Rick) Karlquist <
rich...@karlquist.com> wrote:

> This looks like a very good starting point.  It's a superset
> that I can just simplify.
>
> Rick
>
>
> On 12/13/2017 12:10 PM, Adrian Godwin wrote:
>
>> Maybe this one ?
>>
>> http://www.qsl.net/pa3ckr/bascom%20and%20avr/ad9951/index.html
>>
>> There are probably many others
>>
>>
>> On Wed, Dec 13, 2017 at 8:03 PM, Richard (Rick) Karlquist <
>> rich...@karlquist.com> wrote:
>>
>> I need a very simple controller to tune a DDS with up/down
>>> switches (imagine setting the time on a clock).  A DDS
>>> chip, such as an AD9836 would go on a PC board and a couple
>>> of pushbuttons would tell the controller to tune up or
>>> down.
>>>
>>> Before reinventing this wheel, I thought I would see if
>>> anyone knows of a similar solution that can be leveraged.
>>> What I would like is both hardware and software, where
>>> the software could be edited to accommodate the up/down
>>> buttons.  A last resort would be to write software from
>>> scratch.  My software skills are extremely limited.
>>> Cutting and pasting code might work for me.
>>>
>>> I need to be able to embed this onto an existing PC board.
>>> I can't use a preexisting "daughter" card, other than
>>> to copy the design of the card.
>>>
>>> Rick Karlquist
>>> N6RK
>>>
>>>
>>>
>>> ___
>>> time-nuts mailing list -- time-nuts@febo.com
>>> To unsubscribe, go to https://www.febo.com/cgi-bin/m
>>> ailman/listinfo/time-nuts
>>> and follow the instructions there.
>>>
>>> ___
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>> ailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>>
>>
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Re: [time-nuts] Simple open source microcontroller solution to tune DDS needed

[Adrian Godwin]

Arduino is, of course (or actually some slightly weird dialect of C++).
But the pa3ckr code at
http://www.qsl.net/pa3ckr/bascom%20and%20avr/ad9951/ad9951-12.bas is in
bascom, whatever that is.

On Wed, Dec 13, 2017 at 9:12 PM, paul swed  wrote:

> Must have missed something here. Basic? Arduino uses C behaviors. God knows
> everythings been written for it so maybe there is a basic language. That
> said schematics are readily available and I believe its all open source.
> Thats why its been so popular. Lots of nice simple tools for it also.
> Regards
> Paul
> WB8TSL
>
> On Wed, Dec 13, 2017 at 4:05 PM, Adrian Godwin 
> wrote:
>
> > It's a bit bizarre that it uses Basic. I just remember my local ARC using
> > it as a project sometime ago. Possibly in the 20th century. :)
> >
> >
> > On Wed, Dec 13, 2017 at 9:03 PM, Richard (Rick) Karlquist <
> > rich...@karlquist.com> wrote:
> >
> > > This looks like a very good starting point.  It's a superset
> > > that I can just simplify.
> > >
> > > Rick
> > >
> > >
> > > On 12/13/2017 12:10 PM, Adrian Godwin wrote:
> > >
> > >> Maybe this one ?
> > >>
> > >> http://www.qsl.net/pa3ckr/bascom%20and%20avr/ad9951/index.html
> > >>
> > >> There are probably many others
> > >>
> > >>
> > >> On Wed, Dec 13, 2017 at 8:03 PM, Richard (Rick) Karlquist <
> > >> rich...@karlquist.com> wrote:
> > >>
> > >> I need a very simple controller to tune a DDS with up/down
> > >>> switches (imagine setting the time on a clock).  A DDS
> > >>> chip, such as an AD9836 would go on a PC board and a couple
> > >>> of pushbuttons would tell the controller to tune up or
> > >>> down.
> > >>>
> > >>> Before reinventing this wheel, I thought I would see if
> > >>> anyone knows of a similar solution that can be leveraged.
> > >>> What I would like is both hardware and software, where
> > >>> the software could be edited to accommodate the up/down
> > >>> buttons.  A last resort would be to write software from
> > >>> scratch.  My software skills are extremely limited.
> > >>> Cutting and pasting code might work for me.
> > >>>
> > >>> I need to be able to embed this onto an existing PC board.
> > >>> I can't use a preexisting "daughter" card, other than
> > >>> to copy the design of the card.
> > >>>
> > >>> Rick Karlquist
> > >>> N6RK
> > >>>
> > >>>
> > >>>
> > >>> ___
> > >>> time-nuts mailing list -- time-nuts@febo.com
> > >>> To unsubscribe, go to https://www.febo.com/cgi-bin/m
> > >>> ailman/listinfo/time-nuts
> > >>> and follow the instructions there.
> > >>>
> > >>> ___
> > >> time-nuts mailing list -- time-nuts@febo.com
> > >> To unsubscribe, go to https://www.febo.com/cgi-bin/m
> > >> ailman/listinfo/time-nuts
> > >> and follow the instructions there.
> > >>
> > >>
> > >>
> > ___
> > time-nuts mailing list -- time-nuts@febo.com
> > To unsubscribe, go to https://www.febo.com/cgi-bin/
> > mailman/listinfo/time-nuts
> > and follow the instructions there.
> >
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[time-nuts] Vectron oscillator teardown

[Adrian Godwin]

https://www.youtube.com/watch?v=oMcRUqhrYNY

Right at the end of this teardown (50:50 minutes) Mike reaches the Vectron
oscillator module and opens that up too.
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Re: [time-nuts] Oscilloquartz OSA-4350 GPSDO

[Adrian Godwin]

A similar product is the Polar Toneohm. I've been after one for a while but
they seem to go for high prices.



On Mon, Jan 1, 2018 at 12:12 AM, Gary Woods 
wrote:

> On Sun, 31 Dec 2017 20:56:26 +0100, you wrote:
>
> > Without a thermal camera I've used a 4-1/2 digit DVM set for 200mV full
> scale, or 20mV if you can do that. Often the low uV resolution will allow
> you to trace the current path, just start at the power and ground inputs to
> the board and follow the voltage drops to the short. Or go old-school with
> an HP logic pulser and current probe...
> OK, I think, made an audible low-ohm probe "Shortsqueak?"  That can
> resolve an inch or less of PC board trace.  You can't have mine!
>
>
> ---
> This email has been checked for viruses by AVG.
> http://www.avg.com
>
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Re: [time-nuts] LED replacement screen for 53131A 53132A!!??

[Adrian Godwin]

Like this one ?
(Not for a 53132A but a similar problem)

Better still would be a graphics display that emulates the original
annunciators.

https://www.youtube.com/watch?v=GgQS7ePEFmA



On Sat, Jan 6, 2018 at 9:14 PM,  wrote:

> Hi,
>
> Saw this on the EEVblog and wondered if it could be done for the 53132A??
>
> https://www.eevblog.com/forum/projects/led-display-for-hp-3457a-multimete
> r-i-did-it-)/
>
> I'd just be happy with 7 segment hi efficiency LEDs and just a few of the
> annunciators!!
>
> Cheers,
>
> Corby
>
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Re: [time-nuts] PBS, Tue evening, The Secret of Tuxedo Park

[Adrian Godwin]

Joe's link worked for me earlier this afternoon in the UK, but is blocked
now at 10pm local time.
Glad I watched it when I could !


On Wed, Jan 17, 2018 at 10:00 PM, Bill Metzenthen 
wrote:

> It also worked in Australia last night.  I watched a few minutes and
> decided to watch the rest today.  Unfortunately, it is now geo-blocked :-(
> It's also blocked on the PBS site.
>
>
>
> On 18/01/18 02:09, Heinz Breuer wrote:
>
>> The link worked perfectly in Germany.
>>
>> vy 73 Heinz DH2FA, KM5VT
>>
>> Von meinem iPhone gesendet
>>
>> Am 17.01.2018 um 15:48 schrieb EB4APL :
>>>
>>> Joe,
>>> Thank you for the pointer. The regular web site don't allow the series
>>> to be viewed outside USA.
>>>
>>> 73 de Ignacio, EB4APL
>>>
>>>
>>> El 17/01/2018 a las 2:47, Joseph Gray escribió:
 If you want to watch this episode online, go here:
 http://video.unctv.org/video/3008204310

 This is the UNC Public TV web site.

 Joe Gray
 W5JG



 On Tue, Jan 16, 2018 at 2:28 PM, Bill Tracey  wrote:
>
> To record OTA television I use an HDHomeRun :
> https://www.silicondust.com/hdhomerun/
>
> I'll grab tonight's run of The Secret of Tuxedo Park
>
> Cheers,
>
> Bill
>
> At 09:04 AM 1/16/2018, you wrote:
>
> I can't stress enough how important Loomis was to the history of
>> precise
>> timekeeping in early radio, telephone, pendulum clock, quartz
>> oscillator
>> era. And for those of us who still have Loran-C receivers can thank
>> him
>> (Loomis Radio Navigation -> LRN -> Loran).
>> .
>>
>> If someone knows how to record any time/clock/navigation parts of PBS
>> show for non-US viewers let me know, off-list.
>>
>> /tvb
>>
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>>
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Re: [time-nuts] GPS Jamming

[Adrian Godwin]

What a pity nobody thought to include an accuracy degradation system into
GPS itself, for use when you don't want the enemy to benefit from it.

And how odd to show off your secret jamming technology in a major scheduled
exercise, so the Bad Guys can study it.


On Fri, Jan 26, 2018 at 2:57 PM, Gary Neilson  wrote:

> Don't know if this has be posted before or not. Also don't know if this
> will affect timing info.
>
> GPS Jamming  gps-in-the-western-u-s-for-largest-ever-red-flag-air-war-exercise>
>
> I am on the very edge of their coverage map.
>
> Gary
>
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Re: [time-nuts] Receiving the MSF time signal on cheap radio modules

[Adrian Godwin]

Hi Deirdre,

I'd like to repeat your measurement at a different location (eastern
england).

What did you use to capture the data and write it as a vcd file ?

-adrian


On Tue, Feb 6, 2018 at 6:40 PM, Deirdre O'Byrne 
wrote:

> OK so it's not the microsecond or nanosecond stuff that much of this list
> is about, but I've been running an experiment for the past few days
> gathering data on how well (or otherwise) a pair of cheap EM2S radio
> receiver modules receive the MSF radio signal. I've been trying to see if I
> could design a decoding algorithm that would be more noise-tolerant than
> the algorithms I've seen out in the wild.
>
> Details are on my github, and the results are presented in a paper -
>
> https://github.com/deirdreobyrne/MSF-EM2S/blob/master/paper.pdf
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Re: [time-nuts] Symmetricom 58532A GPS Antenna : Launch3 Surplus

[Adrian Godwin]

It's called 'adhesive lined heatshrink'. Yes, it's available, though a reel
of the Good Stuff (Raychem) costs a small fortune.
They also make custom boots to fit various standard connectors.

Probably best bought as surplus or from a trusted seller who bought reels
from military, autosport or aircraft industries. The short lengths
available on ebay are often inferior grades. A heatshrinking tape is also
available.

Hams tend to use self-amalgamating tape, as Phil recommended.

On Sat, Feb 10, 2018 at 12:41 AM, Hal Murray 
wrote:

>
> li...@philpem.me.uk said:
> > Generally speaking, you can seal most RF connectors quite nicely with a
> few
> > layers of self-amalgamating tape and a layer of PVC tape over the top of
> > that (to protect from UV).
>
> Many years ago, I picked up a chunk of scrap the local cable TV installer
> had
> left on the ground underneath the utility pole out in front of my house.
> It
> was a chunk of industrial strength shrink wrap with a layer of goop on the
> inside.
>
> Is that stuff available in small quantities?  Would the antenna withstand
> the
> necessary heat?
>
> How do hams seal antenna connectors?
>
>
> --
> These are my opinions.  I hate spam.
>
>
>
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[time-nuts] Sigtec GPS receiver

[Adrian Godwin]

I've come across an old (2003) GPS receiver made by the Australian company
Sigtec Navigation. Although this is old, it has some interest because it's
a relatively open design and has been used as the basis for various open
source and experimental receivers.

It does seem to work (I'm getting NMEA out of it and it just jumped from an
old location to one very close to me) but I haven't been able to find any
manufacturer information on it - just lots of references to it being used
with different firmware.

The company themselves have apparently gone bust.

Does anyone have any more details ?

-adrian
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