[time-nuts] Re: Win 10 stuff
Thanks for that info (below) about Win 10 turning off auto updates. I think I got gpedit installed on my Win 10 Home and have made these changes. Nice. Does anyone know if there is a way to get Win 10 to stop nagging me about creating/fixing a Microsoft account? -- "Microsoft account problem -- we need to fix..." I don't want an account. To paraphrase an old movie -- Accounts... we ain't got no accounts. We don't need no stinking accounts. BTW My one Win 10 PC is dual boot with Linux Mint. On 4/14/2021 12:10 PM, shouldbe q931 wrote: To disable Windows Updates on a workgroup Windows. Start > Run > gpedit.msc Computer Configuration > Administrative Templates > Windows Components Windows Update Open Configure Automatic Updates Select Disabled, then OK to close To block feature releases (1803/1909/20h4 etc.) requires editing the registry directly. Other methods to prevent Windows Updates include running on an isolated VLAN/Subnet etc. I would however suggest that three raspberry Pi4 each with GPS/GPSDO using PPS over GPIO would consume less power, and have greater overall stability. Cheers On Wed, Apr 14, 2021 at 4:47 PM paul swed wrote: Several comments along this line. I have also attempted a number of ways to stop the enforced reboots and upgrades in win 10. I do know win 10 embedded/IOT does allow you to shut upgrades off. But getting an embedded license seems challenging in 1 or 2 units. As far as I can tell embedded is pretty much full win 10 with a bit more control. But all that said this threads has been really good with respect to a small ntp server for the home. Almost enough to twist my arm into a linux implementation. Regards Paul WB8TSL On Wed, Apr 14, 2021 at 11:28 AM Russ Ramirez wrote: Hi Kevin, I tried this (am a Consultant) but on Windows 10 Enterprise, and it had no effect. That's OK though because I am sick of the cr@p MS and other companies are pulling with these platforms (even though it feeds me:-). I'll be implementing the PPS guidance that Canonical has documented for 20.04 tonight. Russ Message: 5 Date: Tue, 13 Apr 2021 17:28:53 + From: Kevin Schuchmann Subject: [time-nuts] Re: Replacement of Windows NTP server with Linux To: Discussion of precise time and frequency measurement Message-ID: protonmail.com Content-Type: text/plain; charset=utf-8 Russ, You could have also just run gpedit.msc (group policy editor) to turn off the updates/reboots in windows 10. It comes standard on pro but can be added to home also I believe. Kevin ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: RE - before time was invented (Jan Boutsen)
The image file was .png not .php png = an image file format php = a sort of more secure, advanced html (web page format) With that substitution of png for php, David's message all seems correct. On 4/12/2021 7:22 AM, lmcdavid wrote: As I received the email, the graphic file was attached, not embedded. Thunderbird displays attached .jpg files at he bottom of the email, but not .php files such as this graphic file. I have .php file types associated with IrfanView 64 so when I clicked on the attached file name, it opened immediately in IrfanView, my preferred (free) graphic file viewer.If using webmail instead of local client email, operation may be different.Embedded files, at best, are unpredictable."Prove it" indeed!LarrySent via the Samsung Galaxy S20 ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] PM6681 Counter Backup Battery
[This message is essentially a repost. See Note at bottom for details.]
The PM6681 counter (or CNT-81) has a small battery inside. It backs up,
when the counter has no AC power, a section of SRAM memory. That memory
holds a calibration constant that affects the accuracy of the counter's
interpolation method for measurements. This memory also holds more
mundane things like save and recall of counter user setups.
The battery should last for 5 to 10 years, but it is probably a good
idea to replace it with a fresh battery every 5 years or so.
The backup battery is a single standard CR2032-style lithium 3V coin
cell. To open the case there are 3 torx head screws. One in the bottom
center (T10 size) and two at the back plastic feet (T20 size). With the
screws our, I started the opening process by prying with a small
screwdriver in the cracks between the plastic front panel and the case.
To keep the RAM memory intact, the counter must have AC applied and be
in Standby. To remove the battery the holder has openings toward the
front of the counter where you gently pry up the battery. I used a
plastic screw driver adjustment tool. The new battery easily slides in
the way the old one came out. For maximum long term goodness avoid
touching the new cell with bare hands (possibly a bit too anal-retentive).
Hopefully a small pic I took of the battery location will be attached.
-Rex
[Note: I originally made this post as a reply to Bert in the thread
"PM6681 PROMs v109". When I posted, I messed something up on the sending
end which made the email look like it came from Bert ('ew') rather than
from me (rexa).
This reposting is to fix that attribution and also to update the
Subject, as this battery is unrelated to the PROMs.]
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[time-nuts] PM6681 PROMs v109
I have a Fluke PM6681 Counter On the ko4bb site there is an image of the counter's v1.05 PROMs. I just pulled the v1.09 PROMs from my counter and read out the contents. I have placed the result here: http://www.xertech.net/pm6681/Fluke_PM6681_Counter_PROM_v109.zip Anyone interested, please download. If you see any issues or improvement suggestions, please let me know. If all is well in a few days I'll look into uploading this to ko4bb. Back story below I have been following and participating in the thread "Frequency Counter Choice". There has been a long discussion about the PM6681/Cnt-81 counter, mostly about saving and restoring one calibration parameter that gets lost if the internal backup battery dies. A method was described, but currently seems unresolved if the restore method works as hoped. This promped me to open my PM6681 and ensure the battery was good. Having done that, I knew about the v1.05 PROM image but had never seen a v1.09 image. I decided to unplug the AC power and carefully remove the two v1.09 PROMs from my counter. I read out their contents with a reader/programmer tool I have. I returned the PROMs to my counter, applied AC, and the counter seems to be working fine. The link provided above is my sharing of the results of this exercise. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Frequency Counter Choice
Stijn, Sorry to hear writing the string I read out hasn't worked so far. Magnus, Earlier in this thread (date 11/9) you said, "In order to write, you need to move the calibration jumper inside." Do you recall, is there any truth to that? I only saw it mentioned in that one message and I thought maybe you were thinking of the Unprotect command (:SYST:UNPR;) that must precede the PUD write. I'm not sure I really understand all the concepts of the process that the PC program drives to find the CALPLS parameter. If it actually iterates through many values of this parameter to make the tests, then there must be a GPIB way to set it without a power cycle. I'm just speculating. -Rex On 11/11/2020 6:23 AM, Magnus Danielson wrote: Stijn, Have you tried to power-cycle your counter? May seem like a silly question, but just to make sure we are on the same page. I have had similar problems, but did not debug them all. I do remember that after writing the string successfully I had to power-cycle the counter thought, before it got accepted and past Calibration Lost message. When I did this I could not rule out that my programming to control the USB-GPIB infterface was correct, as I bone-headidly wrote my own from ground up. At the time all the stuff with GPIB was flimsy so that's why I just did not use what was available. Cheers, Magnus On 2020-11-11 11:46, Stijn wrote: Hi All, I am one of the lucky persons with a PM6681 that has lost it's calibration parameters. Unfortunatly it seems not as simple as sending: :SYST:UNPR; *PUD #261 CALIBRATED: 2006-11-07, CALPLS: 4.25 ns, TMP: +22 °C This produces an error. If I sent: :SYST:UNPR; *PUD #253 CALIBRATED: 2006-11-07, CALPLS: 4.25 ns, TMP: +22 °C Then the counter accepts the string and stores it. BUT, I still get the Calibration Lost message. btw. the LF at the end of the string you receive from the counter is added by the counter itself, so it does not count for the charactercount. I do have a different firmware version: PHILIPS, PM6681, 0, MAIN V1.05 27 Jan 1997 / GPIB V1.13 27 Jan 1997 Stijn Op 09-11-2020 om 17:47 schreef Rex: Magnus and Azelio, (About Pendulum or Fluke or Philips PM6681 Counter or equivalent CNT-81) Here's a link to the thread where Magnus shared info in 2015. https://time-nuts.febo.narkive.com/6WTFfsyN/pm6680-or-53131a-for-timepod Your post is about half way down -- 2015-11-18 22:18:04 UTC Yesterday I dug out my GPIB-capable PC and sent a couple commands to my Fluke PM6681. First I tried a basic one: *IDN? and got PHILIPS, PM6681, 0, MAIN V1.09 26 JAN 2001 / GPIB V1.13 26 JAN 2001 So connection is good. Interestingly the *IDN command description says the PM6681 will return its SN but the SN field here is 0. Oh well, not important. Then I sent *PUD? and got #261 CALIBRATED: 2006-11-07, CALPLS: 4.25 ns, TMP: +22 °C[LF] where the [LF] at the end is not literal, it represents the line feed char 0x0a. So in addition to the CALPLS value, it looks like they also save the TMP in centigrade when the test was run. I wonder if the counter uses that? So I hope if my counter ever lost this cal value, I could send it this command: :SYST:UNPR; *PUD #261 CALIBRATED: 2006-11-07, CALPLS: 4.25 ns, TMP: +22 °C I don't plan to try that now. If it ain't broke don't fix it. There is one odd thing I see though. The last two of #261 is supposed to say the string length is 61. But it isn't. I count it as 53 chars. I don't know if this matters but the counter gave that number to me. In the Programming Manual description page for *PUD, it gives a couple examples and the #2nn values shown do have lengths that match their string lengths. If it is useful to anyone, I made a version of just the *PUD command description from the Programming Manual and put it here: www.xertech.net/pm6681/PUD_cmd.pdf I also made a version of the Interpolater calibration process page from the Service Manual. It can't really be used since it is obsolete and the old DOS program seems unobtanium. It may give a few hints what they were up to. I put it here: www.xertech.net/pm6681/interpolate_cal.pdf So thanks for pointing out that the *PUD command saved string is what you lose if the memory backup battery dies. Reading and saving the value is what I hoped for and now I've done it. If anyone has a PM6681 counter or equivalent with the "Cal.Lost" message, sending my string above might be good enough to get it working, though maybe not optimum. On 11/9/2020 1:58 AM, Magnus Danielson wrote: Thanks for the memory refresh. You can read the string using PUD? Do that and keep the result. PUD and PUD? is the magic in the counter, the rest is software and hardware outside of the counter for calibration. In order to write, you need to move the calibration jumper inside. Cheers, Magnus On 2020-11-08 23:01, Azelio Boriani wrote: Old story about the PM6681 (18 Nov 2015, thre
Re: [time-nuts] Frequency Counter Choice
Magnus and Azelio, (About Pendulum or Fluke or Philips PM6681 Counter or equivalent CNT-81) Here's a link to the thread where Magnus shared info in 2015. https://time-nuts.febo.narkive.com/6WTFfsyN/pm6680-or-53131a-for-timepod Your post is about half way down -- 2015-11-18 22:18:04 UTC Yesterday I dug out my GPIB-capable PC and sent a couple commands to my Fluke PM6681. First I tried a basic one: *IDN? and got PHILIPS, PM6681, 0, MAIN V1.09 26 JAN 2001 / GPIB V1.13 26 JAN 2001 So connection is good. Interestingly the *IDN command description says the PM6681 will return its SN but the SN field here is 0. Oh well, not important. Then I sent *PUD? and got #261 CALIBRATED: 2006-11-07, CALPLS: 4.25 ns, TMP: +22 °C[LF] where the [LF] at the end is not literal, it represents the line feed char 0x0a. So in addition to the CALPLS value, it looks like they also save the TMP in centigrade when the test was run. I wonder if the counter uses that? So I hope if my counter ever lost this cal value, I could send it this command: :SYST:UNPR; *PUD #261 CALIBRATED: 2006-11-07, CALPLS: 4.25 ns, TMP: +22 °C I don't plan to try that now. If it ain't broke don't fix it. There is one odd thing I see though. The last two of #261 is supposed to say the string length is 61. But it isn't. I count it as 53 chars. I don't know if this matters but the counter gave that number to me. In the Programming Manual description page for *PUD, it gives a couple examples and the #2nn values shown do have lengths that match their string lengths. If it is useful to anyone, I made a version of just the *PUD command description from the Programming Manual and put it here: www.xertech.net/pm6681/PUD_cmd.pdf I also made a version of the Interpolater calibration process page from the Service Manual. It can't really be used since it is obsolete and the old DOS program seems unobtanium. It may give a few hints what they were up to. I put it here: www.xertech.net/pm6681/interpolate_cal.pdf So thanks for pointing out that the *PUD command saved string is what you lose if the memory backup battery dies. Reading and saving the value is what I hoped for and now I've done it. If anyone has a PM6681 counter or equivalent with the "Cal.Lost" message, sending my string above might be good enough to get it working, though maybe not optimum. On 11/9/2020 1:58 AM, Magnus Danielson wrote: Thanks for the memory refresh. You can read the string using PUD? Do that and keep the result. PUD and PUD? is the magic in the counter, the rest is software and hardware outside of the counter for calibration. In order to write, you need to move the calibration jumper inside. Cheers, Magnus On 2020-11-08 23:01, Azelio Boriani wrote: Old story about the PM6681 (18 Nov 2015, thread: "PM6681 and Timelab") where a sort of calibration procedure is described: the PUD command is NOT a calibration command. PM6681 programming manual, page 9-127: PUD Protected User Data...This is a data area where the user may write ANY data up to 64 characters... If the user can write any data, how can it be a calibration command or calibration data area? Better watch out those 3V coin cells, we will never get the real calibration commands/procedure. I have tried with the disassembled firmware, no way. The visible strings of GPIB commands are all described in the programming manual, so nothing useful. On Sat, Nov 7, 2020 at 3:31 AM Magnus Danielson wrote: Hi Rex, I need to dig in the archive to refresh my memory. I don't recall precisely, but I think I recalled that the manual indirectly describes the calibration data string. I have learned a few things from Pendulum, but I did not have the right tools at hand to set things up. There was a more recent setup that could use more modern generators, but the trick was still the same. You lock the generator and counter to the same frequency, then you set the generator to a small offset frequency from 10 MHz, which is 9.999 MHz as I recall it. This slowly sweeps through all the phase-relationships between the reference oscillator and the counter input, thus sweeps the interpolator phase. It then chooses the calibration constant giving the lowest RMS error, as this is the best compensation for the hardware min-point. All this is free from memory. Then that value with calibration date is written into memory. If I recall correctly 2.21 ns is a typical value. I have PM6681 in need of calibration, and as I recall it I was able to program it enough for the calibration error warning did not show up. This not to say it was actually calibrated. At some point I will return to that project. The generator I used did not support that offset frequency, but I have others that do. Also, my crapiola GPIB programming needs attention. My intention is to share the fruits of this project when it comes to that. The lab has been in shambles for too long, but s
Re: [time-nuts] Frequency Counter Choice
Hi Magnus, Just catching up on list messages and saw this one from you. I have a Fluke PM 6881 counter. I don't think I've ever seen a description of a method for reading/restoring these battery backed up calibration constants. I looked for a way, as losing them is something I've worried about. Not that it has happened and I did replace the battery once. Is doing this described in one of the manuals? Sounds like it is through GPIB? I'd greatly appreciate any pointers to info or other details you might provide. I did see, in the service manual, a short description of a method for Interpolator calibration that seems to be for making these calibrations. Seems if the saved cal values get lost, the counter will display "CaL.LOSt". The cal procedure is driven by an old DOS program (that I've never found) and requires a: PM5768 Pulse gen, PM5193 LF Sig Gen, good 10 MHz, all GPIB controlled from the program. Never saw more details but sounds messy. If there is description of GPIB commands for reading/setting cal values, I missed them. thanks for mentioning this and anything more you can provide -Rex On 10/29/2020 5:37 PM, Magnus Danielson wrote: Hi, I second this. You can read the calibration data out of the counter and save. I've done some experiments with that, but nothing conclusive, but I blame my lack of patience and not a proper setup. Do replace the battery, it is cheap and relatively easy to do. Would you loose this calibration, through a little GPIB commands one can write a fake value in. This will however not produce the best resu. The calibration routine actually runs an off beat frequency and then test different values, and look for least RMS value, because it is the calibration point. I've not had time to replicate all that, but I did manage to write the fake value in and at one time get rid of the CAL LOST warning. Cheers, Magnus On 2020-10-29 14:17, Azelio Boriani wrote: For those who have the PM6681 (aka CNT81): check the 3V memory backup cell and replace it before the dreaded calibration lost (CAL LOST) will appear on the LCD. Replace the coin cell with great care (with the counter powered up), see the service manual for the procedure. <https://archive.org/details/FLUKE_PM6681_Service_Manual> On Fri, Oct 23, 2020 at 6:17 PM Magnus Danielson wrote: Hi, On 2020-10-22 19:13, Attila Kinali wrote: On Thu, 22 Oct 2020 11:50:08 + Giorgio Barinetti wrote: Choices are many, but I'll try to avoid the "older" machines lile 5370 or 5335. The 531xx series seems nice ( money apart ) But again : which one between the 3 ? 53131, 53132 or 53181 ? Maybe try to get hold of one of the Philips (later licensed to Fluke) PM6680 or PM6681? These are more common in Europe than in the US, so the big US dominated websites/forums/.. don't mention them that often. Solid devices that can be had as low as 300€ if you are willing to wait, 500-800€ is the usual going price. The SR620 is the workhorse that drives a lot of the time and frequency metrology worldwide and can be had new and used (new on http://thinksrs.com goes for 800-2000€ used). If you go for a new one, I would consider looking at the Pendulum CNT-90 and CNT-91. (Pendulum is the company that took over Philips frequency counter business and the CNT-90 is the continuation of the PM668x line, also sold as PM6690 by Fluke) Let me correct on the history and geniology there. Philips had a instrument making side called Philips Industrier Järfälla that did a range of measurement instruments. Later they joined forces with Fluke. Later Philips felt that the business unit was a bad fit to stay in Philips, so they sold it off to become a separate company which became Pendelum. Pendelum was really the business unit with people etc through that process, and the Fluke relation and rebranding continued. Naturally Pendelum moved out of the Philips Industrier Järfälla office over to Bälstabro (both locations in north of Stockholm) as it was sold off. Pendelum also managed to rebrand their counters to Tektronix, which mainly consisted of cosmetic changes to get the look and feel. Pendelum was operated for many years like this, some of their production in Pajala, where as other where done in Bälstabro. Later they reshaped the production so that it moved to Poland where it remains. Pendulum was sold to Spectracom and was operated as a subsidary for a while, until they shut operation down. The CNT-80/81 (PM 6680 and PM6681) production went on as long as they had the timing ASIC. The CNT-90 (100 ps) was developed to the CNT-91 (50 ps), where the later replaced the CNT-81 (50 ps). They aimed to do the CNT-92, but could not at that time do it with the same technical setup. They also had the Wander Meter WM-10 which aided in testing telecom sync. After some testing, I suggested they would broaden the product to handle more signals and that is when they mostly firmware up
[time-nuts] GPIB interfaces these days
So I've got some test equipment devices (mostly HP) with GPIB (or actually HPIB) connectors. Also a few others as non-HP stuff. Mostly I have talked to them with a NI GPIB card in a PCMCIA slot in a laptop. Works great but the small notebook PC I have with a PCMIA slot is from the early 2000's and I'm worrying what if it dies. It is running XP but usually not on the internet. I also have a couple very early aluminum case Prologix USB interfaces that I haven't tried to use in 10 years. I think I remember hearing these early ones had some issues, and I'd have to dig to re-learn how to talk to them. So I haven't looked at GPIB interface devices in a long time but I'm getting a bit paranoid about the good NI PCMCIA card in a very old PC. I don't remember seeing much discussion about this lately. Is there anything new I should look at. I would have thought there might be something with Arduino or maybe Ras Pi by now, possibly needing some interfacing hardware, but I'm not aware of anything. So, any advice from the group? Old or new. Are my very old Prologix interfaces still worth looking at? -Rex ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
