Re: [time-nuts] HP 5371A problem
My 5372A had the same problems. Error: Contact problems in IC sockets and jumpers Remove IC and jumpers and put those back. This solved my problems Juerg ___ 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.
Re: [time-nuts] HP 5371A problem
Thanks. I don't know how I missed those manuals on the Agilent site; I had looked there a while ago. Bill Ezell -- They said 'Windows or better' so I used Linux. Bruce Griffiths wrote: wje wrote: The cpu card in my 5371A seems to have died. It's asserting reset constantly, with lights 1 and 6 on. Unfortunately, my service manual doesn't include any schematics for that card. Does anyone have any suggestions? (other than doing a lot of tedious tracing) Correction: Figure 7G8 on page 7G17 for the processor board schematic. Bruce ___ time-nuts mailing list -- [EMAIL PROTECTED] To unsubscribe, go to [2]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. References 1. mailto:time-nuts@febo.com 2. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ 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.
Re: [time-nuts] HP 5371A problem
On both of my 5370As, the only way to permanently fix socket problems of that type was to replace all the sockets with gold plated, machined pin sockets. On the 5370, that was easy because the boards have relatively large holes compared to the socket pins, and there is no ground plane, so it was easy to unsolder the pins with the good desoldering tool I have access to at work. Prior to that, I had removed all chips and sprayed the sockets with DeOxIt Gold several times, but the problem always came back pretty quickly. I think it was tin wiskers. Didier -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jürg Kögel Sent: Friday, August 08, 2008 4:07 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 5371A problem My 5372A had the same problems. Error: Contact problems in IC sockets and jumpers Remove IC and jumpers and put those back. This solved my problems Juerg ___ 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.
Re: [time-nuts] time-nuts Digest, Vol 49, Issue 12
Date: Thu, 7 Aug 2008 21:50:02 +0100 From: David [EMAIL PROTECTED] Subject: Re: [time-nuts] NavSync CW12 and CW25 To: time-nuts@febo.com Message-ID: [EMAIL PROTECTED] Content-Type: text/plain; charset=us-ascii Ed, I've been playing with a CW12, it basically appears to do what they say but I will not confirm any numbers for the moment, it certainly compares to my VLF derived 10MHz signals. I was looking to build a GPSDO and 10MHz from the GPS Rx seemed a better starting point than 1PPS. My thoughts exactly. I've been playing with a Jupiter GPS board which has a 10 KHz output, but it died on me so I'm that's why I'm looking for a replacement. I'm only now near to completing part two of the exercise, phase locking a 10MHz double oven XO to the CW12 10MHz, the phase noise on the CW12 output is rather significant and needs cleaning for most applications. The ssb numbers I see from the CW12 (using an HP8560E) relative to the 10MHz carrier are : 1kHz -80 dBc/Hz 10kHz -102 dBc/Hz 100kHz -109 dBc/Hz 1MHz -126 dBc/Hz The signal is far from a pure line, close in there is a set of sidebands based on harmonics of 132 with the fundamental at -22dBc, there are various synthesis artefacts. This unit clearly needs filtering. I thought it was good of Navsync to admit in the app note that their signal isn't particularly clean. I'm a rank amateur in this area, but if you changed the output frequency of the CW25 is it possible that you might find a 'sweet spot' that would give you a cleaner signal - either by matching or avoiding various harmonics of the internal clock(s)? I noticed in the datasheet that they spec the processor as 'up to 120 MHz'. If they're saying that the clock speed varies while operating then forget my question. The PLL I've built to clean it up is essentially a simple 2nd/3rd order loop with the phase comparison at 78kHz (sigs divided by 128), my model claims the 3dB closed bandwidth will be 0.3 Hz and sideband suppression about 127dB at 1kHz offset in principle. In reality I'll need to play with it to look at the real world limitations of acquisition, loop BW, analogue offsets etc . Did you divide down the output from the CW12? I see that you can set this frequency, but I wondered if this setting was non-volatile or if the frequency would return to 10 MHz after a loss of power. I'm assuming that the on-board battery would keep it as long as possible. The OCXO I'm locking is a Temex part, a 'Doc1478-D which seems to be from their S110 series. It claims to manage -145dBc at 1kHz offset. There were on ebay at low cost a while ago, everything else has largely been built from scrap which has biased the design ever so slightly, the less it costs the more amusing the project if you are not doing it for a customer. Yeah, it's no fun to just go buy a bunch of parts. Some of my stuff looks like it came out of Dr. Frankenstein's lab. Of course, sometimes you have to dig out your wallet. I picked up a couple of those 'naked' HP Z3801a oscillators (basically HP 10811 oscillators with an second oven) that showed up on Ebay a month or so ago. I'm planning on using that for my OCXO. The 'Frankenstein' aspect will be fulfilled because I'll have to fabricate an outer casing for the oscillator and build a controller for the outer oven. The slight disappointment has been the lack of support information about the CW12 on the web, when I spoke to them in March they said their site was going to be updated by the end of that month, clearly they have dropped the ball somewhere but the email support seems responsive. I asked for the user manual in June and they responded quickly, but didn't mention anything about a website update. I think I've seen the CW25 appear in a recent GPSDO from Quartzlock, have a look at : http://www.quartzlock.com/cgi-bin/servepage.cgi?usr=61390page=tech_DS_E8-X. pdf Yeah, that little module looks familiar doesn't it? The picture's not very clear, but you can just make out the Hirose connector in the corner of the module near the TNC connector. This appears to use a DDS/PLL to clean the reference clock rather than a large and expensive OCXO. Starting afresh I may have gone for the CW25 but I've got the CW12 so not thought much more about it. Regards David Mackenzie (GM4HJQ) Thanks very much for the info, David. Ed ___ 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] NavSync CW12 and CW25
Date: Fri, 8 Aug 2008 14:18:06 +1000 From: Pascal Nguyen [EMAIL PROTECTED] Subject: Re: [time-nuts] NavSync CW12 and CW25 To: Discussion of precise time and frequency measurement time-nuts@febo.com Message-ID: [EMAIL PROTECTED] Content-Type: text/plain; charset=UTF-8 Hi Ed I build a 432.424MHz and 144.424MHz beacons for radio amateur application based on CW25-TIM modules ($150 ea july-07). I cannot provide any further details than the spec published by Navsync, due to lack of measurement facility, my set up is simply a Rb standard and two RT662 HF receivers driven with 5MHz source from Rb 10MHz/2) . Audio outputs are directed to PC soundcard and water falls are visually compared, an entry level for amateur like myself. I etched the PC board for 3V3 SM power supply, backup battery, RS 232 converter (3v level) and 1PPS, NCO output, NMEA output, status LED indicators. My first board was populated with CW25 NAV, the only module available at that time, max freq 10MHz NCO. My second with CW25 TIM, max freq 30 MHz NCO It looks like they've dropped the CW25-NAV. It doesn't seem to be mentioned on their site. They've also reduced the output frequency on the CW25-TIM to 10 MHz. In fact, yours must be a very early model because even digging through old web pages, I can't find any mention of a 30 MHz output. Don't lose that one, you'll never find another like it! Control the NCO is quite simple, via simple protocols, ie 10MHz output is such as $PRTHS,FRQD,10.000.000 . The CW25 TIM, factory default NCO output is 10 MHz, since startup and will lock to 1pps when status fixed, the module is running warm to touch at, I suppose an ovenised crystal is inside. I do not have the CW12, if the module is CW25TIM, it is worthy to get the CW12 to save the pain of etching a PCB. Pascal Nguyen Thanks for the info, Ed ___ 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.
Re: [time-nuts] HP 5371A problem
Thanks, all. In this case, it was a 74ALS1035 OC hex buffer that gave up the ghost. I've temporarily replaced it with 6 diodes, which works like a charm. After all, what's an OC buffer but a diode plus a little 1x gain? Bill Ezell -- They said 'Windows or better' so I used Linux. Jürg Kögel wrote: My 5372A had the same problems. Error: Contact problems in IC sockets and jumpers Remove IC and jumpers and put those back. This solved my problems Juerg ___ 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] Double-Oven Thunderbolt on Ebay
Does anyone have a double-oven thunderbolt like the one that's now listed on ebay? If so, do you have any phase-noise or other performance data on it? -Flavio ___ 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.
Re: [time-nuts] Double-Oven Thunderbolt on Ebay
I don't have any of the 10811-60158s, but I did buy two of the 10811-60168s that were up for auction recently. The -60168s seem to be really good performers (from memory, -106 dBc/Hz at 1 Hz, -139 at 10, -155 at 100, -164 at 1000, when I measured them against each other.) I have never seen any specs for them, or anything else about them. If someone wants to lend one of the -60158s to me, I'll benchmark it against one of the -60268s. Tom or JohnA, have either of you run any Allan plots on a 10811-60268? I'd be curious to see how they do. -- john, KE5FX -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Friday, August 08, 2008 2:25 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Double-Oven Thunderbolt on Ebay Does anyone have a double-oven thunderbolt like the one that's now listed on ebay? If so, do you have any phase-noise or other performance data on it? -Flavio ___ 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.
Re: [time-nuts] Double-Oven Thunderbolt on Ebay
Tom or JohnA, have either of you run any Allan plots on a 10811-60268? I'd be curious to see how they do. Er, -60168, that is. -- john, KE5FX ___ 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.
Re: [time-nuts] Double-Oven Thunderbolt on Ebay
I'm measuring my pair of eBay -60158s right now and will post some results probably after the weekend. I've never seen the -60268s. One thing to note -- good phase noise and good ADEV don't necessarily go together. Case in point is the -60158s are spec'd at 1x10e-12 at 1 second, which is better than most of the 10811A variants, but the phase noise isn't as good as other versions (like the -60258 you have). John - John Miles said the following on 08/08/2008 06:23 PM: I don't have any of the 10811-60158s, but I did buy two of the 10811-60168s that were up for auction recently. The -60168s seem to be really good performers (from memory, -106 dBc/Hz at 1 Hz, -139 at 10, -155 at 100, -164 at 1000, when I measured them against each other.) I have never seen any specs for them, or anything else about them. If someone wants to lend one of the -60158s to me, I'll benchmark it against one of the -60268s. Tom or JohnA, have either of you run any Allan plots on a 10811-60268? I'd be curious to see how they do. ___ 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.
Re: [time-nuts] Double-Oven Thunderbolt on Ebay
John Ackermann N8UR wrote: One thing to note -- good phase noise and good ADEV don't necessarily go together. Case in point is the -60158s are spec'd at 1x10e-12 at 1 second, which is better than most of the 10811A variants, but the phase noise isn't as good as other versions (like the -60258 you have). John Yes, in fact, they have almost nothing to do with each other. Short term stability at 1 second is determined entirely by the crystal and phase noise at 1 kHz is determined almost entirely by the circuit. This is in the 10811 or any decent oscillator. Of course it is possible to use a poorly designed circuit that degrades the 1 s stability (or a really bad oven). And a crystal of much lower Q or higher intrinisic phase noise might affect phase noise. But in practice in the 10811, absent pathological corner cases, what I originally said is accuracy AFAIK. Rick Karlquist N6RK ___ 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.
Re: [time-nuts] Double-Oven Thunderbolt on Ebay
-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Friday, August 08, 2008 4:17 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Double-Oven Thunderbolt on Ebay I was actually talking about this one... http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItemitem=200243779655 not the the HP double ovens. Ah, sorry, my mistake; I was still thinking about those HP oscillators sold by the guy in China. I don't know about these double-oven units, but I will say that the OCXO in the TAPR Thunderbolts is extremely good, about 20 dB quieter at the 1-Hz timescale than the one in my (several-year-old) original Thunderbolt. -- john, KE5FX ___ 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.
