Re: [time-nuts] HP 5345A
John, Thanks for the good news! I foresee a late evening with plenty of time with the trimmers. Is the lock-range mentioned in the HP-manual? Happy new year to everyone! -- Björn On Sat, December 30, 2006 0:51, John Miles said: There is probably nothing wrong with it. Two things to check: first, the lock range is super-narrow. Make sure that the 10811s are very close to each other using the manual trimmer(s). For the same reason, both OCXOs will need to warm up for a few minutes. Second, the 5345A needs an unusually-strong signal at the external reference jack, about +6 dBm or better if you're driving it from a 50-ohm source. The input load is actually in the 1K neighborhood, not 50 ohms. I've added a MAV-11 MMIC at the external-input jack on the A8 assembly on both of the 5345As I've owned. None of my gear has had problems running from a CATV splitter on the Thunderbolt, except the 5345A. -- john, KE5FX I have another problem with my 5345A. It works fine using the internal oscillator, but when feeding an external oscillator (in this case an 10811 from another counter) it refuses to do anything. Is this a common problem, or is there som kind of magic involved that needs care in the phaselocking of the internal oscillator? ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP 5345A
I don't believe it's mentioned anywhere in the 5345A manual, but I'd guess it's in the 10811A manual. Of course, the counter may not take advantage of the entire available EFC control-voltage range. -- john, KE5FX John, Thanks for the good news! I foresee a late evening with plenty of time with the trimmers. Is the lock-range mentioned in the HP-manual? Happy new year to everyone! -- Björn ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP 5345A
Just like with wine, making good crystals involves a lot of knowledge and a little bit of magic... Happy new year! Didier KO4BB Bill Hawkins wrote: Brooke, I foresee a discussion similar to those of wine connoisseurs. What is the maison and vintage of the crystal? Was it found on the upper or lower slope of the hill? Who cut it and when and how? Is it properly contained? What do the critics (with finer equipment than mine) say about the ability of the crystal to age well? Happy New Year, all. At least, may it start out with a sustainable level of happiness. But if it doesn't, may you have some good fortune before the Odometer of Time clicks off another year, and we get to start over. Regards, Bill Hawkins (Sorry to introduce a light note into these heavy discussions. I hope some will appreciate it.) ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
[time-nuts] HP 5345A
I just picked up a 5345A from eBay. This unit has a 10811 oscillator instead of the 10544 depicted in the manuals I have. The serial number has been removed. Does anyone know if there is an EFC adjustment for this counter or is the course control the only way of setting frequency? Colin __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP 5345A
The 5345A does not have a EFC adjustment, so your only option is the frequency adjust pot on top side of the 10811 oscillator. Greg - Original Message - From: Colin Bradley [EMAIL PROTECTED] To: time-nuts@febo.com Sent: Friday, December 29, 2006 11:01 AM Subject: [time-nuts] HP 5345A I just picked up a 5345A from eBay. This unit has a 10811 oscillator instead of the 10544 depicted in the manuals I have. The serial number has been removed. Does anyone know if there is an EFC adjustment for this counter or is the course control the only way of setting frequency? Colin __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP 5345A
John Miles wrote: There's no manual fine-tuning adjustment on the 10811A, which is something I've always found strange. The trimmer that is present is arguably far too coarse. I've owned 10811As that would stay put within a couple parts in 1E-10 per year, but setting them to that degree of precision was a real pain. I think you meant 1E-10 per DAY, not per year. Rick Karlquist N6RK ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP 5345A
Colin Bradley wrote: I just picked up a 5345A from eBay. This unit has a 10811 oscillator instead of the 10544 depicted in the manuals I have. The serial number has been removed. Does anyone know if there is an EFC adjustment for this counter or is the course control the only way of setting frequency? Colin I don't know of any instrument in the history of HP/Agilent that ever used the EFC as a fine manual frequency adjustment. The EFC was only ever used as a phase locking interface. The tuning adjustment is adequate for annual calibration purposes (IE, you can set it within 1 Hz, or 1E-7 if you are careful, and the expected annual aging is in that ballpark). Rick Karlquist N6RK ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP 5345A
The HP 5328A that I have uses the EFC as a fine manual adjust. There is an accessory card that accepts the oscillator and the supporting fine manual-adjust circuitry is located there. Bill, K8CU - Original Message - From: Rick Karlquist [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Cc: time-nuts@febo.com Sent: Friday, December 29, 2006 8:04 PM Subject: Re: [time-nuts] HP 5345A Colin Bradley wrote: I just picked up a 5345A from eBay. This unit has a 10811 oscillator instead of the 10544 depicted in the manuals I have. The serial number has been removed. Does anyone know if there is an EFC adjustment for this counter or is the course control the only way of setting frequency? Colin I don't know of any instrument in the history of HP/Agilent that ever used the EFC as a fine manual frequency adjustment. The EFC was only ever used as a phase locking interface. The tuning adjustment is adequate for annual calibration purposes (IE, you can set it within 1 Hz, or 1E-7 if you are careful, and the expected annual aging is in that ballpark). Rick Karlquist N6RK ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP 5345A
No; per year. The 10811(D?) in a late-model 8662A I owned a few years ago was a serious outlier. If I remember correctly, it was about 3E-10 off after being left on for a year. I'll never find the notes I kept on it now, but it was definitely better than 1E-9. 1E-7 adjustment precision, if that's what they were aiming for, was nowhere near adequate for the 10811 series. -- john, KE5FX -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Rick Karlquist Sent: Friday, December 29, 2006 12:00 PM To: Discussion of precise time and frequency measurement Cc: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 5345A John Miles wrote: There's no manual fine-tuning adjustment on the 10811A, which is something I've always found strange. The trimmer that is present is arguably far too coarse. I've owned 10811As that would stay put within a couple parts in 1E-10 per year, but setting them to that degree of precision was a real pain. I think you meant 1E-10 per DAY, not per year. Rick Karlquist N6RK ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP 5345A
Boxes such as the 105A/B (and others) use the EFC as a fine manual frequency adjustment. For boxes without EFC manual adjustment, it's possible to set the 10811 to 3E-10 or better if you're careful and willing to go through a few iterations over a few days. At time of performance check (of boxes containing the 10811) at Agilent Service Centers, the allowable offset for 10811 equals +/- 5E-8. If outside that allowable offset window, it must be optimized to nominal within a limit equal to +/- 5E-9. This is a customer-driven metrology policy (that was developed with the cooperation of several HP divisions, including Santa Clara) and adopted world-wide by HP/Agilent Services and Support Unit. Purpose of the policy is to define and standardize when to re-adjust oscillators, and is not a Santa Clara hard-spec. ...Cheers, Greg Burnett Rick Karlquist wrote: I don't know of any instrument in the history of HP/Agilent that ever used the EFC as a fine manual frequency adjustment. The EFC was only ever used as a phase locking interface. The tuning adjustment is adequate for annual calibration purposes (IE, you can set it within 1 Hz, or 1E-7 if you are careful, and the expected annual aging is in that ballpark). Rick Karlquist N6RK ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP 5345A
John Miles wrote: No; per year. The 10811(D?) in a late-model 8662A I owned a few years ago was a serious outlier. If I remember correctly, it was about 3E-10 off after being left on for a year. I'll never find the notes I kept on it now, but it was definitely better than 1E-9. It probably wandered around much more than that during the year and you just happened to measure it when it was close to the starting point. Kind of like the broken clock that keeps perfect time every 12 hours. In any event, I can safely say, having looked at thousands of 10811's, that I have never seen one that had anything like that level of aging. Rick Karlquist N6RK ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP 5345A
It probably wandered around much more than that during the year and you just happened to measure it when it was close to the starting point. Kind of like the broken clock that keeps perfect time every 12 hours. In any event, I can safely say, having looked at thousands of 10811's, that I have never seen one that had anything like that level of aging. I thought aging was generally uni-directional and reasonably predictable if you had enough data. Does it wander in both directions? -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP 5345A
I don't recall; this oscillator was installed in a piece of gear I sold several years ago. I checked it every few months while I had it. All I remember is that the note I used to keep track of its calibration had at least four entries on it at the time I sold the generator, and I'm very sure it never left +/- 1E-9, always measured after the 8662A had been left running for at least a couple of hours. Whether it looked like a random walk or not, I couldn't say. Lucky environmental factors must have played a big part because -- as Rick says -- they aren't normally that stable. There is a definite bathtub-shaped curve at work, as well. If the units that Rick saw at Agilent were all brand-new, then of course they weren't very stable compared to the OCXO in this 8662A. I could tell that it had been running for a long time when I received it, because I observed almost no accelerated aging during the first few weeks of service. Likewise, from what I have seen, the early-80s OCXOs don't tend to stay put as well as the newer ones do. Whether that's due to materials/manufacturing quality or simple aging is impossible to say, given the limited number that I have experimented with. -- john, KE5FX -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Hal Murray Sent: Friday, December 29, 2006 1:29 PM To: [EMAIL PROTECTED]; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 5345A It probably wandered around much more than that during the year and you just happened to measure it when it was close to the starting point. Kind of like the broken clock that keeps perfect time every 12 hours. In any event, I can safely say, having looked at thousands of 10811's, that I have never seen one that had anything like that level of aging. I thought aging was generally uni-directional and reasonably predictable if you had enough data. Does it wander in both directions? ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP 5345A
Hal Murray wrote: I thought aging was generally uni-directional and reasonably predictable if you had enough data. Does it wander in both directions? This is probably on the list of the 10 greatest myths about crystal oscillators. Many decades ago, there were systematic aging effects such as you speak of. I remember learning as a youth that glass crystals age up and metal crystals age down. Over the years, any such systematic effects have been analyzed one by one to understand the root cause, and then the process has been fixed to get rid of that aging effect. What we are now left with are tiny cracks and crevasses that grow sporadically like a crack in an auto windshield. At least that is what we think is going on. The process people, like my friends Charles Adams and Jack Kusters, have worked themselves out of a job had taken retirement, because, like the efficient stock market theory, there is no predictability to the aging data. It is truly a random walk down Wall Street or in this case a random walk in time. Oscillators will age in one direction for a while but may then age in the opposite direction for while for no particular reason. Not only that, but crystals will jump a part in 1E^9 or so every so often. I've never seen a 10811 crystal without jumps if you wait long enough. I don't know of any other crystal makers who claim to not have jumps. Rick Karlquist N6RK ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP 5345A
In message [EMAIL PROTECTED], Rick Karlquist writes: Hal Murray wrote: I thought aging was generally uni-directional and reasonably predictable if you had enough data. Does it wander in both directions? Yes, see for instance: http://phk.freebsd.dk/misc/drift.png -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | 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 https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP 5345A
What's the Y-axis on that graph? Parts in 1E-9? -- john, KE5FX Yes, see for instance: http://phk.freebsd.dk/misc/drift.png ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
[time-nuts] HP 5345A
In looking at the manual for the 5334A/B, the oscillator support board has a trimmer (R5) that could be used for EFC control of the 10811A. Too bad that HP did not use EFC (or an internal FINE control) to set frequency on this great unit in more of there instruments Colin __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP 5345A
In message [EMAIL PROTECTED], John Miles writes: What's the Y-axis on that graph? Parts in 1E-9? Yes. n for nano. It's an ISOTEMP OCXO 131 Yes, see for instance: http://phk.freebsd.dk/misc/drift.png ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | 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 https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP 5345A
From: Rick Karlquist [EMAIL PROTECTED] Subject: Re: [time-nuts] HP 5345A Date: Fri, 29 Dec 2006 14:39:09 -0800 (PST) Message-ID: [EMAIL PROTECTED] Hal Murray wrote: I thought aging was generally uni-directional and reasonably predictable if you had enough data. Does it wander in both directions? Rick, Allways enjoy your insightfull postings. This is probably on the list of the 10 greatest myths about crystal oscillators. Many decades ago, there were systematic aging effects such as you speak of. I remember learning as a youth that glass crystals age up and metal crystals age down. Over the years, any such systematic effects have been analyzed one by one to understand the root cause, and then the process has been fixed to get rid of that aging effect. I assume we are talking about fairly top of the line units here, such as the 10811 and friends. I'm sure that the really cheap AT crystals all over the place still show some of these old behaviours even the average quality may have improved. What we are now left with are tiny cracks and crevasses that grow sporadically like a crack in an auto windshield. At least that is what we think is going on. The process people, like my friends Charles Adams and Jack Kusters, have worked themselves out of a job had taken retirement, because, like the efficient stock market theory, there is no predictability to the aging data. It is truly a random walk down Wall Street or in this case a random walk in time. Oscillators will age in one direction for a while but may then age in the opposite direction for while for no particular reason. Not only that, but crystals will jump a part in 1E^9 or so every so often. I've never seen a 10811 crystal without jumps if you wait long enough. I don't know of any other crystal makers who claim to not have jumps. I've seen some measures of crystals being held at a constant temperature for several years and they show only a decaying glide as a continous process over all those years. I think they where 3-4 years. I could dig the reference up but it might take some time. It was a rather old experiment thought. You should have seen it. Cheers, Magnus ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP 5345A
Hi Rick: Is there a way to know about the type of aging up front. For example what crystal makers have only micro cracks as the aging mechanism? For what starting date? My guess is that there are plenty of crystals that have aging that's mainly due to contamination or other causes that the better makers have eliminated. Have Fun, Brooke Clarke w/Java http://www.PRC68.com w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml http://www.precisionclock.com Rick Karlquist wrote: Hal Murray wrote: I thought aging was generally uni-directional and reasonably predictable if you had enough data. Does it wander in both directions? This is probably on the list of the 10 greatest myths about crystal oscillators. Many decades ago, there were systematic aging effects such as you speak of. I remember learning as a youth that glass crystals age up and metal crystals age down. Over the years, any such systematic effects have been analyzed one by one to understand the root cause, and then the process has been fixed to get rid of that aging effect. What we are now left with are tiny cracks and crevasses that grow sporadically like a crack in an auto windshield. At least that is what we think is going on. The process people, like my friends Charles Adams and Jack Kusters, have worked themselves out of a job had taken retirement, because, like the efficient stock market theory, there is no predictability to the aging data. It is truly a random walk down Wall Street or in this case a random walk in time. Oscillators will age in one direction for a while but may then age in the opposite direction for while for no particular reason. Not only that, but crystals will jump a part in 1E^9 or so every so often. I've never seen a 10811 crystal without jumps if you wait long enough. I don't know of any other crystal makers who claim to not have jumps. Rick Karlquist N6RK ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP 5345A
They probably assumed that most hardcore users would lock the counter or generator to a house standard anyway. (You might point out that only hardcore users would have paid $15,000+ for a 5345A, but the practically-new one that I just bought was owned by the New Jersey State Police!) It's interesting that the 5345A phase-locks its internal OCXO while the 5370A/B does not. I guess in the 5370's case, HP didn't want to be accused of degrading the jitter of a hypothetical super-clean external source. But why bother phase-locking the OCXO in the 5345A? The practical upshot of that is that you have to leave the 5345A plugged in to avoid warmup delays, while the 5370B can stay on a switched outlet. -- john, KE5FX In looking at the manual for the 5334A/B, the oscillator support board has a trimmer (R5) that could be used for EFC control of the 10811A. Too bad that HP did not use EFC (or an internal FINE control) to set frequency on this great unit in more of there instruments Colin ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP 5345A
On Fri, December 29, 2006 19:01, Colin Bradley said: I just picked up a 5345A from eBay. This unit has a 10811 oscillator instead of the 10544 depicted in the manuals I have. The serial number has been removed. Does anyone know if there is an EFC adjustment for this counter or is the course control the only way of setting frequency? Colin I have another problem with my 5345A. It works fine using the internal oscillator, but when feeding an external oscillator (in this case an 10811 from another counter) it refuses to do anything. Is this a common problem, or is there som kind of magic involved that needs care in the phaselocking of the internal oscillator? -- Björn ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP 5345A
There is probably nothing wrong with it. Two things to check: first, the lock range is super-narrow. Make sure that the 10811s are very close to each other using the manual trimmer(s). For the same reason, both OCXOs will need to warm up for a few minutes. Second, the 5345A needs an unusually-strong signal at the external reference jack, about +6 dBm or better if you're driving it from a 50-ohm source. The input load is actually in the 1K neighborhood, not 50 ohms. I've added a MAV-11 MMIC at the external-input jack on the A8 assembly on both of the 5345As I've owned. None of my gear has had problems running from a CATV splitter on the Thunderbolt, except the 5345A. -- john, KE5FX -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Friday, December 29, 2006 3:41 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 5345A On Fri, December 29, 2006 19:01, Colin Bradley said: I just picked up a 5345A from eBay. This unit has a 10811 oscillator instead of the 10544 depicted in the manuals I have. The serial number has been removed. Does anyone know if there is an EFC adjustment for this counter or is the course control the only way of setting frequency? Colin I have another problem with my 5345A. It works fine using the internal oscillator, but when feeding an external oscillator (in this case an 10811 from another counter) it refuses to do anything. Is this a common problem, or is there som kind of magic involved that needs care in the phaselocking of the internal oscillator? ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP 5345A
Brooke, I foresee a discussion similar to those of wine connoisseurs. What is the maison and vintage of the crystal? Was it found on the upper or lower slope of the hill? Who cut it and when and how? Is it properly contained? What do the critics (with finer equipment than mine) say about the ability of the crystal to age well? Happy New Year, all. At least, may it start out with a sustainable level of happiness. But if it doesn't, may you have some good fortune before the Odometer of Time clicks off another year, and we get to start over. Regards, Bill Hawkins (Sorry to introduce a light note into these heavy discussions. I hope some will appreciate it.) -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Brooke Clarke Sent: Friday, December 29, 2006 5:21 PM To: [EMAIL PROTECTED]; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 5345A Hi Rick: Is there a way to know about the type of aging up front. For example what crystal makers have only micro cracks as the aging mechanism? For what starting date? My guess is that there are plenty of crystals that have aging that's mainly due to contamination or other causes that the better makers have eliminated. Have Fun, Brooke Clarke w/Java http://www.PRC68.com w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml http://www.precisionclock.com Rick Karlquist wrote: Hal Murray wrote: I thought aging was generally uni-directional and reasonably predictable if you had enough data. Does it wander in both directions? This is probably on the list of the 10 greatest myths about crystal oscillators. Many decades ago, there were systematic aging effects such as you speak of. I remember learning as a youth that glass crystals age up and metal crystals age down. Over the years, any such systematic effects have been analyzed one by one to understand the root cause, and then the process has been fixed to get rid of that aging effect. What we are now left with are tiny cracks and crevasses that grow sporadically like a crack in an auto windshield. At least that is what we think is going on. The process people, like my friends Charles Adams and Jack Kusters, have worked themselves out of a job had taken retirement, because, like the efficient stock market theory, there is no predictability to the aging data. It is truly a random walk down Wall Street or in this case a random walk in time. Oscillators will age in one direction for a while but may then age in the opposite direction for while for no particular reason. Not only that, but crystals will jump a part in 1E^9 or so every so often. I've never seen a 10811 crystal without jumps if you wait long enough. I don't know of any other crystal makers who claim to not have jumps. Rick Karlquist N6RK ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
[time-nuts] HP 5345A - Any Experts?
I got a HP 5345A off eBay, and it is in mint condition. I took the top off and no dust on the inside or anything, I could hardly believe it. However, when I went to hookup a signal to the input... Nothing! All the internal self-tests passed, but those bypass the front inputs. I looked through the manual for some hint of a fuse or something, but could not find anything. I also pulled the front display off to check the PCB that the BNC inputs go into and everything looked okay on them too. Does anyone know if there is a hidden fuse somewhere that I should check? Also is there some test points I can check to see if a signal is getting through the front? I would rather not have to ship this back since I could probably search forever and not find one in better physical condition, but if it doesn't work, it doesn't work... Jason ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP 5345A - Any Experts?
I thought about that (getting a parts unit), but to be honest I'm no repair expert and would probably end up doing more damage than good. Another list member contacted me with some info about what he thought could be wrong, and I ended up selling it to him since he was interested in it and thinks he can repair it. I broke even I'm happy it found a good home. It was in really nice condition, looked like it came off the assembly line yesterday. Now if I can only find me another nice counter in the same condition (except with working inputs of course). Jason Hello Jason, Well, I am not a 5345A expert in any way but I have two units and have worked on them. I guess your unit has a damaged front end. If so and you can return the unit, I think it could be your best option. But all depends on how much have you paid for it; if not too much, you could keep it (perhaps asking seller for a partial refund) and wait for a suitable parts-unit (or just another unit) with a good front end (I got my units at eBay for very reasonable prices). BTW, same input unit is also used in the HP5370A, so that could be another source for the needed parts (I have also two 5370A :-)!) Good luck! JOSE ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP 5345A - Any Experts?
through the manual for some hint of a fuse or something, but could not find anything. I also pulled the front display off to check the PCB that the BNC inputs go into and everything looked okay on them too. Does anyone know if there is a hidden fuse somewhere that I should check? Also is there some test points I can check to see if a signal is getting through the front? Jason Some HP equipment had a fuse built in to the front panel connector. I would verify with a scope that the signal was actually getting to the PC board. Rick Karlquist N6RK ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
