Re: [time-nuts] Warning: HP oscillators on eBay
A couple of years ago I measured this one... ;-) http://www.leapsecond.com/pages/10811-slow/ /tvb ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Warning: HP oscillators on eBay from todoelmondo(Ray Mahoney)
Folks, I hesitate to do this, but I think this topic has gone on long enough and we're not shedding much new light. Let's give it a rest Thanks, John Yr Humble Listmanager ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Warning: HP oscillators on eBay from todoelmondo(Ray Mahoney)
Poul-Henning Kamp wrote: In message <[EMAIL PROTECTED]>, David Kirkby writes: I seriously doubt you will ever get a better and more researched answer than: Tom has said he has tested bad 10811A's and good 10811-60111's. But Tom has not said (to me anyway) if the peformance of the oscillators tested is randomly distributed. Now, don't be unreasonable. I don't think even Tom has enough differeing 10811's to determine if this is so. No, which is what I guessed would be the case. Therefore without any evidence to the contry, it is probably not an unreasonable assumption that on average the performance of a 10811A today is likely to be better than that of a 10811-60111, since the original specification for the former was higher. Btw, have you seen this: http://www.leapsecond.com/museum/10811a/90027-1.pdf Yes, and as you can see, not much is specified about the 10811-60111. No phase noise specifications, no gravitional specifications, no magnetic field specifications and only a single time domain stabilty specification of < 1.0 x 10^-11 at 1s. In contrast, there are much more detailed specs on the 10811A, and the time domain stability at 1s is better (I thnk it is a factor of 2, which would mean the 10811A would need to be < 5 x 10^-12) -- David Kirkby, G8WRB Please check out http://www.g8wrb.org/ of if you live in Essex http://www.southminster-branch-line.org.uk/ ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
RE: [time-nuts] Warning: HP oscillators on eBay from todoelmondo(RayMahoney)
Also, once your GPS standard project is up and running with the -60111, I'm sure that someone on the list would be more than happy to borrow it and compare it to their own Cs or H standard, and give you a short-term stability plot. You can then look at the graph and see if the HP rock is giving you the performance you want, and go from there. Basically, you should sweat this particular detail at the end of the project, not the beginning. The OCXO is replaceable, but the time spent worrying about it isn't. -- john KE5FX > >But Tom has not said (to me anyway) if the peformance of the oscillators > >tested is randomly distributed. > > Now, don't be unreasonable. I don't think even Tom has enough > differeing 10811's to determine if this is so. > > Btw, have you seen this: > http://www.leapsecond.com/museum/10811a/90027-1.pdf > > > ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Warning: HP oscillators on eBay from todoelmondo(Ray Mahoney)
In message <[EMAIL PROTECTED]>, David Kirkby writes: >> I seriously doubt you will ever get a better and more researched >> answer than: >> >>>Tom has said he has tested bad 10811A's and good 10811-60111's. > >But Tom has not said (to me anyway) if the peformance of the oscillators >tested is randomly distributed. Now, don't be unreasonable. I don't think even Tom has enough differeing 10811's to determine if this is so. Btw, have you seen this: http://www.leapsecond.com/museum/10811a/90027-1.pdf -- 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] Warning: HP oscillators on eBay from todoelmondo(Ray Mahoney)
Poul-Henning Kamp wrote: In message <[EMAIL PROTECTED]>, David Kirkby writes: I assumed (perhaps incorrectly) that there would be a higher probability of a randomly chosen 10811A being better today than a randomly chosen 10811-60111. I guess the only way to know this is to test a sufficient number to get statically valid data - something that I doubt few would have sufficient oscillators to be able to do, and even fewer could be bothered to do. I seriously doubt you will ever get a better and more researched answer than: Tom has said he has tested bad 10811A's and good 10811-60111's. But Tom has not said (to me anyway) if the peformance of the oscillators tested is randomly distributed. I don't currently have the facilities to test the oscillator (as I lack sufficient oscillators), so the most obvious thing to do is something I am unable to do. -- David Kirkby, G8WRB Please check out http://www.g8wrb.org/ of if you live in Essex http://www.southminster-branch-line.org.uk/ ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
RE: [time-nuts] Warning: HP oscillators on eBay from todoelmondo(RayMahoney)
Unless it's going into the next Mars probe, I would just hook the thing up and see if it's good enough for the intended application. Time (no pun intended) to move on. -- john KE5FX > Richard (Rick) Karlquist (N6RK) wrote: > > > All 10811-6 are simply selections of one of the above. > > After a lot of time has gone by, these selections are, for the > > most part, irrelevant. > > The specs on the 10811A are higher than on the 10811-60111. If I > remember correctly, there are no phase noise specs at all on the > 10811-60111, and the stability is only specified at 1s and is twice as > poor as the 10811A. (I'm going from memory). > > ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Warning: HP oscillators on eBay from todoelmondo(Ray Mahoney)
In message <[EMAIL PROTECTED]>, David Kirkby writes: >I assumed (perhaps incorrectly) that there would be a higher probability >of a randomly chosen 10811A being better today than a randomly chosen >10811-60111. I guess the only way to know this is to test a sufficient >number to get statically valid data - something that I doubt few would >have sufficient oscillators to be able to do, and even fewer could be >bothered to do. I seriously doubt you will ever get a better and more researched answer than: >Tom has said he has tested bad 10811A's and good 10811-60111's. -- 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] Warning: HP oscillators on eBay from todoelmondo(Ray Mahoney)
Richard (Rick) Karlquist (N6RK) wrote: All 10811-6 are simply selections of one of the above. After a lot of time has gone by, these selections are, for the most part, irrelevant. The specs on the 10811A are higher than on the 10811-60111. If I remember correctly, there are no phase noise specs at all on the 10811-60111, and the stability is only specified at 1s and is twice as poor as the 10811A. (I'm going from memory). Are you simply saying that as these are all old components, any oscillator that was a higher spec 20 years ago has no higher probability of being good today than one that was less good 20 years ago? Tom has said he has tested bad 10811A's and good 10811-60111's. I assumed (perhaps incorrectly) that there would be a higher probability of a randomly chosen 10811A being better today than a randomly chosen 10811-60111. I guess the only way to know this is to test a sufficient number to get statically valid data - something that I doubt few would have sufficient oscillators to be able to do, and even fewer could be bothered to do. -- David Kirkby, G8WRB Please check out http://www.g8wrb.org/ of if you live in Essex http://www.southminster-branch-line.org.uk/ ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
RE: [time-nuts] Warning: HP oscillators on eBay from todoelmondo(Ray Mahoney)
, but it looks like a list of > numbers folllows this, and not the letter A I'm converned this is > perhaps a special, at an odd freqency, and not the standard 10MHz > 10811A. Is there any where it actually says 10811A on the > package? Can you give me a price to ship to the UK. Address would All 10811's of any flavor have 10 MHz outputs. (Except an extremely small number of prototypes at 10.23 MHz for a GPS initiative that were never released AFAIK). If you know anything about making an SC cut crystal of the quality of the 10811, you would know that changing the frequency requires a huge R&D investment, way beyond what any special could justify. There are basically only three models of 10811 made: 1) With PC edge connector 2) With coax connectors 3) Special for the 5071A with extended tuning range, which is unlikely to show up for sale. All 10811-6 are simply selections of one of the above. After a lot of time has gone by, these selections are, for the most part, irrelevant. "Model 10811A" is a nomenclature used in cases where an oscillator was sold directly to the end user as a component. HP was briefly in the merchant oscillator business. The vast majority of 10811's were for internal use. They all have 10811-6 numbers. Many of the 10811-6 numbers are selected to meet tighter specs than the 10811A spec. There is nothing superior about an oscillator labeled "10811A". BTW, it was superceded years ago by the 10811D/E, in terms of model numbers. Rick Karlquist R&D Engineer at HP Santa Clara Division 1979-1998 ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
