[time-nuts] Re: HP 10811-60111 Oscillators {External}

[Jim Muehlberg]

Bob, so the ADEV gets better than factory spec - better over time?  The 
number stated below approaches NIST_F1 at 1s ~2.8E-13. (Not sure if its 
correct - found on a slide presentation) and apparently exceeds most 
commercial cesium clocks for time scales less than~10s..

This is all fascinating since I now have two functional (as far as I 
know) opt 4 5061As (with, of course, 10811s inside). Plotting the spec 
for the 10811 and the 5061 in time lab is interesting, as the ADEV for 
the 10811A does indeed  exceed the 5061 for time scales less than 1s.

Maybe this is old news to all of you, but it's more than I knew yesterday!

Jim


On 2023-01-10 8:57 AM, Bob Camp via time-nuts wrote:
> Hi
>
> There’s a seller on eBay ( besttestus ) who comes up with batches of 10811’s from who
> knows where. Some are still attached to option boards for instruments. They just sold out
> of the latest batch of about 200 or so. I’d guess they will get some back in eventually.
> Asking price is typically right around $50 or so (with free shipping). They take offers so
> you can indeed get them to sell you 10 at a whack for around $42 each.
>
> Based on testing more than a few of them, there will be a couple that have significant
> issues ( < 5%). There will be some that are in spec, but not by as much as when they
> left the factory ( maybe another 5 %). The rest split into “pretty good” and “really good”.
>
> The fact that the really good ones are still in the group suggests that these are indeed
> NOS or something like that. A lot of batches you see have the best of the best pulled out
> and you are just buying “the rest”. I’d guess that Fair is in the same mode, you get the
> whole lot and can sort time as you wish.
>
> Just how many show up in the sub 6x10^-13 ADEV range varies a bit by lot. To me,
> anything that’s in the parts in 10^-13 counts as very good. How many would improve
> if you burned them in for six months or so, who knows….
>
> Bottom line: You probably do better buying closer to the source of the surplus in a
> case like this.
>
> Bob
>
>> On Jan 9, 2023, at 4:18 PM, DM via time-nuts <time-nuts at lists.febo.com> wrote:
>>
>> To All,
>> Just a quick heads-up to anyone who might be needing, or just want one for fiddling with, Fair Radio Sales has a fair stock and a pretty good price for the HP 10811-60111 ovenized oscillators (https://fairradio.com/product/10811-60111/) . They are selling them (including the 05328-20027 support assembly) for US $79.00 each.
>> Both I have bought two of them and both arrived in like new condition, and were fully operational, and required only minor tweaking to bring them to 10.0000000 MHz after running for a couple of months. The attached 05328-20027 support board indicates that they were removed from the HP 5328A or 5328B counters.
>> Seems to be a pretty good deal for these well-aged oscillators.
>>
>> BTW, Fair Radio is also offering the 10544A oscillators for US $69.00. Both are described as "Tested for output may need adjustment."
>>
>> Cheers,
>> DaveM
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-- 

Jim Muehlberg
Senior Engineer

National Radio Astronomy Observatory
ngVLA Local Oscillator Lead

1180 Boxwood Estates Rd B-111
Charlottesville, VA 22903-4602
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C 434.422.2017