[time-nuts] HP10811 dual oven
pete at petelancashire.com
Tue Aug 4 21:53:28 EDT 2015
When I made the offer for the unit, I took the chance that it might be, I
saw that the s/n was 3505A02095, the same HP prefix
on my other dead dual oven 10811.
When I got it, my luck won this time, one of the coax cables is tagged 10
MHz and the other EFC.
A bit of background
The modules came from an HP system that was built for generating the master
T1/E1 clock in a central office. Some chassis
had 64 x 2.048 MHz outputs !
I chatted with the seller, The system he got took up 2 rack bays, It had
128 ouputs, and it had a HP 5071A as the primary clock. Later version are
the ones used a GPS receiver.
I don't think many people know about the 55400A, they more then likely
didn't build many. I only read about it when this thing came up for sale.
My guess is there will not be a flood of them on the surplus market. And
sadly think of all the 5071A that more then likely ended up in a
On Tue, Aug 4, 2015 at 2:24 PM, Charles Steinmetz <csteinmetz at yandex.com>
> Pete wrote:
> I have a HP / Symmetricom unit that has a dual oven 10811 that was part of
>> a telecom master clock distribution system that was only meant to run in a
>> controlled environment.
> I'm not 100% positive, but I believe the OCXO in your photos is not an HP
> 10811, but rather the Symmetricom version, which uses a 5MHz crystal and a
> frequency doubler. I bought a 58503 that the seller guaranteed had a
> 10811, but it turned out to have the Symmetricom oscillator instead. When
> I pointed this out, the seller offered to refund me the price of a DO
> 10811, which I accepted. Just for curiosity's sake, I ran the 58503 as it
> was, and after a time it settled into being one of my most stable OCXOs --
> better than all of my 10811s.
> Best regards,
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