[time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812...

[Charles Steinmetz]

Bob wrote:

>The 58503 is a Z3801 with a pretty instrument style package put 
>around it - right?
>
>If so, it might / should  have a 10811 in it rather than an MTI OCXO.

I think there may be other minor differences between the 58503 and 
the Z3801, including a newer GPS engine, but I'm not positive what 
they all are.  They are clearly very similar.

The 58503 should have either a dual-oven 10811 or the Symmetricom 
look-alike.  (The Symmetricom has a 5MHz crystal and a doubler -- it 
looks exactly like a DO 10811 except for lacking an HP sticker.)  I 
bought a 58503 from one of the usual far-eastern suspects, which was 
advertised expressly as having a 10811.  When it arrived, I saw that 
it had the Symmetricom OCXO.  I fired off a message to the supplier 
complaining that I did not receive the promised 10811, and he offered 
to part-refund the purchase price or exchange the 
oscillator.  Because of the high transaction cost of exchanging, I 
elected to take the part refund thinking I would swap in one of the 
DO 10811s I had on hand.  But after only a week of running, the 
Symmetricom was better than all of the 10811s I own!  (Interestingly, 
my best 10811 is not a DO unit -- it is a SO 10811 that came out of 
an HP5345A that was originally part of a 5390A frequency stability analyzer.)

Note:  My experience should NOT be read as a claim that the 
Symmetricom oscillators are better than 10811s.  My sample of the 
Symmetricoms is way too limited to make any claims.  But this 
particular Symmetricom happens to be a very fine OCXO.

Best regards,

Charles