[time-nuts] HP Z3817A Reverse Engineering
Ed Palmer
ed_palmer at sasktel.net
Sun Oct 27 20:54:09 UTC 2013
Hi David,
Skip Withrow and I were able to figure out the connections and the basic
operational features. I've attached a document that describes our findings.
I wouldn't mind picking up another E1938 oscillator, but I'm reluctant
to buy one that might have mismatched oscillator and circuit board (i.e.
the serial numbers don't match). I've asked a couple of vendors if the
serial numbers matched, but they won't respond. Does anyone have any
experience with a mismatched combination? How's their performance?
Ed
On 10/27/2013 1:26 PM, David Hooke wrote:
>
> Hi Ed,
>
> My E1938 also came from a very battered STLN4096A from the same
> source, and I might also try to get the other boards functional. Could
> you share the details of the GPS connections, and which GPS receiver
> you used?
>
> Cheers,
>
> david
>
>> I recently purchased a Motorola STLN4096A with the HP E1938A
>> oscillator. I bought it for the oscillator only.
>>
>> Then I got intrigued by the HP Z3817A GPSDO that's included. I've
>> reverse engineered most of it and I've got it running. The 1 PPS is
>> really good ( 1000 measurements, Std. Dev. of <200 ps, min to max
>> range of <1.5 ns) and the HUP is very slowly dropping (currently at
>> 13 us after ~1.5 days) as the oscillator works out the kinks after
>> it's long sleep. It's dropping much slower than my Z3801A did when I
>> first turned it on.
>>
>> There's one input that I haven't been able to figure out. I've got
>> data in and 1 PPS in from the GPS receiver. Everything seems to be
>> working so I'm at a loss what that the other input could be for.
>> There are no clues to it's function because it appears to go into one
>> of the Xilinx chips.
>>
>> Does anyone have any more info on the unit? Has anyone figured out
>> the other input?
>>
>> I have searched the net and the archives. There's very little info
>> or discussion on this unit.
>>
>> Ed
>>
>>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>
>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Z3817A Connection Info.rtf
Type: application/msword
Size: 3723 bytes
Desc: not available
URL: <http://febo.com/pipermail/time-nuts_lists.febo.com/attachments/20131027/ca8a14aa/attachment.dot>
More information about the Time-nuts_lists.febo.com
mailing list