[time-nuts] Symmetricom SA.35M Information Request
Ed Palmer
ed_palmer at sasktel.net
Wed Mar 16 06:11:16 UTC 2016
Hi Magnus,
Yes, the 10 MHz output sweeps about +114 and -168 Hz. The 6.834 GHz is
moving +84 to -107 KHz. Not the same ratio, but close enough. So the RF
side all looks good. Good thing too since this thing is much too small
to have any trimmers. I haven't even found the VCXO. I think it must
be on the bottom of the board.
I got a copy of the Designer's Guide from a kind soul (Thank you
again!). It makes one cryptic mention of a Parameter Recovery mode that
could result in a 2 hour lock time. I let it run and logged the
result. It tries really hard to get a lock! It spent 3 hours tweaking
parameters for the laser trying to get a lock before it gave up. The
results look like it might have actually been successful at setting the
laser parameters so I'm moving on to the detector side. I haven't found
the detector yet so I haven't looked for any modulation. I have to
reread some documents I found. I don't think this laser-based unit uses
the typical modulation scheme.
I'm doing a lot of reading between the lines and plain-old guessing.
Lots of fun! :)
I've temporarily set it aside to help a guy try to resurrect an
FTS-4040A Cesium. Is that a dead STEL-1173 I smell? We haven't got to
that point yet, but it's on my radar!
Ed
On 2016-03-15 8:02 PM, Magnus Danielson wrote:
> Ed, On 03/14/2016 10:10 PM, Ed Palmer wrote:
>> >Does anyone have any info on the Symmetricom SA.35M Miniature Rb
>> >Standard? I have the data sheet, patent document and the MACDEMO
>> >program. Is there anything else available? For example, I'd like some
>> >more explanation of the various parameters read by the MACDEMO program.
>> >
>> >I have a sick unit that I'm exploring. It won't lock. The VCXO is
>> >sweeping and I've confirmed the presence of the 6.834 GHz RF signal so
>> >I'm now looking towards the laser.
>> >
>> >I don't expect that I'll be able to get it working, but it's fun to play
>> >with.
> Does the VCXO sweep over the right frequencies. Does it cross 10 MHz?
>
> Can you see any status for fundamental and second overtone responses?
>
> Can you measure from the detector?
>
> Cheers,
> Magnus
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