[time-nuts] SRS SR620 External Source Issue -- Help Request

[Magnus Danielson]

From: <TheInfamousFlavio at hotmail.com>
Subject: Re: [time-nuts] SRS SR620 External Source Issue -- Help Request
Date: Wed, 21 Feb 2007 18:13:08 -0500
Message-ID: <BAY128-DAV1276324C601CA50F907B42A9880 at phx.gbl>

> I've done the self calibration. Nothing changes.  I've let everything 
> warm-up and checked both channels A and B, same thing.  I've swapped the 
> cables on the front and the back, same thing.  I've tried a T-connector on 
> the ref input with 50ohm termination, same thing.
> 
> The readings are pretty stable, they are just offset by -0.0015 Hz.

Hmm. Interestingly enought I've seen something similar on a HP5372A where the
A channel was slightly low on the frequency but not the B channel. I have not
investigated that in detail to make any conclusions but that 5372A may be in
for a slight trim-up. Since it's interpolators allow for "interesting" trimming
of each interpolator step it would be interesting to see if I could trim it in
and out of frequency!

Now, if the interpolator trimming is the culprit, I need to wrap my head around
on how it turns out as a frequency error.

I'll check it again tomorrow, as I use it daily right now.

I don't have the manuals (and particular the service manual) for the SR620,
does anybody have them in electronics form?

Cheers,
Magnus