[evlatests] T304 attenuator changes

[Ken Sowinski]

On Fri, 19 Jun 2009, Bob Hayward wrote:

> Are any of the LOs (i.e., L301 or L302) happening to change between
> scans? This might not cause T304 to change its attenuator setting but
> even a small LO change could cause the output signal from the various
> mixers to change slightly. Depending on the amount of input gain slope
> or ripple, the resulting bandpass could look quite different.

Rick can correct me if I have this wrong.

The sequence was alternating scans at C and X band, but all the
C band scans were at the same tuning as were all the X band scans.
Synthesizers retuned at each band switch, but always returned to
the original frequency for that band.  I think that the L301s are
sent a command even at X band, so that they as well as the L302s
are retuned at each band change.