[evlatests] Tests, June 27 2006

[Ken Sowinski]

Rick has already reported on the L302 amplitude dropout
tests.  Jim and Matt reprogrammed the FPGAs in both
L302s in antenna 13 and we expected that there would
be no amplitude dropouts.  This was not the case and
the behavior was might be best termed bizarre.  The
most telling result is that there were sometimes
dropouts seen in antenna 24.  We will have to think
of ways to test Jim's suspicions.


A 3 dB tracking test was attempted again.  A pointing
solutions for a coule of the antennas show unusual
residuals and it is worth doing this test to rule it
out as a contribution to the bad pointing.


Some time was spend trying to get the new bands on
antenna 18 working.

K band
Still no coherent correlated data.  There are still
impulsize bursts seen in the SD at the level of a
few tens of per cent.  The sampler RMS, TP and ALC
are all stable, suggesting that there is noise in
the signals which is changing on a timescale rather
shorter than a second.

Q band
AC give no coherent signal.  The l302-1 claims that
it is in lock, and AC works at X and L bands.
BD works fairly well.  Pointing was gotten about right
and focus and delays were set.

My guess is that there are still problems in the UX
converter.  One way to test this is to connect K band
directly to the bandswitch, bypassing the UX converter.
Unless inspection of the T303 showsup problems this
would seem to be the next step when someone feels up
to it.