[evlatests] antenna 18, L band

[Ken Sowinski]

It was reported that the T302 and M301 were installed and
working.  They sort of work.

Subreflector settings were added to the parameter database.
And delays were set about right.  Suitable attenuator setting
for IFs A to C are:
RF  0  0  0
IF 15 12 15
IF D is not working well enough to know where to set the
attenuators.

Assuming the the band switches are wired to the M301, the
M301 appears to be able to switch between X and L bands.

Only IF A works properly.  IF D is putting lots of signal
into the sampler and it does not change when downconverter
attenuators are changed.  IF D is broken at X band as well,
so I suspect the downconverter or DTS module.

IFs B and C are weak.  The polarizations are swapped in
a funny way:
      RR   LL   RL   LR
AC   1.6  0.3  1.9  0.3
BD   0.3  xxx  xxx  1.9
There must be some funny wiring errors.

If anyone wants to visit the antenna I will be happy to
stow it.