[evlatests] Antenna 21 status

[Jim Jackson]

Antenna 21 should now have working P, L, X and K bands.  Only X-band has 
valid entries for the IF B/D T304 attenuator settings, so someone will need 
to take care of that for the other bands.  I think that applies to all four 
IF's at P-band.

The problem with X-band was tracked down to two separate problems. LCP was 
dead due to a heliax cable connector that came apart at the 
receiver.  There was no switched power on either polarization due to a 
loose DB-25 connector at the receiver.  The output levels from this 
receiver are still a little low.  Sampler RMS is 6.5/7.5 on IF's A/C with 
T304 attenuators all set to 0.  This should work ok but is marginal.

Jim