[evlatests] Antenna 21

[Barry Clark]

I set the delays for X and L bands.  They were not as far out as Rick 
reported last week; I suspect that resetting the D30x's brought them into
a more reasonable state.

I optimized the focus at L band.

IFs BD remain less sensitive than they should be.

IFs AC are a large factor less sensitive than they should be.  In addition,
IF C is rather twitchy.  That is, adjacent 10 second integrations often 
differ by 10-20%.  One suspects that is due to a more egregious twitchiness
at a timescale less than 10 seconds.

At K band, fringes were barely detectable on IFs BD, and not at all on
IFs AC.  I suspect that we may be peaking up on a sidelobe.  I spent a 
few minutes looking around for a stronger response, and didn't find one.

I had a quick look at Antenna 26 Q band.  We aren't getting enough power
back.