[evlatests] Antennas 4 and 24, plus antenna efficiency.

[Rob Long]

Rick Perley wrote:
>     Reviewing the spectral line data, some more information on 4-band 
> antennas:
> 
>     Antenna 24 has a warped bandpass on all IFs, particularly in IF A.  
> The signal is very weak, although I think the polarization is correct. 

Ant 24 has hardware problems that need further investigation.
> 
>     Antenna 4 has a strongly sloped bandpass shape on IFs B and D only.  
> IF 'D' is especially notable -- the lower 1/3 of the bandpass has no 
> source spectral power at all. 

Ant 4 also needs to have T304 levels set.

Rob