[evlatests] Results of solar 20-db test

[Ken Sowinski]

On Mon, 28 Mar 2011, Rick Perley wrote:

>    Not all is rosy, however.  The algorithm which decides how the T304 
> attenuators are adjusted to maintain proper signal levels to the 
> samplers (and avoids saturation within the module) is clearly 
> inefficient, and makes very strange choices for many antennas.

We should do this again with the type which affected L band corrected
to try to see what it might be doing wrong.

> The switched power (PDif) values while on the sun are biased negative -- 
> they should be noisy with a zero mean, or at most a very slight positive 
> mean.

To try to understand this we should look at P_diff with the
noise tubes turned off.