[evlatests] slow attenuator setting on ea16 IF D

[Claire Chandler]

Yes, all other IFs look like ea15 and ea17 in the plot.  This only affects 
IF D.

Claire

On Mon, 8 Aug 2011, Ken Sowinski wrote:

> On Mon, 8 Aug 2011, Claire Chandler wrote:
>
>>  Steps in the amplitudes on ea16 IF D (L-pol) indicate that it's taking
>>  several minutes to find the correct attenuator setting at the beginning of
>>  an observation (the attached plot is for Ka-band).  I have seen this in
>>  several recent datasets; the attached is from July 15, but I also saw it
>>  in data taken on Sunday morning.
>
> I hesitate to blame mis-set attenuators for this because the
> steps are not consistently 1 dB or multiples.  If it were not
> for the fact that the other IFs were fine (is that really true?)
> I would consider a sticky subreflector that moves a little further
> each time it is commanded until it finally gets there.
>