[evlatests] ea21

[Eric Chavez]

All LO/IF items have been addressed from the inspection report. There 
was a few wiring issues on the U/X converter and they are now fixed. The 
sub-reflector has been fixed by Servo, and the D301 has been swapped a 
third time. There is still a small issue which doesn't seem to affect 
data. The ripple on X-band LCP was repaired by the front end.

Jerry and myself ran maintenance scripts on all receivers which all had 
acceptable bandpass plots.

T304b needs to be swapped sometime in the future because of excessive 
ripple, it is not horrible but it could be better. We only have one good 
spare on the shelf at this time so we decided not to swap it.

Eric

Ken Sowinski wrote:
> On Mon, 11 Jul 2011, Steven Durand wrote:
> 
>> There are parity errors on IFa and the bandpass plot looks like
>> a comb generator.
>>
>> I can only confirm the the C-band receiver is cold.  IFs b,c
>> look OK.  D has a lot of roll off.
> 
> A progress report.  I tried to make it work today.
> 
> Fringes were obtained at S band and the polarizations are
> the right way around.  However there is still an FRM foucs
> drive problem and the focus is many centimeters off.
> 
> C band was tried, but there is a (known, I think) problem
> with the receiver.  Higher frequencies are hopeless until
> the subreflector is fixed.
> 
> The IF A DTS system was working when I did this, but Jim thinks
> it might not yet be very stable.
> 
> Tomorrow is another day.
> 
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