[evlatests] ea13 status: revised

[Wes Grammer]

Ben and Dan had a look under the feed radome today on the K-band RX in 
ea13, and found a lot of water collected at the bottom, right against 
the window. They've drained it out, and are drying the feed as best they 
can. We need a test to confirm it, but it's highly likely we've found 
the culprit.

It's a bit surprising there was so much water in it, as the receiver was 
installed on July 29, the day before it went out on the master pad. Ben 
is looking into whether the radome material and/or retaining ring need 
to be replaced.

Thanks to Dan Mertely for his assistance to Ben today at ea13!

-Wes

On 8/7/2014 11:14 AM, Ken Sowinski wrote:
> On Wed, 6 Aug 2014, Ken Sowinski wrote:
>
>> All receivers are now installed.  All work except for K band
>> which does not fringe at all.  It behaves as if the horn were
>> not connected to the sky.
>
> Allthe high frequency feeds were alignedand braced this morning.
> Ka and Q band still look fine.  K band, however is still dead
> in the sense of no fringes.
>
> I pointed the array at the Sun while at K band and ea13 showed
> no change inTP while other antennas increased by 20 dB or so.
> Is it possible that the feed cover was never removed?
>
>
> Another, independent, problem is that the power into the T304
> for IF B, and only IF B, is much to low when setup at K, Ka
> and Q bands, but not at Ku band.  In these tests the direct
> path was used for both IF pairs at K band and higher.  Looks
> like a problem in the T303.
>
> Ken\
>
> _______________________________________________
> evlatests mailing list
> evlatests at listmgr.nrao.edu
> https://listmgr.nrao.edu/mailman/listinfo/evlatests
>