[evlatests] this morning's stress test

[Rick Perley]

    The erratic behavior of antenna 4 needs to be emphasized.  
Emmanuel's test this morning apparently caught it in an 'on' state.  I 
have extensive observations -- over many days -- showing that it is 
fundamentally unstable at most bands.
    Note that at L-band, both antennas 3 and 4 seem to be working well ...



Emmanuel Momjian wrote:
> A summary of this morning's stress test:
>
> P-band: very weak fringes on antennas 3 and 21, and no fringes on 
> antennas 1, 4, 5, 15, 16.
>
> L-band: All look good.
>
> C-band: Antenna 3 is in very bad shape, its effective Tsys, depending on 
> the IF, is at least 1500 K and as high as 3000 K.
>         Antenna 4 is ok during the ~1 minute C-band scan of the stress test.
>         Antenna 18 is ok.
>
> X-band: no fringes on antenna 3, antenna 4 is ok (in a ~1 minute Xband 
> scan).
>
> K-band: no fringes on antenna 3, antenna 4 is ok (in a ~1 minute K-band 
> scan).
>         Antenna 2, IF B only is less sensitive by a factor of 2.
>         Antenna 5 is less sensitive by a factor of 2 in all its IFs.
>
> Q-band: no fringes on antennas 3, antenna 4 is ok (in a ~1 minute Q-band 
> scan).
>
> Emmanuel
>
> Rick Perley wrote:
>   
>>     I ran tests yesterday noon, at all bands.  A quick summary of 
>> performance, by band.  Antenna 25 was out of the array.  All others were 
>> pointing. 
>>
>>     1)  P-Band.  No fringes from 1, 3, 4, 5, 15, 16, or 21. 
>>
>>     2) L-Band.  All antennas o.k. 
>>
>>     3)  C-Band.  3 gives weak fringes.  18 gives only noise.  4 is 
>> erratic -- good some times, no fringes other times. 
>>
>>     4) X-Band.  3 weak, 4 and 18 are erratic.  5 is erratic on IFs B and 
>> D. 
>>
>>     5) K-Band.  3 weak, 4 erratic (good fringes some sources, no fringes 
>> on others). 
>>
>>     6) Q-Band.  3 and 4 both weak (or no fringes -- hard to tell at this 
>> frequency with the sources I had). 
>>
>>     A stress test was run this morning -- Emmanuel should be able to 
>> report on its results shortly.
>>
>>
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>
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