[evlatests] P-band status

[Frank Schinzel]

On 09/22/2017 10:55 AM, Rick Perley wrote:
>     Some P-band data were taken earlier this week. Frank asked me to 
> check on the quality:
>
>     I extracted the four scans of 3C147, and used five spectral 
> windows (5 through 9).  I find:
>
>     1) Antenna 28 was in the barn, and antennas 13 and 14 were both 
> out of service during these observations.
>
>     2) Antenna 23 was in a peculiar state -- the 'Y' channel 
> oscillated in delay on a fast (few seconds) timescale.  The 'X' 
> channel also had irregular delays, but only for the first two 
> calibrator scans -- it seemed fine for the last two (two hours later).
>
This is probably a DTS issue. It has been doing funny things.
>
>     3) Requantizers seemed to be working (meaning, they changed level 
> between the second and third calibrator observation).
>
>     4) CALIB gains (after applying the RQ correction) showed a wide 
> range of antenna correlated power -- a factor of four between highest 
> and lowest for a given SPW.
>
>     5) The 3 MHz bandpass ripple is strong on:  7X (2dB, pk-pk in 
> power), and 17X (2 dB).  All others are less than 1dB.
>
>     6) With respect to 'golden antenna 24', the cross-polarization is 
> high (above 10%) on:  ea03, ea10, ea14, ea16, ea17, ea18, ea19, ea21, 
> ea22, ea27.  These are likely to to dipole orientation.  A 
> confirmation check would be useful.
>
Note ea24 DTS was flaky when the data was taken, if you don't see 
anything crazy in the phases or delays then it might have been ok.
>
>     Rick
>
> _______________________________________________
> evlatests mailing list
> evlatests at listmgr.nrao.edu
> https://listmgr.nrao.edu/mailman/listinfo/evlatests