[evlatests] P band

[Ken Sowinski]

On Mon, 9 Jul 2007, Rob Long wrote:

> Since I know you guys are bored with nothing to do, I wanted to let you know 
> that Ant 24's P-band problem on IFs B/D are due to no T304 attenuator values 
> loaded in the LUT.  When I ran P-band maint script today, the attenuators 
> showed values of -1 and -1.  After setting the T304 attenuators manually, I 
> saw good levels at P-band.  (I obviously don't know about fringes yet.)
>
> Ant 26 is being complained about in the same way, but the antenna was being 
> used so I could not set it up at P-band.  You may want to take a look at this 
> antenna also.

I have entered attenuator settings for BD for antennas 24 and 26.
They will get noticed the next time the executor is restarted.

Antennna 23
Rick has reported strnage fluctuating amplitudes.  This is because
the SD voltages are all 0.0 at P band and the T-sys correction is
going awry.

Antenna 24
Seems to have a different distribution of power between the P band
bandpass and the full bandpass presented to the T304 than most
other antennas.  If the attenuators are set for a reasonable
sampler RMS, then the T5s are overdriven even when the deformatter
gain parameter is reduced to 15.

Antenna 26
SD voltage for RCP is only about 0.3 V.
There seems to be some difference between AC and BD IF pairs.
For comparable sampler RMS settings the AC T5s are getting
a little too much pwer, the BD T5s a little too little power.


Except for antenna 23 I did not look at any correlated P band
signals.


It might be about time to set up the array at P band and
systematically record all the sampler spectra to see where
we stand now compared to a month ago when this was last done.