[evlatests] P-band checkup

[Paul Harden]

Made some low band progress at the site on Thursday.

On 7/11/2016 7:49 PM, Rick Perley wrote:
> 1) All antennas *except* ea08Y worked well.  The sensitivity of this 
> polarization channel is less than half of the others.

We fixed this low band antenna.  A bad connector-adapter gobbling up the 
power on the RCP side.  Bandpass plots shows all IF's now at proper 
power and passbands.

> 4) Very large cross-polarizations are seen on some antennas.
>
>          a) The worst (by far) are:  ea01,ea06, ea08, ea17, ea27. 
> (ea01 is nearly 50% cross-polarized!!!).
EA08 alignment looks pretty good.  Nothing really to realign.
EA01 indeed was misaligned by about 30 deg.  Dan Mertely and Brandon got 
it realigned and reported the mounting hardware was all tight with the 
new mounting collar and no real explanation on why it had moved so far.  
We'll see what happens over the next few months.  At the moment anyway, 
it is properly aligned to the quadrapod legs.

We didn't get a chance to check P-band dipole alignments on EA06, 17 or 
27.  Will catch next maintenance day.

Also worked on the no CAL switching on EA01.  Problem is the CAL term 
from the F318 to the low band system is switching at 20Hz vs. 10Hz.  Put 
in a new F318, no change, so obviously an input problem somewhere.  Jim 
Jackson thinks he knows what the problem might be in the fiber 
interface, so will likely be fixed very soon.

Paul, Sandra, Dan, and Brandon
The Low Band Brigade, San Augustin Chapter