[evlatests] EVLA Antenna work today

[Jim Jackson]

Here's an update on what was done to Antennas 13, 14 and 16 today  (2/28).

Antenna 13 IF's A and C - The MIB in the L301-1 was in a strange 
state.  There was no output from the module and you could ping the MIB but 
not log into it.  Cycling the power seemed to fix it.

Antenna 13's L302's were both reprogrammed with new MIB code at least once 
to address timing issues.  We had to reboot them once.  I'll let Ken, Barry 
and Pete report further.

Antenna 13 L-Band RCP - The heliax cable on the output of the receiver was 
loose to the point where we were amazed it had been working at all. It has 
been tightened.

Antenna 14 IF B Intermittent loss of power - The cable from the correlator 
room wall bulkhead panel to the D-Rack is broken. Lee is making a 
replacement as I write this and it will be installed tomorrow.

Antenna 16 - The D351-a deformatter module seemed to be running but I could 
not communicate with the CMIB (it did answer to pings however).  Cycling 
the power seemed to fix it.

The other problems reported by Ken and Rick with 14C, 14D and 16B - These 
all appear to be problems with the levels as set by the scripts. Many of 
the T304's have been swapped out over the last month to have their 
motherboards replaced.  Someone needs to recalculate the required 
attenuator settings as stored in whatever tables the scripts use to set 
them up for each band. 14D in particular ends up set for 6-8dB higher 
output than it should be. I suspect the unit in there when the values were 
originally calculated was not actually setting it's attenuators correctly 
and the new one is. The last unit to be replaced is 13D - Donna is doing 
that tomorrow.

Round Trip Phase - Tom determined that we have sufficient fiber to split 
the return fiber from Antenna 13 and run it back on two fibers. We do not 
have enough fiber patched for two runs out to the antenna.  We forgot that 
we needed the second L353 to receive the second optical signal and left it 
in the AOC lab.  It will be taken out and installed tomorrow.

Jim