[evlatests] EDFA Status

[Jim Jackson]

JDSU came back with an estimate of 8 weeks for a new unit and 4 weeks 
to repair an existing unit. Their sales rep is looking for a loaner 
unit. We are pursuing all of these options but obviously that's a 
long time for the array to be down.

We have now patched around the EDFA's to see what we get.  Rob and 
Mike were able to tweak on the deformatters and got most of the 
antennas working.  There are various amounts of data errors occurring 
on the DTS links but they should be sufficiently small as to have a 
minimal effect on data.  I believe they said they had a total of 24 
antennas (EVLA and VLA) functioning. This will be an interesting test 
of how low levels of data errors affect scientific data quality.

Additionally, I decided to dig into the older EDFA controllers and 
attempt to repair them at the component level with no 
documentation.  After some reverse engineering, I discovered the same 
burnt chip on both controller boards. I just placed an order to 
Digikey for these chips and every type of chip I can find connected 
to them in the circuit.  These should be here early in the 
week.  Hopefully, I can get at least one unit working with these 
parts. For $60 in parts and a few days work, it's worth a try.

Jim Jackson