[evlatests] Ant 24

[Rob Long]

Ant 24 did have water both on the tops of the racks and inside the 
racks.  The FC optical connectors on the Utility rack (formerly known as 
the FE rack) have a light layer of rust on them.  The water leaked past 
the seams in the top of the racks, ran down the corner, and puddled in 
the rail at the bottom of the rack.  The Utility rack had significantly 
more water than the LO rack, but neither rack had gotten water in any 
critical places!  All modules and power distribution were dry and happy. 
  The mechanics believe that they sealed the leaks, but we went ahead 
and cleaned and dried the top of the racks and put aluminum tape over 
the seams.

We checked the other EVLA antennas (except for 16) and everything looked 
dry.  The road to 16 was a giant mud puddle, so we decided not to try 
and get stuck at 4:00 in the afternoon!

The L302-1 in ant 24 will not lock even after several reboots and power 
cycles.  We did not get the chance to pull the module as we found this 
problem late in the day and were in the midst of another thunderstorm.

We worked on ant 13 for quite a while trying to understand why the DTS 
modules (and the L302-1) were all incommunicado.  I tried forcing power 
glitches to the electronics (with battery backup on-line) and could not 
break anything.  I wonder if the DTS modules react more adversely to a 
power surge than a power dip(?)  After power cycling the 5 modules 
mentioned above, no amount of 'fiddling' with power would cause them to 
lose communication.

Rob