[evlatests] EVLA Hardware

Rob Long rlong at nrao.edu
Wed Aug 22 19:39:25 EDT 2007


Ant 11 was fringing nicely a 4:00 PM today except for IF-A.  We reset 
the DTS (even though all backend values looked normal) and IF-A 
amplitudes came right up to normal!  Hmmm....

Ant 14 fringed fine at L-band sysstart today.  I know 14 worked fine at 
L-band yesterday so I'm not sure what happened overnight.  I'll dig 
through the archive and see what I find.  Also, ant 14 does not 
autostow.  We disconnected the fiber from the ACU MIB initially and 
waited for over 45 minutes.  We wondered if the MIB was continuing to 
send the same position to the ACU, so we reconnected the fiber and 
disconnected J-7 on the back of the ACU.  After another 25 minutes, it 
still wouldn't autostow.  Hmmmm again....

We looked at ant 21 C-band IF-A and definitely saw low gain.  (We 
actually saw low gain on A and B.)  When we started disconnecting cables 
to make measurements, everything looked good.  We hooked RCP and LCP 
back up to C-band and lo and behold, all levels looked fine!

Rob




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