[evlatests] antenna 16 phase switching

[Ken Sowinski]

Jim and I discussed this and I realized that the problem had
to be in the MIB heartbeat timing rather than the heartbeat
feed to the L302 innards.  The reason for this is that it is
the MIB that stuffes in the phase switching offset in the 
heartbeat interrupt routine.

At the antenna Jim asnd Jerry found that almost all the timing
references out of the L305 were not up to par.  They were able to
wire up good signals to the L302s and suggested I try it.

Late in the afternoon there was an opportunity.  When pointed
IFs B and D worked, weakly at L band, but not A and C.  I tried 
with and without phase switching and the amplitude did not change;
that problem is taken care of.  During the time of this test
the BD phases at L band seem stable at 10 second integrations.

I tried C and X band.  No luck with any IF.   End of day.


I report that the dataset in the D rack for antenna 16 seems
to like to make command parity errors.  So much so that commands
to the filters never get through.  This should be repaired
before Thursday when we have hopes of doing more work.