[evlatests] Fringe tests of revised T304 module Dec 14, 2005

[Mark Claussen]

Yesterday, Rob and Jerry installed the T304 module with
cascading filters (to make something that has the same
effect as a bandpass filter) in order to eliminate the
aliasing problem (producing closure errors) at C band 
(and other wide band receiver systems).  This T304 module
was installed in Antenna 16, on IF B.  Ken S.  took a
quick look yesterday afternoon to make sure that delays
and power levels were ok, in preparation for some test
time that we had early this morning.  

I used part of that time to observe at C band (with the
normal L301 settings, where the closure/aliasing effect
could easily be seen).  The quick result is that the
closure error on the 14-16 baseline is gone (or at least
much reduced) on IF B as compared to A,C and D, as expected.

I have posted some plots to this effect on

http://www.aoc.nrao.edu/evla-internal/techdoncs/testresults/20051214.mc


Mark