[evlatests] Low band work

[Paul Harden]

Dan Mertely and myself fixed three antennas yesterday with low band 
problems.

EA09 and 11, with sensitivity (weak fringes) and CAL switching problems, 
were fixed with new style receivers and Interface Boards (that 
conditions the CAL signal).

EA25 was fixed that has had a lingering problem with weak RCP signals, 
though the receiver is OK.  Checking every connector in the system, we 
finally found a right angle adapter on a heliax run with about a half 
teaspoon of water & ice in it!  We now know water attenuates P-band at 
least 30dB.

Thus, EA09, 11, and 25 should be ready for use.  Dan and I will replace 
the receivers and install new CAL boards on EA07 and EA19 next.

Receiver status table has been updated
http://www.aoc.nrao.edu/~pharden/LBR/lbr.htm

Paul and Dan