[evlatests] Integrated Feed/Receiver Test - Day 1

[Bob Hayward]

Both L-Band receivers (S/N 1 & 2) passed their leak checks and cooled 
over the weekend. S/N 2, which has a dead LNA, but was sent to Cryo for 
evaluation of the thermal effects of having a second Model 350 fridge on 
the same helium line, cooled fine (OMT down to 63K). S/N 1, the receiver 
being used for the integrated feed test only got down to 78K, and this 
after getting a new fridge (the original had moisture contamination). So 
that is disappointing. It got down to about 70 when S/N 2 was turned 
off. We may have to live with this receiver running high for the time 
being (back in the lab it originally cooled to the low 60's and then 
slowly started climbing into the 70's).

Over at the Barn, the gantry crane was brought to the front and the hook 
was lower to hoist the L-Band feed. Then it died. Totally. No motion at 
all in any direction. The electricians spent  much of the afternoon 
investigating the problem. No easy feat since they have to be hoisted by 
the cheery picker all the way to the top (105 ft or so). We had hoped to 
mount the receiver in the afternoon and do some preliminary tests (RFI, 
spot Y-factors, etc.) while the receiver was re-cooling after being 
moved over from the Cryo Lab.

So we have a bit of a delay. The receiver is in the Barn now - hopefully 
still cold - waiting for the hoist to become operational again. Keep 
your fingers crossed...