[evlatests] Ant 21 Status

[Michael LeBlanc]

To all,

2 issues were found 03/08.

1. 9.6 timing to F14 LEDs erratic.
2. No timing reported @ all D301-4 modules.

Item 1.

Swapped 9.6 Receiver card from VLA spares. The LEDs on the F14 still 
erratic. Measured voltages @  PDB. All voltage within spec, but the +7 
was changing from 7.15 to 7.29 as measured at the F317-1 harness 
connection of the PDB. Normally all voltages are stable.

I also tried moving the DB9 from the lower connection to the top 
connection, and all LEDs flashed at the 19.2 rate in sync. I thought 
that this might give us some useful info.

Item 2.

Tested the timing @ the D301-4 modules with the Tester and no indication 
of timing present.

Replaced the L305 and retested timing,  is now present and the D301-4 
modules report timing ticks.

D301 & D303 functioning correctly.
D302 middle channel low suspect tight or dirty connection @ the ant mux 
and/or D302 front panel.
D304 channel 3 low suspect tight and/or dirty connection @ the Ant Mux 
and/or D304 front panel.

Measured at the demux in control building all channels @ ~ -6.5 except 
the 2 channels where @ ~ -8 using the OSA.

The D30X remaining issues will be fixed 3/10. I had to give up the 
Antenna so John could perform some work he has been waiting to do.

Thanks,

Mike Le Blanc

-------------- next part --------------
A non-text attachment was scrubbed...
Name: mleblanc.vcf
Type: text/x-vcard
Size: 218 bytes
Desc: not available
URL: <http://listmgr.nrao.edu/pipermail/evlatests/attachments/20070309/14aa7dba/attachment.vcf>