{Collins} 651S-1 progress - it's alive!



Thanks for all the suggestions and encouragement.
Tacking wires onto the A14 board and scoping showed that the 10's of MHz
counter was counting OK, just putting 00 onto the backplane. While checking
out if the problem was with the other boards connected to these two bits, I
discovered that those two lines were shorted together somewhere in the
multi-layer backplane. Luckily the short wasn't in buried lines, but a
teensy solder bridge hidden under a support bar and too small to see
without lots of magnification - who'd have thunk it!
Now I have a receiver that goes up to 29.9999 MHz instead of just 9.9999
And removing/inserting cards cleared up my LSB/ISB issue, so all that's
left is fixing the meter lamp.

An interesting discovery was that the DFCE card is labeled "PROPERTY OF
651S-1 ENGR. GRP." - I wonder what the story is on that......

Again, many thanks for the helpful replies to my request for advice.

Cheers,
Nick England K4NYW
www.navy-radio.com



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