[Collins] VOX hang up fixed

[David Knepper]

The fix for the VOX relay staying keyed was to replace the those two- 2watt
68K resistors, R9, R112 on cathode pin 8 of V11A, the VOX Relay Actuator.

Note that in the later 32S3A, those resistors were changed to one-5watt 34K,
which no doubt Collins engineers knew was a better choice rather than two-
68K 2 watt resistors in parallel because they recognized the high failure
rate of those 2 watt resistors - even they were 4 watts total -  in the
earlier circuit which goes back to the 32S-1, I might add.  These two
parallel resistors are used in the KWM-2's so if the same problem occurs,
change out those resistors.

Replacing the resistors with 2 brand new 68K's in parallel solved the
problem.  The original resistors exhibited resistance well above the 34 K
needed in the circuit.  Looking at the color bands should have been a good
clue since the colors were rather faded from all the heat that the resistors
have to generate.

So if the relay closes prematurely, check R9 and  R112 or better yet, just
change them out.

These two resistors have been widely documented in the literature as
potential problems in the VOX circuit.
No wonder Collins went to a 5 watter.

Dave, W3ST
Secretary to the Collins Radio Association
Publisher of the Collins Journal
www.collinsra.com