[Collins] PROBLEM SOLVED:THANKS FOR HELP EVERYONE RE: KWM-2 RECEIVE AUDIO DISTORTION

Sat, 22 Nov 2003 13:52:32 -0800

Team

Thanks to all for your many helpful suggestions. In accordance with your =
recommendations I replaced C-102 and C-101, readjusted receiver gain to =
Collins specifications and I installed change 36B (C227, 0.01uF added =
across C 106C) and the audio distortion on receive with strong signals =
has been completely eliminated!!!

As far as I can tell with on the air reports my KWM-2 is now operating =
flawlessly and the receive audio is *outstanding* even with extremely =
strong signals. The KWM-2 receive audio is now the same as (or better =
than) the receive audio from my ICOM IC-775DSP in side by side =
comparisons and the receive S meter readings are within 3 db of each =
other from S2 through S9 + 30 db....

Again, thank you very much everyone.

73, Ted, K6XN

ps I am now going to begin restoration of my 51S-1 :-).

-----Original Message-----
From: [email protected]
[mailto:[email protected]]On Behalf Of Park, Ted
Sent: Tuesday, November 11, 2003 12:54 AM
To: [email protected]
Subject: [Collins] NEED HELP RE KWM-2 RECEIVE AUDIO DISTORTION ON STRONG
SIGNALS

Team

I am restoring a winged emblem  KWM-2 serial number 15613 and I have, =
among other things, checked and replaced tubes, cleaned switch and relay =
contacts,  replaced all the electrolytic capacitors in the KWM-2 and all =
the electrolytic capacitors in the 516F-2 power supply. It now works =
perfectly except for one thing.....in receive on strong signals above S9 =
the audio becomes distorted. On signals less than S9 the receive audio =
is outstanding. If I reduce the RF gain on distorted signals the =
distortion disappears. I have tried replacing V15 and V16 with no change =
and all voltages and resistances measure nominal at the tube sockets in =
accordance with the KWM-2 manual. Other than the receive audio =
distortion on strong signals the KWM-2 now performs perfectly. Audio =
reports on transmit using my Collins SM-2 microphone with the KWM-2 are =
uniformly outstanding (Collins quality). Any suggestions regarding how I =
might solve my receive audio distortion problem would be appreciated. =
Thanks, Ted, K6XN