[Collins] Need Advice - KWM 2A Transmitter Problems

Fri, 11 Jul 2003 08:39:07 -0400

Paul, start by checking all of the set's tubes. Next, check the power supply
DC voltages, and be sure that the filament voltages are correct as well.
Then clean all the switches and controls. Then do an alignment. That will
help you zero-in on the errant stage/s. I used to repair them in the US Army
(they were designated RT-718s).

Vy 73, AI2Q, Alex in Kennebunk, Maine
http://users.adelphia.net/~alexmm/ai2q.htm

 .-.-.

---Original Message-----
From: [email protected]
[mailto:[email protected]]On Behalf Of John Page
Sent: Thursday, July 10, 2003 11:07 PM
To: [email protected]; [email protected]
Subject: Re: [Collins] Need Advice - KWM 2A Transmitter Problems

There are many things that could cause this. But the easiest and cheapest to
do first is to CLEAN the bandswitch. Might as well clean the rest of them
while you are in there. Now try it and tell us how it did. John

John Page K4KWM
Hollow State since 1953
(ex W8PKU,N8BLB,NA8O)

>From: [email protected]
>To: [email protected]
>Subject: [Collins] Need Advice - KWM 2A Transmitter Problems
>Date: Thu, 10 Jul 2003 21:16:30 -0500
>
>I recently purchased a WE KWM 2A (circa 1968) that appears to have
>transmitter
>problems on some bands.  It appears to be working somewhat on 75 and 40
>meters but the other bands won't load up at all.  It makes no difference
>if I tune
>it up into a Laboratory 50 Ohm dummy load or into an antenna, the
>behavior is
>the same.
>
>Here are my observations:
>
>75 & 40 Meters
>
>Tunes up and loads OK with slightly lower plate current and RF output
>than the
>book values in the manual.  RX seems to be OK.
>
>20 Meters
>
>No grid current indication in tune position.  RX noise peaks but no plate
>current
>thus unable to dip plate or measure any RF output.
>
>15 Meters
>
>Grid current & exciter peak very touchy.  Was finally able to get tuned
>similar to
>75 & 40 Meter behavior.
>
>10 Meters
>
>Same characteristics as 20 Meters unable to get it to load up
>
>Prehaps those of  you with specific Collins experience, especially
>"hollow state"
>knowledge of this rig can give me some ideas of where and what to look at
>to
>get this repaired.  I'd also appreciate any insight into who might
>specialize in
>KWM 2A repair & alignment.  I'll be anxiously awaiting your replies .....
>
>Paul - K8PD
>Noblesville, IN
>
>
>