The T/R relay contacts can be somewhat problematic. They get ugly, and
you won't get the proper signals and voltages to the transmitter.

First, take a piece of 3x5 card stock, about 1/4 inch wide, and dip it in
99% isopropyl alcohol. Slide the card stock between each contact multiple
times. The card stock should come out dirty, and it should not feel like it
is going to tear. Do this first with the contacts in the Normally Open condition,
and then activate the armature with your finger, and do the contacts that are
Normally Closed.

If any of the contacts are rough, and tear at the card stock, they will need to
be burnished (NEVER FILE OR SAND RELAY CONTACTS!). To make a simple burnisher,
you need a grinder, and a piece of hardened sheet steel, an old hacksaw blade will
do nicely. Grind the blade until it is 1/4 inch wide, and about as thick as the
card stock. The final grind should be perpendicular to the length of the blade.
The fine grinding marks in the steel do the burnishing. Put the tool between the
contacts, and apply light pressure while moving the burnish tool in a file like
manner. You are trying to maintain a crown on the contacts, so rock the tool,
in various directions, to keep that crown (convex) shape.

If the contacts are too horrible to fix, you will have to replace the relay, which
is quite a task if it is one of the wired in relays. The plugged in relays are a
standard relay, with the exception of the 10,000 ohm relay coil. They are available from
Surplus Sales of Nebraska most of the time. Or, you can buy a new 24V relay, and
steal swap its contacts into the old relay frame.

There are 3 relays, two under the chassis, and one in the HV cage.

-Chuck Harris

Lee K. Gleason wrote:
Just got around to trying to put a KWM-2A I bought a few years back on the
air. It's in roughish condition, but seems complete and usable. After
replacing a failed diode in the power supply, it recieves fine.

I've been trying to transmit, and there seems to be a problem. It tunes up
OK into my dummy load - the power meters in the dummy load indicate RF is
flowing while it's in the LOCK mode. When I try to transmit using the PTT
microphone that came with it, the relays clack when I key it, but...no RF
out. I'm wondering if this is a common problem - anyone heard of it?
--
Lee K. Gleason N5ZMR
Control-G Consultants