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

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

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




If it tunes up in lock, all the relays are functioning (arguably)
properly. You didn't say if the issue was transmission in CW, SSB, or
both modes? That might direct things just a bit more. If the PTT
function works OK, then I'd check the audio ckts up to the balanced
modulator and the anti-VOX ckt. In CW, one needs to have the a key
plugged in and in use. In SSB, its just the PTT ckt (and audio input)to
bring it up.

de K3HVG

It may be as simple as a bad mike.

73, Colin K7FM

"Lee K. Gleason" wrote in message
. ..
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




Try swapping out V1 the first audio amp as half is used for the mike audio
and the other side is the tone oscillator. It is possible to to have rf out
on tune up, but nothing on ssb.

Leanne W1WXS

Leanne wrote:
"Lee K. Gleason" wrote in message
. ..
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




Try swapping out V1 the first audio amp as half is used for the mike
audio and the other side is the tone oscillator. It is possible to to
have rf out on tune up, but nothing on ssb.

Also, there are a couple of low voltage electrolytics in the microphone
stage that are always bad after this much time.

-Chuck

"Lee K. Gleason" wrote in message
. ..
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.


Thanks all for the answers & suggestions. Two problems were found. One was
that the microphone had a broken wire in the cable. The other problem was
between the ears - this is the first SSB transceiver I've had (tells ya how
long I've been inactive), and I was expecting power to show on the output
meters just from keyng the mike (you know, from the carrier, which is
nonexistent). Transmits fine now.
--
Lee K. Gleason N5ZMR
Control-G Consultants

On Feb 15, 5:58 pm, "Lee K. Gleason" wrote:
long I've been inactive), and I was expecting power to show on the output
meters just from keyng the mike (you know, from the carrier, which is
nonexistent). Transmits fine now.

The magic word to make it work correctly is "oooooola" repeated over
and over until you begin to hear foul language from the speaker. This
is best done on the air on top of an existing QSO
Then you know everything is working.

....this is the first SSB transceiver I've had (tells ya how
long I've been inactive)....

I guess so, since I was using a KWM-2A in 'nam in the sixties... 8

-- Larry

"pltrgyst" wrote in message
...
....this is the first SSB transceiver I've had (tells ya how
long I've been inactive)....

I guess so, since I was using a KWM-2A in 'nam in the sixties... 8

-- Larry

Well, my previous transmitter, last time I was on HF, was a BC-610...it
was designed well before SSB was even thought of.
--
Lee K. Gleason N5ZMR
Control-G Consultants