cullen K5HAL wrote:
Looking for information on Dow-Key DKC-TR tube type TR switch. I have
one without documentation. I found the box it came in, no
instructions.


Hi

I also have a DKC-TR, with no instructions.
It should be usable on 160 thru 10 meters.

The two SO-239 connectors that have continuity thru the center pins
are for antenna and TX connections (doesn't matter which is which).
The other SO-239 (at narrow end) goes to the RX.

The cable has a black lead to 6.3V, a red lead to approx 125 to 150 VDC,
and a shield to ground.

The tube used is a 6AH6 pentode.

You should include a low pass TVI filter between the TR switch
and your antenna.

The BAMA mirror site has instructions for the DowKey model TRM
TR switch, which includes general TR switch usage guidance,
but is a different design, using a dual triode tube type 12AZ7.
Keep the cable length between the TX and the TR switch as short
as possible, to avoid "suck out" effects on RX sensitivity.

Also, the TR switch should be used with a class C final, or one
which has cutoff bias applied to the finals during key-up, to avoid
increased white noise in the rcvr.

73,
Ed Knobloch