[Kenwood] Various previous posts on keying older amps with newer low voltage rigs.

[Bill]

Here is an article on keying an older amp.
http://www.eham.net/articles/22194

W2ENY makes a relay for Icom and I believe he has one for Kenwood as well/

http://www.ab4oj.com/icom/auxrelay/main.html

This also from Adam some time ago
Yaesu makes a neatly packaged auxiliary keying relay, the FRB-757, which
interfaces the low-current keying line of a modern transceiver to the
high-current keying relays of many tube-type amplifiers. The FRB-757 is
fitted with RCA-ended pigtails which  plug into the transceiver and the
amplifier; it requires an external 12V DC source. I believe that the
FRB-757 is still available from dealers, and costs approx. $30.

http://www.qsl.net/icom/auxrelay.html

I have more posts I've saved over the years. I think I have an FRB-7575 somewhere. I know I have the W2ENY relay and still have the home brew one buried. I was ready once...
Bill Marx W2CQ