QSK amplifier keying circuit for Kenwood Radios (TS-950/850/450/870/570/2000)
On the TS-950/850/450 radios the amplifier keying relay can be turned off and the REMOTE connector 12v line (pin 7) is still active for keying the amplifier. With TS-870S Menu Item 51 (the amplifier keying relay) must be "ON".
This circuit has been tested with Alpha 87A, 89, 99, 91B, 8100 amps. An assembled cable is available from Alpha/Power for $69.00 (plus S&H).
NOTE: This circuit does NOT work with TS-940, TS-930, TS-440, TS-430 radios. They do not have 12v available on the REMOTE connector. Use the amplifier keying relay connections as described in the Kenwood manual (pins 4 and 2).