2 Kenwood TS590SG tranceivers can be connected together and one can function as subreceiver. This is very useful when using a separate RX antenna.

Firmware 1.04 minimum required. See manual page 60 - 61 of the TRX to see how to connect two of them.

Used part of this schematics DL1IAO SO2R Box only the audio part of it to switch the audio. Created a proto board to switch the two relays using 3 buttons selecting: Left TRX both ears| left ear left TRX, right ear right TRX(diversity)| right TRX both ears.

When it proved itself during CQWW 160m contest 2024 and know if I will use it more often, i will put it in a nice case with some proper cabling.