[Elecraft] K3 with xmit and receive antennas - advice needed

[Ken Kopp]

John,

The "switched 12V out" you're referring to is switched 
on with the K3's POWER and remains in an ON state 
as long as the radio is on.

There is a "keyed to ground" connection (KEY OUT)
that -might- meet your needs to switch an external
relay, but I don't know it's current / voltage limitations.

Doesn't ANT 1 and ANT 2 meet your needs?  They are
selectable with the ANT button on the front panel.

Maybe I've not understood your question .....

73! Ken Kopp- K0PP
     ElecraftCovers at rfwave.net