I measured mine at 110 mA relay current drain, which seems a little high to me. I threw in an extra 38 mA relay to key all that just to be safe, even though the Icom 7000 and 705 are rated for 200 mA keying current. My KX2 has no specified rating for amp keying, so it will be safer there.No, you don't need a relay buffer. Just get an RCA cable, cut one end off and wire the center pin and ground on the RCA cable to the correct pins on the radio interface. Simple!