From the schematic there should not be an issue unless the K3/K3s mic bias can't provide enough current for the preamp board. 73, ... Joe, W4TV On 2022-06-09 12:03 AM, Dave (NK7Z) wrote: > Hi, > > Has anyone here wired an Icom SM-2 to a K3 and had luck with this? Any > surprises in this?