I'm with Jim, I have a Koss SB/45 that plugs directly into the rear of the K3. I get great audio reports and it's only $25 on Amazon. Ken WA8JXM On 9/5/15 2:00 AM, Jim Brown wrote: > Can't help you with that part of it. I use Yamaha CM500, which plugs > into the rear panel connecters. Far superior and MUCH cheaper.