Greetings, I have a TS-830s and am looking for a VFO unit for it. Do I need (want) to have a VFO-820 or will any Kenwood VFO unit work? Is there anything that's is compatible and better? Will any other units like a Yaesu 101DM work? Thanks in advance. C.L. Sutton KI4BUN / AAV4TP/T