Hi Tom, I have ran two HF rigs twice. The first time I was using a Kenwood TS 520 and a Ten-Tec Omne D and Now I still have the Ten-Tec and I also have a Kenwood 2000. Both times I used a good coax switch backwards from the rigs and the common went to the antennas. I only have one now but before I ran the common to the common of a five position switch. They were farther apart before because I had more room but now I would say there is 20 inches between the two rigs. I hope this helps. 73 Walt and GEB dog Opus WA4QXT New London CT mailto: [log in to unmask]