Most hams are aware of, and might use, a duplexer or triplexer on their VHF and UHF radios. Being able to share a multiband antenna with multple radios of different bands is certainly a plus when you have limited real estate on a vehicle or even at home. But did you know that duplexers and triplexers (really, multiplexers) are available for HF antennas as well?
I suspect most hams have their multiband HF radios tied to one or more HF antennas and probably not the other way around. But what if you wanted to attach multiple radios to the same antenna? Steve, KB9PVH, alerted me to this fact and, after a bit of research, I found VA6AM’s HF multiplexers (I believe the ones Steve uses are made by a different company).
So, now I know how to share my HF antenna, by why would I want to do such a thing? For my use-case, I want to have multiple HF radios attached to my BBS (via Netrom) so I can support multiple bands simultaneously (including cross-band connections). Some contest or DXpeditions could use these if antenna space is at a premium and they wanted to put multiple radios on the air at the same time. I’m sure there are other use-cases for such a device.
So, the next time you wish you could use that one really good HF antenna you have for multiple radios, now you can.