[Andrew2]

Thanks for the fascinating info, Mistica. I've only just scrapped a Hatfield ten-way rotary antenna selector switch, which I bought second-hand at a rally about 30 years ago. Built like the proverbial concrete wash-house, it had eleven BNC sockets around its periphery and a shaft in the middle for rotating the switch. Good & sturdy, it was painted in the familiar hammer-finish blue.
What impressed me was the way all unselected ports were automatically terminated with a small, sprung carbon slug to stop any undue coupling or reflections on the other lines. I scrapped it when, after a couple of years of rather intermittent operation (and several clean-ups of the contacts), it finally gave up the ghost. It got a lot of use over those 30 years, as it was at the heart of my radio listening post with its many antennas.
I'm sure no-one makes anything quite like it these days.