I climbed up to the roof of the ATC tower and noticed the nice antenna mount. Really! Except maybe for the part with the open end of pipe where the wires come out and the rain goes in. And the way the UHF radio antenna is mounted upside-down. It's not like the radio waves will care, but water can accumulate in the radiator this way.

About this time I notice the white cable used for the GPS antenna looks a lot like the white cable for the UHF antenna. A closer look shows it is (they are) 75-ohm cable. But I have a 50-ohm UHF antenna. This is going to look less than wonderful when it comes time to check VSWR.

The good news is that the guys got in the habit of disconnecting the antenna cable from the UHF radio when they left. Lightning protection. But they forgot to hook it up one day. The system worked fine. We are so close to the met tower we don't need an antenna. Wow.