I've been told that Telex can still re-band those systems to be legal, but why bother? Intercom doesn't need high fidelity or low latency, so newer systems are moving off into VHF (RAD), 1.9GHz (FreeSpeak), etc. to leave more UHF space for "legacy" UHF-R and PSM.
Agree with most of this BUT, latency in intercom, as well as how the side tone is derived can be of critical importance. If someone is giving a "Go" cue, or even more importantly a "STOP!" cue, latency can be a problem. An important thing to be aware of is that analog systems like BTR and Rad Com generate side-tone by making the full round trip from pack-to-base-station-to-pack virtually instantaneously, while IP based systems like Free Speak generate side-tone locally in the pack (because the latency would create an echo to the user). There are two critical issues with latter system: 1) when the person on the pack hears themselves say "Go" or "Stop" isn't, by some tens of milliseconds, when the rest of the PL hears it, and 2) there's no guarantee that the rest of the PL heard it anyway.
This is why choosing the type of wireless com to use can be very important when life safety is involved, say, for rigging and automation folks when a show involves flying people in-and-out or moving set pieces etc.
Full disclosure: I am the manufacturer's rep for Radio Active Designs in Canada.
