Well, RF over fibre is a bit mangled, as of course we can send audio and video on fibre but not rf, that is electromagnetic in nature so carrier free, but it doesn’t go down fibre.
the problem with comms is the use people have in mind. Remember that for many people, comms is something they use but don’t understand. In practice it’s far more complex, and also depends where you are. Clearcom is worldwide, but historically since the 90s in the U.K. it was less common, by a big degree because we had Canford Audio’s Tecpro system. This would need to be in U.K. rental inventory if your customers do theatre. However, over the past few years, it’s taken a decline in popularity and I now see Clearcom far more than I used to, and new builds and revamps are moving to Clearcom, or a Clearcom compatible systems. We’re really talking about ring systems here. The ones where you have the comms line carrying one or two channels of analogue audio that belt packs and desk style units get plugged onto. A ring. You take a line from an output and slap in into a new pack, and it just works. Everyone hears everything and typically you can split it. For entertainment you might have the DSM on channel 1 while the follow posts can talk to each other on channel 2, but they’ll also be listening to channel 1 for cues. Clearcom spec or Trantec spec are NOT the same, the levels and line impedance are different. Plugging them together often produces weird effects, instability and even feedback. The system works by having an audio line at relatively low impedance and then having outstations of a higher impedance bridging the line. As long as there are not too many, it works fine. Clearcom used to describe it as party line, as in everyone can hear and talk to everyone.
the alternative, becoming more common now is point to point systems. Everyone has a choice of who they are linked to. A ’star’ system where there is a programmable hub, and the idea being that. People are put into groups, so somebody decides who hears and talks to whom. This was common in television but is spreading. Especially as now it can be digital over a network it’s pretty easy to arrange. The party line being described as 2-wire and point to point has two way audio, described as 4-wire in analogue.
RF systems are frankly terrible. When they work, they’re great, but often they’re awful. I’ve just done ten weeks where I only realised how awful they were when I borrowed one half way through to cover somebody. Broken audio, constant “out of range” messages when I was normally using an analogue, old fashioned system over a far greater distance. These were Clearcom and everyone using them hated them, but they had no cables.
RF is a difficult subject to describe quickly. It is not concrete that is a problem, but the rebar inside the concrete. It works like a Faraday cage, and signal strength through it is greatly reduced and even worse it is frequency dependant. The holes in your microwave cooker’s door let light through but stop 900W of very damaging RF cooking the user. UHF radio might get through some rebar, VHF struggles. In my case I’ve got some 5GHz video kit and it got through quite a few concrete walls. I had assumed it would not, but was very surprised it did, when 800MHz struggled.
for hire inventory, you will need to find out what your customers already have. Here, I have been a Tecpro user for years, and really like them, but while a Tecpro pack sort of works sometimes, it’s not reliable and can make the system unstable, so not just a make up some cables solution. Now Clearcom do different systems within the brand it’s even harder to hire. Buy what your customers are using. I‘ve even got a few point to point systems for specific purposes. U.K. theatres seem to be refitting with Clearcom, which is a shame.