Here's how it's laid out with the group I volunteer with. All radios in use are VHF radios, most often MTS2000 Motorolla's since they are cheap, work well, and are basically the equivalent of the invincible Nokia phone. Communications are segregated across multiple frequencies. ALL rail Ops are obviously done exclusively on the singular frequency registered to the railroad that we operate on and none else. The next group of communications is the car hosts on the train. They are allotted 1 of 4 MURS frequencies that we have available and can do whatever they need to handle passengers or anything else without compromising rail operations. The third group is the station master/crew and ticketing desk. They are allotted the 2nd of the 4 MURS frequencies and can again freely do anything they need without worry. The remaining 2 MURS frequencies are not specifically allotted but are occasionally used for any miscellaneous communication that would interrupt or not belong on any of the 3 primary frequencies.

Any communication that occasionally needs to happen between the frequencies can usually be handled face to face since you are typically in close proximity to another member on the other frequency you need to reach. The Station Master who coordinates boarding with the Lead Car Host often chooses to carry two radios in order to cross-over. Though the Station Master and Lead Car Host are almost always located on either end of the boarding ramp anyways and can easily talk face to face without needing a second radio if they so choose. And last but not least, most of the radios are programmed to have all 5 frequencies available and you can easily switch to whatever frequency you need as necessary. This also allows us to effectively have only one set of radios without having to worry about coordinating and maintaining multiple sets or types of radios.

And something that's a little unique to our operation, we also have to use radio communication to interact with our local public transit dispatch and to use a remote switch to get to our station spur. We have to talk with the local transit dispatch because our line diamonds across the city light rail and bus system. We do this by number coding a tone on our rail frequency which causes a computer to alert the transit dispatcher who then verbally responds on our frequency, separate from their own frequency. When they give us verbal clearance for our move, we can then tone into the interlock computer which puts us into its traffic queue. Once it senses that we are safe for our move, it engages the crossing systems, aligns the derails on either side of the transit lines, and gives us a lunar signal to proceed. We also have to tone in to use the remote switch that aligns us to either our station spur or the "mainline". This is a remote switch because our station spur is a dead-end that also acts as the "derail"/protection for the transit lines on the museum side of the crossing since it is conveniently located where an actual derail otherwise would have been placed. It makes operations pretty convenient though because we never have to put someone on the ground to throw the switch to get in and out of the station every single run.

That's the gist of how we do it, though don't quote me on it because I'm not the expert on it. Sorry for the length, tried not to make you guys read an entire essay here. All together though, the system works VERY well, is simpler than it sounds, and the volunteers like it. Communications are smooth, clear and it has kept everyone safe and passengers happy!

And a note on ear pieces, several of us have tried using them before but had varied results in general. It is especially unpleasant when the computer system tones back with a very loud beep acknowledging the interchange codes or remote switch requests. No one has continued to use an earpiece to my knowledge. Corded mics/speakers on the shoulder has been the default for everyone and it works very well.

These radios were on the cars in 1949?? Where did they put a bunch of vacuum tubes on those 'Louis cars?

By then they could make radios pretty small relatively speaking by then. They could get to the size of a hefty lunch box.