Let me state up front that I am not an RF engineer, but I do have a EE background.
I'm working with a group that has a collection of radios, VHF and UHF (military) that is licensed to use a VHF and UHF frequency for over the air testing. They have also created a lab with a run of coaxial cable with taps at intervals connected to inline RF attenuators to which they connect these radios for isolated testing or for using alternate frequencies. They are typically using the same frequency (at a low power setting) and usually take turns transmitting (although this is not guaranteed). It seems to work, often quite well; however, it strikes me as potentially problematic. While these radios are naturally capable of voice communications, the bulk of their use involves digital data. I have observed situations where it is difficult to reliably exchange data and I struggle with the suspicion that it could be due to this connection configuration. So I'm seeking some opinions/guidance from those who probably far better versed that I.
First, is this even a legitimate thing to do? Second, is there a best way to do it?
I admit I know probably just enough to be dangerous, but my concerns when all of these transmitters are basically just connected to and operated over the same piece of wire:
- Cable run length/tap spacing
I sometimes feel like when this does work, it's really by accident and when it doesn't it just confirms my suspicion that it is a dodgy implementation.