The local trunked UHF radio system causing interference wanted to talk about more than just interference–they have a problem with radios randomly failing to transmit. I told them I would monitor their transmissions and jot down if I hear anything
Monitoring for LTR trunked radio system overloading
In a modern digital trunking radio system, all sorts of statistics are available. For an LTR system, most controllers are not that sophisticated. What will happen in LTR is that if too many groups are homed on one repeater, the chance of two people keying up before the repeater can make its first response goes up. Then, either neither party can transmit if the overlap is early (no clear-to-talk), or both will transmit. In the first case, out-of-range tone is given. In the second case, clear to talk is given but the transmissions are uselessly garbled (or maybe, one signal dominates).
Solving LTR trunked radio system overloading
It involves reprogramming every radio in the system, so get your plan in order first. You should distribute home channels for different groups that talk at the same time. If your system needs an “all call”, you probably have a small dispatch console that can key multiple radios simultaneously–if not, you’ll need to implement one.
This solution is fairly unique to LTR. As digital trunked systems come online in response to the 2013 narrowbanding, this problem will slowly and naturally go away as LTR systems are sunsetted.