Trunked system control channels

[85chevy4x4]

Ok so it's my understanding that when programming tower sites for a trunked radio system that the only nessicary frequencies are the control channels, and that the control channel will tell my scanner(Pro-106) which frequency to tune to, although its not actually on the list of frequencies programmed for that system correct? I see that on the list for the Ohio MARCS system there are a few other frequencies listed for each tower, but there not marked as primary or alternate control channels, therefore not nessicary to program correct?


Ohio MARCS - Multi-Agency Radio Communications Trunking System, Statewide, Multi-State - Scanner Frequencies Ohio MARCS Radio System

 

[SCPD]

You pretty much got it right...the only caveat is that there can be missing control channels! In other words, a system could conceivably use any frequency licensed to the system as a control channel and/or the RR database may not have a freq marked as a primary or alternate control channel on the system. There are a few systems in my area where this was the case. Easy to tell though.... If you suddenly are no longer tracking the system, check for this possibility.