I know how to program the system. Alternate CC's are not used as voice channels.Unless something was just changed, there are 5 there. Keep in mind that the Alternate CC is a voice channel when the Primary CC is working. CSP does not rotate CC but some systems do. You want to have all the CC programmed in so a channel failure will not prevent you from monitoring. If you aren't sure, program in all the sites frequencies.
I stand corrected.Sorry, you got some bad information somewhere. They most certainly are used as voice channels.
Usually they are programmed to be the last to get traffic but they do get used. Here is the traffic breakdown for Troop H, Prime Site 9 for the last couple years. Keep in mind that the 6th channel was only put in this past summer.
853.2625 - 0 - PCC
852.7625 - 178 hits - ACC
852.4125 - 376276 hits
851.9375 - 376511 hits
851.4000 - 3383 hits
851.0375 - 380208 hits
The 3 channels that have so many hits are the primary channels for this site. So while 178 hits in 6 months is minimal usage, it is in the rotation.