CT programming
emt_531, you do not "need" to program the tones, but I find it helps properly identify what I am receiving - especially with CAL FIRE. I am not sure where in California you are, or what you monitor, so I am not able to provide an exact example. But for me, using a PRO-97, I have the following programmed:
x00 151.4000 110.9 CAL FIRE OROVILLE
x01 151.4000 103.5 CAL FIRE MARIPOSA
x02 151.4000 search CAL FIRE TAC 10
x10 151.4600 136.5 CAL FIRE SANTA ROSA
x11 151.4600 123.0 CAL FIRE MARIPOSA
x12 151.4600 search CAL FIRE TAC 12
In my examples the order of programming is important; in that the "search" mode (no tone) is programmed last. I program a frequency several times (in these examples 3) and program specific CT values. If no CT is received, it must be a TAC channel.
This is just one example of using CT programming. There are many other applications.