Pardon me for questioning your advice, I have tried to read everything I can on here to learn first without asking for too much help, but what I have read indicates that the system uses all the frequencies and switches around... otherwise why list them in the group if they do not need to be programmed in? I thought the control frequencies were the ones with the data instructions, and the actual vice transmissions are carried on the remInder of the frequencies. How will the radio follow those frequencies if I only have the control freqs programmed in? Do I have the system misunderstood?
Again, thank you for your assistance, this has been very frustrating trying to learn and figure it out.
Here is a simple explanation of how Motorola trunking works.
MOTOROLA TRUNKING
The object of trunking is to allow many users to share a relatively few frequencies.
A trunking system is controlled by a computer. Information (data) is exchanged between the system radios and the computer on a control channel, sometimes called a data channel. It sounds like a strong buzz.
A large system can have up to 28 freqs., 4 of which may be used as control channels. The control channel may be changed once a day or as often as the programmer decides. Some scanners need only the control channels to track an entire system. Just put in all the Control Channels.
Each group of users (Fire, Police, etc.) is assigned TALK GROUPS. In a Motorola Type II system, the most common type, TGs are usually in 32 number steps starting with 16 and going up to 65536; 16, 48, 80 --- 4656, 4688, 4720 --- 28944, 28976, etc. System radios can have more than 100 TGs programmed into them.
Digital systems are similar, but the talk groups use every number (like 2491, 2492, 2493, etc.).
When a user pushes the talk button on his radio, data is sent to the computer. The computer chooses an unused freq. and sends that data to all the radios using the TG of the originating unit. This all happens in a fraction of a second and it happens EVERY TIME a radio is used.
EXAMPLE:
Fire Dispatch calling Engine 4 (TG 4528 on 856.7125)
Engine 4 answering Dispatch (TG 4528 on 852.2625)
Respond to 73 Elm Street (TG 4528 on 855.9625)
Engine 4 responding (TG 4528 on 851.6375)
If you have entered TG 4528 into your scanner, it will decode the control channel data and change your scanner freqs. to follow the conversation on TG 4528.
ALSO: After you enter the control channels, press SCAN. Then it will start to "trunk".