Some emergency scanners are able to use trunk scanning technology. Trunk scanning allows you to not only listen to normal emergency broadcasts, but to also listen in to special channels that are opened during large-scale events to allow emergency personnel to communicate with each other. By programming trunked frequencies into your emergency scanner, you can stay informed about major events, even potential disaster, in your community.
Enter programming mode on your scanner by pressing "Prgm" on the control panel. Press the "Trunk" button to select the trunked frequency option and then enter in the trunk number you want to program. This will be a number between 1 and 10.
Locate a list of available trunk types and frequencies. One way to find the frequencies for your area is to use a map such as one available at Radio Reference. Write down both the trunk type and the frequency for each agency that you wish to monitor in your area as you will need both.
Press the "Up" and "Down" buttons to select a type of trunk frequency that you want to save. These types are determined by the type of broadcasting equipment that is used to operate on these frequencies. Each one has different emergency signals on them.
Press the "E" or "OK" button and the scanner will tune in to the first available frequency on the trunk you selected. Use the number pad to enter in the first frequency you want to save on this trunk type, including the decimal point.
Press the "E" or "OK" button to save the frequency. To program another frequency in this trunk, press the "Prog" button and repeat the process using a different trunk type and frequency.