Frequency/Trunk List Legend


I usually format my frequency lists the same way. The format I use is demonstrated below with an explanation of how to read it.

179.9 153.860/158.955 *CITY of Pearland EMS Dispatch (STAR-Net trunk 13808)

The first number is the PL or DPL tone used (if any). If the number has a decimal point, it is the PL (CTCSS) frequency in Hz.

If it is just three digits, it is the DPL (some call DCS) code.

The next number (in this case 153.860), is the (repeater) output frequency in MHz. This is what you would typically program into a scanner to receive the base and mobiles.

Since it has a second frequency after the "/", this indicates that it is a repeater system as opposed to simplex.

The frequency after the "/" (158.955) is the repeater input frequency in MHz. This is what the mobiles actually transmit on when using a repeater but you would be better off listening on the repeater output frequency to hear everybody.

There are a few exceptions to this whereas someone may operate "half-duplex". Many taxi companies and some Texas DPS channels operate where the base is on one frequency and the mobiles are on another but the mobiles are not repeated through the frequency used by the bases.

The next field indicates the service, agency, and sometimes other information.

In this case, it shows that the city of Pearland EMS operates on the STAR-Net trunked system and uses talkgroup 13808. The audio from the talkgroup can also be heard on 153.860 MHz.

Sometimes, a channel number may be indicated. On some aviation frequencies, the UHF (of VHF) counterpart may be listed.

In many of my lists, I use certain letters and terminology whose meaning may not be that obvious.

In this file, I hope to explain the meaning of these so that the information they provide will be more useful.


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