The numbers 156.7 is actually a frequency; it is a subaudible tone of the frequency 156.7 Hz.pinellasfirefighter said:when is see a frequency to enter in and after the frequency there is 156.7 p.l. what is this?
This is true. I have done this and have heard the various CTCSS tones. A good set of headphones works, too.kb5udf said:PS on some radios, if you hook them up to a suitably large speaker, you will hear the PL tone as a humming in the background.