A very small correction to Stargazers description.

What stargazer refers to as sub-frequencies, are not on a different frequency. The system uses a technique variously called, sub-audible tones, Private Line, or half a dozen other names. What happens is the radio transmits a low frequency audio tone at the same time it transmits the voice. The low frequency tone is filtered out and not heard by the operator. The radio is capable of transmitting many sub-audible tones and if the system is employed, it will only open the squelch on the receiver when the transmitted sub-audible tone is the same as the tone set on the receiver. For example. Suppose 4 radios are using FRS channel 1. With no sub-audible tones employed, all 4 radios will hear all conversations on that channel. Now if radios 1 & 2 employ a sub-audible tone say, tone #1, then radios 1 & 2 will only hear each other. But radios 3 & 4 will hear everything on the channel. If radios 3 & 4 now employ sub-audible tone #12, they will hear each other, but not radios 1 & 2.

Notice that they are all still on channel 1. Channel 1 can accommodate only one conversation at a time, so if radios 1 & 2 are talking, radios 3 & 4 will not hear them and if they begin transmitting they will interfere with radios 1 & 2, and garbage will result.

Techno-babble aside, the point is that when you are employing sub-audible tones, the frequency may be in use even though you do not hear anything. Most sub-audible equipped radios have a monitor button, which when pressed, temporarily opens the sub-audible tone squelch so you can listen for other conversations before transmitting. Listen before you transmit.

Also, you can hear a weak station better if you turn your sub-audible tone off. This has more to do with how the sub-audible tone system works than any change in receiver sensitivity.

More techno-babble. I have been playing with these (gmrs, & frs) radios for a long time. The newer walkie-talkies that work on both services, GMRS & FRS, usually transmit on GMRS at the lower power level specified for FRS. Even on GMRS only frequencies. I have checked several different brands and so far they all transmit at ½ watt OR LESS. Just because you are using a GMRS frequency, do not assume you will have better range.

We travel a lot and spend much time in remote areas. More and more we are seeing signs posted saying that the local “rangers” monitor FRS Ch#1.

If you have no other communications device, or are operating in an area with poor cell phone coverage I strongly suggest you and all members of your party carry FRS or GMRS radios. They are cheap and they work. Consider it a very loud whistle.

For those that have little experience with radio use, I will put together a suggested operating technique guide and post it in this thread for comment.