FAMILY RADIO SERVICE (FRS)
The Family Radio Service (FRS) is an unlicensed UHF service that the FCC has allocated for the good of the people. Since no license is required, anyone can obtain and operate FRS equipment at any time. All FRS radio are made as handhelds and battery operated. They operate on a total of 14 different “channels” as shown in the chart below. An additional chart also shows the allocated tones for privacy channel use.
The FRS channels are in the same frequency range as the General Mobile Radio System (GMRS) service which is often used by business interests such as construction. The GMRS radio are allowed much higher power levels (5 watts) and not only use some FRS frequencies but they have other frequencies close by. GMRS requires a license to use. The last I checked it was a 5 year fee of $80.00 for GMRS operation but it does cover all members of your family. That makes FRS look very attractive.
Many of the radios also have digital tone encoding to keep the receiver squelch closed unless that particular tone is received. That does not prevent interference from other users on that channel once the tone has been received and the radios squelch has been opened. What it does allow is a quiet receiver until the specific tone has been received on the channel being monitored. There are 51 different tones available but most manufacturers seem to talk about 38 Privacy Channels. The chart below lists the tones but I can't tell you which tones any given manufacturer uses. All tones are in Hertz.
| 67.0 | 69.3 | 71.9 | 74.4 | 77.0 |
| 79.7 | 82.5 | 85.4 | 88.5 | 91.5 |
| 94.8 | 97.4 | 100.0 | 103.5 | 107.2 |
| 110.9 | 114.8 | 118.8 | 123.0 | 127.3 |
| 131.8 | 136.5 | 141.3 | 146.2 | 151.4 |
| 156.7 | 159.8 | 162.2 | 165.5 | 167.9 |
| 171.3 | 173.8 | 177.3 | 179.9 | 183.5 |
| 186.2 | 189.9 | 192.8 | 196.6 | 199.5 |
| 203.5 | 206.5 | 210.7 | 218.1 | 225.7 |
| 229.1 | 233.6 | 241.8 | 250.3 | 254.1 |
The FRS channels, as well as the GMRS channels often have repeaters set up on them. A GMRS repeater can operate at powers levels up to 50 watts. This further complicates FRS use as it places high power transmitters, often on mountain tops overlooking areas where individuals wish to use their radio. Too partly offset this issue, the FRS radio seem to have been designed with very poor receivers. They just are not able to hear very far. I suspect that the receiver is the limiting factor in the published specification of a 2 mile range.
Family Radio Service radios are FM or frequency modulation radios. This means that as you talk the carrier frequency (as listed below for each of the 14 channels) is varied up and down coinciding with your speech. If nothing is said, the frequency sits still. As you talk it moves back and forth within a predetermined but narrow range. The receiver detector on the other end of the conversation then translates these frequency shifts back into audio that comes out the speaker.
GMRS & FRS Channel Designation Frequency
FRS Only Channel Designation Frequency
There are any number of manufacturers making FRS radios. Although you see many names, if truth be known, there are most likely only a handful of companies building them but with lots of different names. Names you will see include: