FAMILY RADIO SERVICE

TECHNICAL FAQ

TECHNICAL DETAILS ABOUT FRS

FRS radios can use a maximum of 1/2 Watt of transmit power on any of 14 frequencies. They operate around the 70cm band from 462.5625 MHz to 467.7125 MHz using Frequency Modulation [FM].

Maximum bandwidth is 12.5KHz with 25 KHz spacing.

Signal Scrambling is permitted on FRS - most commonly implemented through frequency inversion ala Cobra and Kenwood. The use of CTCSS is also permitted.

The specific frequencies for FRS are...

You may note that the first 7 FRS frequencies match up with the simplex frequencies for GMRS radio gear. .

WHAT'S THE STORY WITH CTCSS AND SUBCHANNELS?

The first thing to say is that these are NOT additional channels, and do NOT keep your conversations private.

CTCSS is essentially a way to keep your OWN radio from hearing transmissions you don't want. It does not keep anyone from listening to your transmissions.

It does not add additional channels. There are only 14 of them, each one can carry one transmission at a time [within the given transmission area] - no matter what CTCSS tone is used. If two people try to talk on any given channel at the same time in the same area, even if they have different CTCSS tones selected - they will interfere with each other.

CTCSS [Continuous Tone Controlled Squelch System] is a way to tell your radio not to open the squelch on incoming transmissions unless the transmission has a SUBAUDIBLE TONE [a tone that you can't hear but your radio can] that matches one your radio is set to use. If a transmission comes in without a matching tone, your radio won't open the squelch - so you won't hear it - even though it is still there.

When you set up CTCSS in your radio, you tell it what tone to listen for. The standard tones for most CTCSS-capable devices are listed below. FRS Radios use a sub-set of 38 of the total of 50 tones allocated for CTCSS and are listed in blue below...

If you are planning on using this feature, make sure that all of the radios in your group are set to the same tone.

We don't recommend using this feature for the following reasons....

• There can still be only one transmission on a given channel in a given area at the same time. If you have a CTCSS set in your radio and someone else has a different one - if you both try to talk at the same time you will interfere with each other.

• CTCSS is not secure. If I set NO CTCSS in my radio, I will hear every transmission on a given channel in a given area, even if they have CTCSS set in their radios.

• If someone is calling for help and they have NO tone set in their radio - you won't hear them if one is set in your radio.

FRS AND GMRS ARE NOT THE SAME

You may notice that the first seven FRS frequencies correspond to the simplex [talk and listen on the same frequency] frequencies allocated to the GMRS [General Mobile Radio Service]. GMRS radios require a license [money only, no tests] and run at higher power levels. This can be an advantage [users of both radio services can communicate] or a disadvange.

An FRS user might be able to hear a GMRS user who is some distance away because the GMRS radio is more powerful. The GMRS user may not hear the FRS user trying to talk to them because the FRS radio is limited to 1/2 Watt. This is one factor to keep in mind.

Please also be aware that some stores - including Radio Shack - unknowingly sell GMRS-type radios as if they were FRS radios. I have walked into a couple of Radio Shack stores where the sales person indicated that they had an even better FRS radio that put out 2 Watts for longer distances.

This was a GMRS-type radio, and you need to purchase a license to use these. The Radio Shack employee indicated that it was just like the "other" FRS radios until I pointed out the difference in their own catalog. They didn't know, and if you bought that GMRS radio to use like an FRS radio without paying for the GMRS license, you would be breaking the law.

If it is a true FRS radio, it won't output more than .5 Watts.

FRS OR CELLULAR PHONE? WHICH SHOULD I BUY?

This is actually an easy decision. When you want to communicate, is the other party customarily within 1.5 miles, and will they have an FRS radio?

If the answer is "Yes", then an FRS radio is the better choice. If you just want to talk to family members while you - and they - are at the mall or some other close distance, then a set of FRS radios will work fine.

If the answer is "No", or you want to have emergency communications while on the road - say to call AAA to fix a flat, then a cellular phone is the better buy. You can't count on FRS radios going further than about 1.5 miles, and you certainly can not rely on them to get you roadside assistance.

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