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FRS, GMRS, and Other LettersJune 13/09 Written by Greg Most of you have heard the acronyms "FRS" and GMRS" mentioned whenever the subject of trail communications comes up. And sometimes VHF, FM, frequencies, channels, and other equally-mysterious techno-mumbo-jumbo. But what does it all mean, and, more importantly, what are the bare essentials that YOU need to know to get by? Thankfully, there isn't a lot that you actually "need" to know. But there are a few things that you SHOULD know. Channels and FrequenciesA "frequency" is basically a slot in the RF spectrum that a radio is using to send or receive a signal. It has a numerical value, such as "462.5750 MHz". Since most of us find it inconvenient to memorize all of the numbers, and tell our friends to "tune your radio to 462.5750 MHz", the radio manufacturers have assigned "channel names" to each of the frequencies that our radios use. It's much easier to say "switch to channel 16". So, a 22-channel radio essentially has 22 radio frequencies that it can use, and rather than try to have non-technical end-users refer to the actual frequency numbers, we just refer to them as "channels". FRS and GMRS channels are shared-use; anyone can use them, and nobody owns them. Just like our shared-use trails. FRS/GMRS Radios No doubt you've seen the little hand-held radios labelled "FRS" or "FRS/GMRS", manufactured by numerous manufacturers who in turn have dozens of models with all sorts of features. This is the type of radio that most of us on Quads.ca use. The acronyms "FRS" and "GMRS" actually refer to two different "radio services", or intended uses.FRS stands for Family Radio Service, and it's intended for use by, wait for it, families. This means that practically anyone in a family can use it to talk with anyone else in their family, or their friend's families, etc. So you can reasonably expect to hear ALL SORTS of stuff on FRS channels, including little kids babbling back and forth, people in passenger vehicles travelling around town, parents calling kids home for dinner, and pretty much anything you can think of. GMRS stands for General Mobile Radio Service. In the USA there are restrictions on who can use the GMRS (ie. adults with GMRS radio licenses) and what sort of communications they may conduct, but in Canada we have no such restrictions. So in Canada, just like with FRS, you can expect to hear all sorts of communications. Some, but not all, of the GMRS frequencies are the same as the FRS frequencies. Speaking of radio licenses, in Canada the FRS and GMRS are license-exempt. We do not require radio licenses or operator licenses to use FRS or GMRS radios in Canada. In Canada, you will find the older FRS-only radios, and the newer hybrid FRS/GMRS radios. It would be extremely rare to find a GMRS-only radio in Canada. So What's the Difference?For the purposes of this article, the main difference between an FRS-only radio and an FRS/GMRS radio is the number of channels. An FRS-only radio has 14 channels. An FRS/GMRS radio has 22 channels. Some of the channels are shared by the two services. The other notable difference between an FRS-only radio and an FRS/GMRS radio is that the GMRS frequencies are "high-power" frequencies, meaning that as long as you are using a GMRS frequency, your radio can use a higher output power. This allows for better "range", or distance between radios. An FRS-only radio is limited to 0.5w RF output power. That's half a watt. An FRS/GMRS radio is limited to 0.5w on FRS frequencies, and 2w on GMRS frequencies (Americans are allowed 5w on GMRS frequencies). The actual power output on GMRS varies by radio; some are 1w, some are 2w. Read the specs to be sure. The GMRS shares some frequencies with the FRS. Manufacturers of hybrid FRS/GMRS radios automatically assume that you would always want to use the high-power GMRS and not the low-power FRS, so for the channels shared by the FRS and the GMRS, these channels are always high-power channels in an FRS/GMRS radio. So, in an FRS-only radio, channels 1-14 are all 0.5w. In an FRS/GMRS radio, channels 1-7 are high-power, channels 8-14 are low-power, and channels 15-22 are high-power. This is because the FRS low-power allocation is for the first 14 frequencies, and GMRS high-power allocation is for the first 7 and the last 8 frequencies. So you can see that our hybrid FRS/GMRS radios cover both the FRS channels and the GMRS channels, and where the services overlap, the radios assume you are using the GMRS and therefore use high power on the overlapping channels. To optimize communications range, always try to use a high-power channel. If you have an FRS/GMRS radio, but some of your group has FRS-only radios, use a channel from 1-7. You may not hear them if you get too separated, but they have a better chance of hearing you. Why always use a high-power channel when a low-power channel might do? Yes, if you use low power you can limit potential interference from your group to others, and save on battery life. However, when we're in the bush, the potential for us interfereing with others is minimal, and if somebody takes a wrong turn or needs to call for help, you don't want to attempt to get your group to switch over to a high-power channel when you're spread out along the trail. Range ClaimsIf you read the radio range claims on the retail packaging, you'll see all sorts of wishful distances like 12 kms, 30 kms, 40 kms, 35 MILES, etc. These are MAXIMUM figures. You MIGHT get that kind of range if your radio and the other radio are 40kms apart, at the top of mountain peaks, with no obstructions like rocks and trees between you. Basically, FRS/GMRS radios are line-of-sight radios, meaning the radios essentially have to see each other to be able to communicate with each other. In the forest, you might be limited to a couple of kilometers, no matter which "distance" your radio is supposed to have. With respect to radios, there are two important considerations that affect distance. The first is the RF output power of the radio. Read the specs, either on the packaging or in the User manual. The higher the output power, the better the range. A 2w radio will have better range than a 1w radio, all other things being equal. The other consideration is the antenna. Some antenna designs are better than others in certain terrain. This is why two radios from the same manufacturer might have the same output power but one claims a longer range. Outside of the radio, there are numerous factors which can affect your range. Interference from such sources as your stator, ignition, and EFI computer can decrease range by increasing your noise threshold. If a weak signal cannot overcome your noise threshold, you will not hear it. As previously mentioned, obstacles such as trees can partially block a signal. Climbing to a higher elevation (reducing obstacles) can increase your range. So what good are these range claims if they're essentially unattainable? Change the "distance" number to a "relative range indicator". Now that we're not dealing with actual distances, generally speaking the higher the "relative range indicator" the better the potential range. So if you are looking at two radios, and one has a relative range indicator of 30, and the other has a relative range indicator of 40, you can be reasonably sure that the "40" will have a better range than the "30". What Features Do I Need?If you're looking to buy a new radio, make sure it's a hybrid FRS/GMRS radio.  Get the highest-power radio you can afford (or the one with the highest "relative range indicator"). Note that higher-power usually means shorter battery life. Some radios come with a "range boost" button; this just means that the radio has two power settings, one standard setting and one higher-power setting when the button is pushed. This feature might increase your battery life, but you just have to remember to use the button when you're further away from the other radio.All current radios are equipped with sub-audible tones, aka "privacy codes", CTCSS tones, and other similar terms. These "tones" are not audible by most humans (hence the term sub-audible). If switched on, your radio sends a tone along with your voice. If your friend's radio has the same tone switched on, he will only hear transmissions from radios sending that tone. This means that the two of you can conduct a conversation in relative quiet, even if there is noise or distant users on the channel. However, ANYONE else can hear your conversation if they are not using a tone. The tone is ONLY designed to reduce interference heard by your group. If you are hearing interference, you can use a tone so that you don't have to listen to static or other people all day. The downside to using a tone is that if somebody outside of your group hears you talking and tries to call you without knowing what tone you are using, you will not hear them. As far as other features, nothing else really matters. Beep tones, voice scrambler, built-in flashlight, blah blah, who cares, as long as the radio portion works well. That means that you are understandable over the radio, and you can understand people talking to you. There are some considerations though. Not all radios are created equal. Some "sound" better than others. Some are built better than others. For consumer-grade radios, Motorola has some good quality units. High-end radios such as the ones made by Icom are very nice, but the cost puts them out of reach for most casual users. I always try to encourage people to buy one of the Garmin Rino units. The Rinos are a GPS with an FRS/GMRS radio built in. They have the additional feature of being able to send their position over the radio to other Rinos, and can poll other Rinos to find their positions. So you can see where all of your Rino-equipped friends are located, right on your GPS screen. At the very least, you will have a waterproof FRS/GMRS radio. How Do I Use It?First of all, always speak in plain English. This means, no CB trucker lingo, no 10-codes, etc. This is very important when you're trying to locate or give directions to a lost rider, or are requesting help from your first-aid person. Keep your transmissions short! Say what you need to say, and nothing more. This allows urgent and priority communications to get through, such as somebody calling for help because they just rolled their quad. Don't hold the PTT (push-to-talk) button down for long periods of time; if you're relaying information, break once in a while in the event somebody has higher-priority traffic. To transmit, press the PTT button, WAIT a half second, then speak in a NORMAL voice about an INCH from the microphone. Release the button when you are finished. It's important to wait for that half-second before speaking, as a lot of people cut off their first syllable or word because they're in too much of a hurry, and time is wasted when the other person asks you to repeat what you said. And if you holler into the microphone, you will sound distorted at the other end. Many people yell into the microphone because they think that's what they have to do to be heard over the sound of their engine, but it doesn't work that way. If you speak too close to the microphone, you will be distorted or muffled. If you speak too far from the microphone, you will be too quiet. So, when transmitting, try to remember "wait, inch, normal", or WIN. What About The Other Letters?You really don't have to know anything else to buy and use these radios. But just in case you were wondering, here's some additional info for you. The FRS and GMRS radios operate in the UHF spectrum. Essentially, they are pre-programmed UHF radios. UHF stands for ultra-high frequency. The majority of logging road and trucking frequencies are VHF. VHF stands for very high frequency. VHF and UHF radios are not compatible; they use different portions of the RF spectrum. This means that you are not going to find a radio that will work on both FRS/GMRS channels and logging road frequencies. Kind of like trying to hear an FM broadcast station on your television. FRS/GMRS, and VHF radios all operate in FM mode. FM stands for frequency modulation. FM is superior to AM (amplitude modulation), which is what Citizen's Band (CB) radios use. If you're interested in radio communications beyond what the license-exempt services provide, you might want to consider obtaining your Amateur Radio license. |
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