MURS/FRS/GMRS RADIO: the new "CB Bands"This is where GMRS sits today, and licensed GMRS users need to wake up to reality when whining about unlicensed operators. Radio is (and has always been) a use-it-or-lose-it world. GMRS has enjoyed its private little heyday, but the writing is on the wall, thanks to deregulation and cheap electronics. The FCC opened up portions of the band, which gets little use in most areas, to allow some licensed/unlicensed frequency use. Manufacturers jumped on the bandwagon, turning out thousands of FRS/GMRS units that allow unlicensed operation on some channels, and licensed operation on others. Can the radio tell if you have a license? No, it will let you use ANY channel. At some point the FCC will realize the error of its ways (if, indeed, it didn't intend to give the band away on purpose), realize there are far too many GMRS radios being used without licenses for them to prosecute, and change the rules so its not an issue anyway. So the only question you need to ask yourself is, are you operating that unlicensed combo FRS/GMRS radio where it will piss someone off (like a licensed operator). Even with the high power models, your range is limited. Live in an urban area? You may want to purchase a license for C.Y.A. purposes. Using your radio for talking with your hunting buddy in the mountains? For you, a GMRS license is money in the garbage. Yes, the risk is always there, of getting busted and made an example of. People get hit by lightning, too - but nobody seems to mind walking around outside - what matters is the odds.
Each type of system has advantages and disadvantages that can work for, or against you. Example: for the extreme sport of 4x4 offroading, CB radios are generally considered to be the weapon of choice. But they are not necessarily the best option (my 4x4 is equipped with CB, FRS, and FRS/GMRS units). For instance, when the club I explore with goes on safari, we use FRS radios more often than anything else. Why? Well they usually have enough range for the group to keep in touch on the trail, they are the same size as a CB microphone in your hand (without the coiled cord to try to avoid tangling with), and they are dirt cheap - which means I can carry extras for extra drivers who join in, and it doesn't bother anyone terribly if one gets dropped in the mud, driven over, or left in somebody's glove box 2 states away.
- A) In a boat on the water
- B) In an aircraft
- C) Went to some extraordinary effort to get the range
- or D) are bragging/lying to cover the fact that they got burned, too.
Manufacturers list the range as the maximum possible, under ideal LABORATORY conditions. This means that for you to match their claims, there can be absolutely nothing between radio A and radio B, the batteries must be perfectly charged, the air must be perfectly free of moisture/dust, antennas have to be held at a matching angle, etc. Not to mention perfectly quiet listening conditions at the other end. None of which happens in the normal world of radio. By trying to match these conditions, you can make a big difference in range, to be sure. A good example is a Motorola Talkabout FRS that I bought listed with a "2 mile range". Normal use around a housing neighborhood would only give me a couple of blocks range, despite the "2 mile range" claim. However, with my wife standing on the roof of our house, and me talking from the 3rd floor window of my workplace 2.5 miles away, at night (clearer air), we were able to hear each other (barely). Why the difference? The VHF and especially the UHF band used by FRS and GMRS is a 'line of sight' band. You need to be able to "see" the radio you are talking to for a good signal. Anything in the way will block some or all of the signal - buildings, trees, hills, even dust. The lower the frequency (as in CB radio), the less line of sight is needed, as it is not as bothered by objects in the way.
- Base Station: These units have the advantage of operating from house current, and usually have provisions for external, desk-sitting microphones, external antennas that offer increased range, and lots of quality enhancing features like tone controls, noise reduction filters, etc. Most ideal for operating from a home or place of business, or where the longest range caspability is desired.
- Mobile: This type of radio is designed for vehicular use, whether in a car, truck, boat, or airplane, almost always powered by 12VDC from the vehicle battery (in some cases 24VDC). Has a separate, handheld microphone, and many features also found on Base Stations, including matching transmitter power output. However, because the mobile antennas for these units have size and mounting height limitations, they rarely get the same range as a base station. Mobiles also feature amplified speaker output to allow easy listening even in a noisy vehicle.
- Hand Held or "Walkie-Talkie": Most convenient form of radio, also the most limited, as it usually has to rely on the features that make it so conveniently portable, such as internal batteries, small cases, and small antennas. Batteries run down quickly, quickly cutting range long before they are dead. Small cases cut down available features and speaker size (volume). And of course, the small built in antenna (practically non-existent in some models) cuts your range drastically from what a true mobile or base station antenna would offer.
If you are looking for economy and don't mind some sacrifices, a full featured hand-held unit can probably cover every use you might have. "Ham" radio operators have written the book on this idea, buying inexpensive hand held radios for "carry around" use, then hooking them to voltage adapters, antenna adapters, and RF amplifiers for use as a mobile and/or base station radio. In this manner one radio can work in the place of 3, saving some money. The trade-off is that you lose some "user friendliness" having to constantly plug and unplug connections (which also cuts radio 'life' due to wear and tear), and the smaller hand held radios often scrimp on RF power and audio output, which reduces range and signal quality over a mobile or base station. But if you want a cheap start, or versatility, this is the way to go.
On the other end of the stick, if you are looking to eek out the last iota of performance, then a system of tailored radios with a full complement of antennas and other accessories is the way to go, although this will mean a premium outlay of funds as well.
Most likely, you'll be after something in between. In any case, the key thing is to carefully consider (FIRST) what you want your radios to DO, then buy what will cover that. The woods are filled with hunters carrying "2 mile range" FRS walkie-talkies that sit unused in camp because they don't transmit thru more than a hundred yards of trees.
AUDIO QUALITY
INPUT: Whether you are talking about MURS, FRS, FRS/GMRS, or a true GMRS unit, your radio's microphone is where your signal is created. Aside from talking clearly (which so many people on radio seem to have problems doing, out of various 'bad' radio habits), the quality and type of your microphone can make all the difference in the world in how you are heard on the other end of the conversation. Even radios that traditionally come with good quality microphones, such as GMRS radios, can often benefit by an upgrade here, such as using noise-cancelling microphones in high noise areas.
OUTPUT: Base and Mobile style radios rarely need help in this department, usually having adio amplifiers and larger speakers built in to overcome all but very high noise environments. Handheld Walkie-talkies are another matter altogether. Audio volume and quality from these radios are usually dismal at best, and renders them useless in any kind of noisy location. Fortunately, there are answers to this problem, as most handhelds come with an earphone jack. Those same, inexpensive, amplified speakers sold for iPods or computers work well here, or in a mobile environment you can use a patch cord or FM transmitter to play your walkie takie audio over your car stereo. And of course, riding the noisy ATV doesn't stop the comms if you have a combination earphone/microphone headset.
ANTENNAS: It cannot be stressed enough that this is the cheapest, yet most significant improvement you can make to your radio, regardless of style, band, output, whatever. And often the biggest range improvements can be made on the cheapest radios for a small amount of money and effort. When properly constructed and installed, a bigger, better antenna will do amazing things to your reception and transmitting range. The location of your antenna is also very important, too, often affecting range more than anything else. This is why a 1 watt GMRS base station with a full sized antenna mounted on a tower will often have a range of several times farther than a 5 watt GMRS radio with a 2 inch antenna transmitting inside a car. Keep in mind, however, that the same reasons the better antenna is an improvement (larger physical size and height above terrain) also may mean it can't be used in some circumstances - for instance, it sort of ruins the point of carrying around a pocket-sized walkie-talkie if it is hooked to a 3 foot high antenna, regardless of the range improvement. Conversely, hooking that same walkie-talkie to the same antenna on the roof of a house or vehicle makes great sense for the increase in range, since the radio doesn't need portability in those cases.
POWER AMPLIFICATION: Here, it is usually owners of low powered radios that have the most interest. Users of true GMRS radios can have repeaters and external amplifiers similar to those used by Ham Radio Operators, sometimes giving hundreds of miles in range. MURS users could feasibly use VHF band amplifiers as well, although this would violate FCC regulations covering MURS radio and you would risk a heavy fine in most cases. Owners of FRS and FRS/GMRS hybrids are those who most often ask about boosting the output of their radios - often remembering how easy it was to do this with many CB radios. But times have changed, Sparky! Read on if you dare:
RANGE/POWER OUTPUTThere are some important things to consider before upgrading your antenna, because doing things wrong can actually decrease your range.
Your antenna should be properly tuned to the frequency you are using. Think of your antenna as the lightbulb in a flashlight. Using the right style bulb means the flashlight will work correctly, and a brighter bulb will shine the beam farther. using the wrong style or voltage bulb means it will be too dim, burn out, or just plain not work. The same is true for antennas, sometimes even for the same reasons. Unlike receiving antennas (like the coat hanger hooked to car radio in the trailer park) which usually don't have to be tuned, a transmitter antenna will reflect some of the transmitter power back into the radio unless properly tuned. This will at the least affect your range, and with high powered radios can even damage the transmitter! So it is important to have a good quality, tuned antenna. For many radios these easily found but can be pricey for the better quality ones. For some radios (like the FRS units) thse are virtually non-existent. All is not lost however, with a small amount to electronics ability, you can build one!
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A SPECIAL NOTE ABOUT POWER MODIFICATIONS: Due to a large volume of email concerning power upgrades on FRS walkie talkies, I include some basic, common sense tips here to address the issue. The reason many want to upgrade the power level of their H/T's is pretty obvious -- better range. Since most GMRS equipment costs several times the price of a FRS unit, and requires a license as well, doing a quickie upgrade on the ol' H/T looks attractive. Unfortunately, this is far from the truth. Why? First, and foremost, it's illegal. The way FCC rules cover the subject, using or being in possession of (which is considered by FCC regs as the same thing) such a device makes you subject to fines of several thousand dollars and up to 2 years in jail. Rules in other countries such as the UK and Canada are even more strict. However, many may be counting on the low odds of the overworked government monitors catching them. More on this in a moment. That said, let's address the technical issues. First, lets make sure you have the tools you need. Many old CB'ers may be itching to do a quick tweak of the finals using a RF meter and a tuning tool - won't work here guys. Unlike CB's, FRS radios operate with FM instead of AM modulation. So by increasing your microphone modulation or adjusting your power stages improperly, you get a phenomenon known as frequency splatter. Instead of boosting your power doing these adjustments (as on a CB), you only cause your radio to transmit in a wider, unstable frequency band. This can actually degrade your power levels. So as a minimum, you need a good frequency counter, a precise audio generator, and a frequency deviation meter, in addition to the normal tools you'd use to tweak a CB. Major $$$ for all that. Next, check the circuit board - most likely you won't be able to get your hands on a service schematic, and most of the parts will be Surface Mount Device (SMD) types and sealed against vibration (and hence, adjustment). So chances are that even if a radio technician bequeaths his repair shack to you in his will, you can't use it anyway. Strike Two! Finally, and assuming you've gotten past the first two hurdles, let's talk about component replacement. Most of the FRS breed of radio have output stages that are driven nearly to max levels. This means any "tweaking" will only give an increase that you might see on a meter, but can't measure in range - which is pointless (see the final note at the bottom of this section). So you'll have to replace the final amplifier transistor and associated components. If such parts even exist, which they may not, you'll need manufacturer's service documents and specs on the new parts. How can you tell if these parts exist? Well there is actually a pretty common sense guide that can tell you if any radio is "upgradable".
In summary, if you want more power, buy it. Cheap upgrades don't exist, and unless you own your own shop and know how to use it, you're playing with fire, anyway. If you insist on working higher power on the FRS channels (since GMRS radios won't operate on all of them), a GMRS amplifier designed for mobile or repeater use could feasibly be driven by some FRS radios. Another option would be re-tuning a Ham amplifier designed for 70cm band (440 Mhz). A final note on boosting your H/T: just about every model of FRS radio suffers from the same demon: Short battery life when transmitting. Assuming you could boost the power output - even a mild range increase would gobble batteries like a kid with Christmas candy. Notice the power ratings on High vs. Low power UHF H/T's: you must quadruple the power output to get double the range (if that). this is why the higher power units use a 9-12V battery pack, instead of the standard 3-4 AA/AAA batteries that FRS H/T's use. |
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NOTES
2.Many hybrid FRS/GMRS radios number the frequencies according to how they are stacked in the radio's programming (usually in order of frequency, not channel number). Because of this, GMRS frequencies may appear incorrectly numbered on the radio's channel readout (radio may indicate channel 10 when really transmitting on GMRS Simplex 6, for instance). If you intend to use a hybrid to communicate with true GMRS eqquipment, consult your owner's manual for information on what frequencies are actually being used for each channel.
