Range of FRS/GMRS radios and an intro to MURS
The range of FRS/GMRS radios is wildly over-rated. You shouldn’t believe the advertising claims. They are OK as a cheap radio, within their limitations. If you are going to go with this band I recommend instead the Garmin Rhino hand-held GPS with GMRS radio built in.
Note- KE4SKY has the same regard for this radio as I and many other users in the loop also have found
These low-power UHF radios with fixed antenna are reliable within a half mile or so unit-to-unit in average terrain. To get longer range you must have an unobstructed line of sight path between units, no blocking buildings, foliage or terrain. They work great if one station is up high in the clear on a mountaintop talking to somebody down in the valley below, but if you are inside your car talking to somebody else in a convoy, do not depend upon hearing each other if you cannot actually SEE the other car.
Best is to get your ham license and a 2-meter rig. Portable ham rigs do much more than direct unit-to-unit simplex. Repeaters provide wide-area coverage, phone patch, and Voice Over Internet protocol over linked repeaters providing transcontinental and international coverage.
If you aren’t interested in studying and taking the exam for a ham license, the best bang for the buck for local communication within a few miles, is the Multi-Use-Radio Service or MURS. The Business Pool VHF frequencies formerly known as the VHF “color dot” frequencies were moved from Part 90 to Part 95 of the FCC Regulations to became a new Citizens Band Radio Service for private, two-way, short-distance voice or data communications service for personal or business activities of the general public.
No license is needed. Anyone in the US is authorized by rule to operate a MURS transmitter if they are not a foreign government or a representative of a foreign government; they use the transmitter in accordance with the rules. No illegal activity, no profanity, be an adult and play nice. An MURS station is not required to transmit a station identification announcement. The channels authorized are available on a shared basis only and may not assigned for exclusive use of any entity. Users must cooperate in the selection and use of channels in order to reduce interference and avoid interference to other MURS transmissions. Around cities you will hear fast food drive-in windows, warehouse operations, trash collection, building maintenance and construction site crews. The wide-band FM channels 154.57 and 154.60 get more use than the 151 Mhz. narrow-band ones.
MURS operation is authorized anywhere a CB station is authorized.
MURS operation is NOT authorized aboard aircraft in flight.
Unlike FRS and GMRS, MURS stations may transmit voice or data signals, including digital selective calling or tone-operated squelch tones to establish or continue voice communications, remote control and telemetering functions, except that MURS transmitters may not be operated in the continuous carrier transmit (CW or morse code) mode.
MURS users shall take reasonable precautions to avoid causing harmful interference. This includes monitoring the transmitting frequency for communications in progress and such other measures as may be necessary to minimize the potential for causing interference. This all comes under the general heading of that the FCC calls “good operating practice.” It is common sense and courtesy. MURS stations are prohibited from operating as a repeater station or as a signal booster. This prohibition includes store-and-forward packet operation. MURS stations are prohibited from interconnection with the public switched telephone network.
The biggest advantage of MURS over FRS is that you can use a more efficient, elevated antenna with “gain” to increase your useful “radio horizon” and range. http://www.dpdproductions.com/page_murs.html At VHF frequencies antenna height is more important than transmitter power. The higher the antenna the better the reception. For two hand-held units on flat terrain, standing in the open without foliage, buildings or terrain obstructions, with both transceivers held at face level, theoretical line of sight is 5 miles, which is the best range you can hope for on simplex without improved antennas.
If the transmitting station remains standing with the transceiver held at face level, but the receiving antenna is elevated 25 feet above ground, range approximately doubles to 11 miles. If the receiving station were standing on top of a 250 foot hill the line of sight range would be about 20 miles. The highest point of any MURS antenna is not allowed to be more than 60 feet above the ground or 20 feet above the highest point of the structure on which it is mounted. Using a 6dB gain vertical antenna, at maximum legal height, fed with low loss coax such as LMR400 on your home base, and having a 3dB gain 5/8 wave mobile antenna mounted on the roof of your vehicle, having a good ground plane, you can work mobile-to-base simplex from 10-20 miles, depending upon terrain.
The frequencies available in the Multi-Use Radio Service are:
Frequencies Authorized Bandwidth
151.820 MHz 11.25 KHz
151.880 MHz 11.25 KHz
151.940 MHz 11.25 KHz
154.570 MHz 20.0 KHz
154.600 MHz 20.0 KHz
Multi-Use Radio Service transmitters must be certificated in accordance with Part 95, Subpart J of the Commission’s rules. Business band land-mobile radio service radio units certificated prior to November 12, 2002 do not be re-certificated. You can buy used, surplus VHF “high-band” business radios and have a commercial 2-way radio shop program them for you into the MURS frequencies and legally use them without a license.
No MURS unit, under any condition of modulation, may exceed 2 Watts transmitter power output. This is not the handicap it may seem, because unlike FRS, there are no antenna restrictions. While it is illegal to use a A VHF marine band radio on land, http://www.mcminnarc.com/marine.html antennas which are designed for the VHF Marine band will also work just fine for MURS. A 3 dB gain 5/8 wave antenna whip on your vehicle doubles effective radiated power.http://www.dpdproductions.com/page_murs.html#mursmobile58ngp
On your cabin erect a 6 dB gain base station vertical antenna on the chimney cap or above the highest point on the structure.
http://www.palmettoantennas.com/vhf-base-station-antenna-ham-2-meter-murs-fir2.html This quadruples effective radiated power. A higher gain directional yagi antenna, http://www.bluestarantennas.com/home/product_info.php?products_id=185 having at least three, but ideally four elements or more on a boom of at least half wavelength (about 1 meter) gives the longest range in fixed location point-to-point operation. An antenna of 10dB gain, resonant on your working frequency could reliably communicate up to 50 miles or so with a similarly equipped station up on high terrain and in the clear.
An easily found option for MURS and 2m here
This is a 7Dbi gain antenna which is an improvement as decibel increases are geometric.
A reliable source for refurbished business band radios is http://www.reddogradios.com/index.php?dispatch=categories.view&category_id=213
They can provide business band ICOM VHF portables reprogrammed for the 5 MURS channels for a little over $100 each. If you also have a ham license they can also program your local ham 2 meter repeaters and simplex frequencies into the same radio.
Thanks to KE4SKY for another informative post