Two-Way Radios

                                                            ***Disclaimer*** 

This is the opinion of the writer and should not be considered an endorsement by Kokopelli ATV Club. 

2-way radio basics...

We are all familiar with receive-only AM & FM radio, allowing us to receive music, talk shows, & news reports.  In addition, TV (over the air, satellite or cable) allow one-way communications to receive those radio signals. In order to communicate at a distance, two-way radios are needed that will transmit and receive.

Just so you are aware:  Per the FCC (federal communications commission), any emergency can be transmitted on any frequency without a license, provided it truly is an emergency and you follow basic communications rules. Also, a license is NOT required for two-way communications on CB, FRS, MURS & Marine bands. (band descriptions are below)

We've heard about CB radios used mainly by truckers, but off-road enthusiasts advocate using CB, FRS, MURS, GMRS, Marine, PLM, and ARS bands for radio communications.

• GMRS requires filling out a form and paying $70 for a license which lasts 10 years. 
• Marine bands (specific ones) are free to the public, but we're not close to an ocean.
• PLM is typically reserved for business use of specific frequencies.
• ARS requires you to pass a test and pay a license fee before using ARS frequencies. 

You can carry a portable two-way radio (like Baofeng) or mount a 'base station' (like PCI or Rugged Radio) on your Side-by-Side so that you can transmit and receive. A portable radio can be somewhat shielded from direct sunlight, heat and dust when placed under garments and close to you, otherwise you need a radio (mounted in your rig) that will survive harsh environments. 

Two-way radios have a limited distance (less than 50 miles) depending upon the power levels (listed in watts),  type/structure of the antenna, tuning of the radio/antenna, and the type of terrain where you are riding. The distance to receive radio transmissions could be less than 1 mile.

Some radios can also receive FM radio (88-108mhz) and/or emergency weather stations (162mhz) which is a nice plus. Some Jeep off-road clubs use CB radios (27mhz), but it would be very difficult & very rare for any radio to cover both CB and FRS/ARS/GMRS/PLM frequencies.  If you purchase a two-way radio, try to get one that operates on both 140->170mhz (PLM) and 460->470mhz (FRS/GMRS) frequencies.   

Kokopelli ATV Club has used GMRS/FRS, PLM and amateur radio bands for communication. 

It's common on rides to be transmitting on 153.110mhz (PLM), rather than FRS, GMRS, or MURS.

Our use appears questionable, but it is a frequency used by other clubs, off-road racers and individuals, so we assume it is acceptable. 

Personal Radio Services | Federal Communications Commission (fcc.gov)
General Mobile Radio Service (GMRS) | Federal Communications Commission (fcc.gov)

The acronyms can be confusing, so here is some reference for radio use.
Over the air communications is referred to as RF (radio frequencies), which operates at a 

multitude of frequencies expressed in hertz (a term used to describe cycles-per-second). 

• khz [kilo or thousands of hertz]
• mhz [millions of hertz]
• ghz [giga or billions of hertz])

Two-Way Communications:
 CBRS  (citizen band radio service)  30-channels, max 4-watt at 27mhz
 FRS  (family radio service)  22-channels, .5-watt & 2-watt max  (recently allowed for business)
 GMRS  (general mobile radio service)  22-channels (7 are FRS only power levels), 

           max 2->50 watt, 462mhz and 467mhz (8-additional GRMS channels used by repeaters)
MURS  (multi use radio service)  5-channels, max 2-watt, 151->154mhz 

           ( 151.820mhz, 151.880mhz, 151.940mhz, 154.570mhz or 154.600mhz )

  PLM  (public land mobile) 150->174mhz & 421-512mhz, 18->100 watt, typically industrial use

  LMR  (land mobile radio) PLMRS (private land mobile radio service) --> same as PLM
 BRS  (business radio service)  multiple frequencies used around 30, 40, 155, 465mhz
 ARS  (Amateur Radio Service)  multiple frequencies used at:

          ( 54mhz, 144->148, 222->225, 420->450, 902-928mhz )

One-Way communications: 

  LPRS  (low power radio service)  one way communications for people with disabilities

          (transmit only, can't receive)

TV,  AM radio,  FM radio,  Cable TV,  Satellite TV