Types of Radios
Where to start with radio depends on a variety of circumstances. Are you a club and wanting everyone to be on the same channel? Are you a solo traveler looking for a radio that offers you the best chance of talking yourself out of a problem? Or, is it just you and a buddy looking for a cheap and easy way to talk from a few car lengths away up a trail?
Generally speaking, the vast majority of drivers have at least a passing familiarity with CB radio. CBs can be bought at most large retailers, truck stops, and online. CB radios tend to be very basic in design and rarely overly complex. There is no need at all for a license, although they are covered by rules set forth by the Federal Communications Commission (FCC). Because of the widespread use of CBs, you can normally find many people within a local off road community that have them installed in their vehicles. Most CB’s will need to be wired into your electrical system somehow and be fitted with an external antenna. The range is rather limited and often times simply going around a mountain bend with a convoy of 15 off roaders will be enough to limit lead to rear communications. Voice transmissions are either Amplitude Modulation (AM) or Single Side Band (SSB). AM power is limited to 4 watts and SSB is 12.
Amateur (ham) Radio
An Amateur Radio type of radio typically affords the most flexibility in terms of range and options. This is one of two that will be discussed that also needs a FCC granted license and the only one that you are required to take a test in order to transmit on. But don’t fret! The most basic license, called Technician Class, is generally regarded as very easy to pass and simply discusses basic theory and operation rules. Ham radio comes in a bewildering variety that spans from the lowest of frequencies (think AM broad cast band) all the way up to the giga hertz range. Axles and Antennas will primarily discuss the more popular 2 meter (VHF) and 70cm (UHF) bands. You will have a large selection of both vehicle mounted and hand held radios. The primary mode of voice transmissions is crystal clear Frequency Modulation (FM). Most handheld radios have a maximum power of 5 watts while many of the mobile units are have an ability to transmit at a scorching 50 to 100 watts! Range is measured in miles even when using a handheld radio as long as you have even the smallest of external magnet mount antenna.
Multi-Use Radio Service (MURS) is probably the least known of the types of radios that Axles and Antennas will cover. While somewhat obscure, it certainly has it’s merits. Usage of the MURS radio band is license free (technically license by rule) by the FCC and is normally, but not exclusive to, businesses. MURS is a VHF band and is actually just a few megahertz above the 2 meter ham radio band from 151 MHz to 154 MHz. Users are limited to 5 defined channels and power is limited to 2 watts. Radios are mostly handheld walkie-talkie type. These radios are allowed to have external antennas which will allow the user to attach an antenna to the outside of their vehicle to greatly enhance coverage. Voice transmissions are typically FM only by design of the radio. Unfortunately, MURS specific radios can be somewhat of a challenge to find.
General Mobile Radio Service (GMRS) and Family Radio Service (FRS) is a bit of a mixed bag of goods that will receive more clarification but here are the nuts and bolts. These radios are extremely popular due to their ability to be purchased in many department stores. Usage, however, is very misunderstood and often operated outside the legality of the FCC, mostly by accident. Both GMRS and FRS operate in the UHF portion of the radio spectrum between 462 and 467 megahertz. Purchased in a “bubble pack” GMRS/FRS radios kind of share a set of frequencies that have some overlap in available power, transmission type and channel allotment. FRS has 22 assigned channels while GMRS has 30. GMRS requires a test free license for all users over the age of 18 and FRS is license free. Depending on which band and which channel, available power is limited to 0.5, 2, or 50 watts. FRS is not permitted to have a removable antenna which limits your selection to hand held units. GMRS radios give the user a fairly good option of hand held and full mobile units. Again, these particular radios will be covered in fuller detail.
Axles and Antennas needs to cover this particular VHF radio very briefly and very clearly. Transmitting on a Marine band VHF radio on land is ILLEGAL under nearly all circumstances unless it an emergency that will result in loss of life or property. Not your cooler getting stolen but you are about to die. The FCC may have a hard time keeping up with all the little rule violations that come along with CBs, FRS, and ham radio, but the US Coast Guard monitors this band. They have very little sympathy for users who violate this. Just don’t do it.