The General Mobile Radio Service, the Family Radio Service, and the relatively new 900 MHz handies that have come on the scene, are all capable radios that can have the same purpose: personal or business short range communication. VHF Marine radios are different. More on VHF Marine later.
The least expensive of these three personal short-range radios are the Family Radio Service (FRS) handies. The FRS radios are limited to 500 mW output or half a watt. Realistically they are good for anywhere up to 1 mile depending on terrain. The FRS handies are license free, which is a big advantage. These handies have 14 channels available. CTCSS tone encoding could lessen interference in large urban areas, but they still only have 14 channels. The CTCSS does not add channels.
FRS was introduced by the FCC in 1996 as an inexpensive and license free mode of communication for personal and business use. Interestingly, the only way you can now get a new FRS radio is to buy new old stock (NOS), as no manufacturer builds an FRS-only radio anymore. Any new radio sold for this service is a combination of GMRS and FRS.
The General Mobile Radio Service (GMRS) handies are more expensive. They have a higher output, typically 1 to 4 watts, although some top-of-the-line GMRS handies have so-called power boost options which brings them up to 5 watts output. That's about the limit that you can get out of the handie battery. In case you think 5 watts isn't much output, think again! The vast majority of Amateur (ham) radio Handies also have a maximum output of 5 watts. Anything more than this, and the batteries will drain very rapidly during transmit! The GMRS handies do have a further range but don't believe the hype about 20, 28, 34 miles and so on. In reality you'll get about 10% of that. So you are doing well if your GMRS handy reaches 3 to 4 miles. Of course, if you're on a mountaintop or out on the lake on a boat, you'll get further range because there are no obstructions.
GMRS was introduced in the 1960s by the FCC. At that time they called it the class a citizen's radio service.
GMRS has a total of 22 channels. However, FRS and GMRS share 7 UHF channels, so your handie will automatically switch to low power (500 Mw) when you transmit on certain channels. Like FRS, GMRS handies are also available with CTCSS tone encoding.
The GMRS handies require a license from the FCC, which ain't cheap at $85. However, you will be in contravention of federal laws if you operate a GMRS radio without a license.
The 900 MHz handies, which are relatively new on the market, use one watt output and are license free. They operate with a technology called frequency hopping spread spectrum. This technology is similar to cell phones but remember these handies do not use cell phone repeaters. The range of these handies would be comparable to a GMRS radio with 1 to 2 watt output.
Marine VHF is strictly for marine use! If you don't have a boat, don't use these radios. The FCC has (and will again) fine people for unauthorized use. Just do a short search on the net and you'll see! There's plenty of information on the FCC website about rules and regulations pertaining to VHF Marine frequencies... they (and the Coast Guard) take unauthorized use of these frequencies very seriously. Very recently, Cobra has introduced a handie-talkie with both GMRS and Marine VHF frequencies. These may make a great addition to your boating activities.
