Two Way Radios

Here, we will cover some very basic things about two way radio types, operation frequencies and range.

1. Two Way Radio Types

Two way radios usually come in three distinct types: portable, vehicle-mounted, and desktop base station. There are also unique two way radio devices such as indoor and outdoor call boxes and one-way radio receivers for wireless paging.

Handheld portable two-way radios are the walkie talkie type of radios you see people carrying around. As ruled by the FCC (Federal Communications Commission), handheld two way radios may not have more than 5 watts of power. They usually look like a rectangular box, with a large antenna sticking out from the top. They have a speaker and a microphone, and some control knobs. These knobs are usually 2, one is used for selecting the channel frequency and one is used for setting the speaker volume and turning the radio on and off. Most devices nowdays also have some kind of LCD screen for displaying information and additional buttons for menu navigation.

Vehicle-mounted mobile two-way radios mount in a car or truck and they use the vehicle’s battery for power. Desktop base station radios use wall AC power and are allowed to transmit at much higher power than handheld devices. Transmit powers of as much as 100 Watts are not uncommon.

2. Two Way Radio Frequencies

Operation frequencies largely depend on the service, with both VHF (30 – 300 MHz) an UHF (300 – 3000 MHz) two way radios being available. Check out the VHF vs UHF Two Way Radios article for a comparison between those two frequency bands. The UHF two way radio band is reserved for business two way radios, while the VHF band is widely used both in non-licensed (Family Radio Service – FRS) and licensed (General Mobile Radio Service – GMRS) public systems.

3. Range

The range of a two way radio can be anything from a few hundred meters up to an advertised few tens of miles, depending on the frequency used, the wattage and the conditions. More specifically, UHF radios have better range inside buildings than VHF radios, but VHF radios have a longer range in line-of-sight transmission. Increased wattage leads to increased range but also decreased battery life. Weather conditions, such as increased humidity or thunderstorms, can reduce the range. Always bear in mind that manufacturers’ claims concerning range are always a bit exaggerated, since they assume optimal conditions (i.e. line of sight transmission, clear weather etc) which are always never present.

4. Digital Two Way Radios

Some two way radio systems use digital links and they can transfer data as well as voice. Typical data rates are between 1.200 and 19.200 kbit/s. Virtually anything can be sent or received, but the most usual type of service is text messaging.