About Two-Way Radio Frequencies

There are three distinct kinds of two-way radio communications called the base station, vehicle-mounted and hand-held portable walkie-talkies. Other two-way radio devices include outdoor and indoor call boxes. Brokers, traders and media officials need to communicate on a “line-of-site” within and around their business infrastructure while maintaining the secrecy of their communications.

Types of Two-Way Radio

The most common two-way radio communications are portable hand-held walkie-talkies. These gadgets are frequently used by employees of security firms or military personnel. The operating frequencies and their ranges are governed by Federal Communications Commission (FCC). Most walkie-talkies are rated to operate about five watts of power outputs. They are about twice the size of a mobile phone with an antenna on top and a microphone and speaker inside. Two knobs control volume and frequency-band. The latest walkie-talkies have LCD screen plus extra buttons.

Mobile Two-Way Radio Transmission

Mobile Outside Broadcast Vans used by the media have vehicle-mounted two-way radios. During signal transmission from the van, the radios use the van’s DC power source while base stations located at repeater stations use AC power through step-down capacitors. The FCC allows mobile vans and base stations to operate at a much higher power output of up to 100 watts compared to the hand-held variety.

Two-Way Radio Frequency operation

The operating frequencies are mostly dependent on type of service. Very High Frequency (VHF) range (30-300MHZ) and Ultra High Frequency (UHF) range (300-3GHZ) are available for commercial communications. To enable communication both radios have to be set to the same frequency band. UHF is mostly reserved for commercial communications while VHF is largely used by licensed General Mobile Radio Service (GMRS) and unlicensed Family Radio Services (FRS).