Which device is usually needed to extend the range of portable radios?

• A. A scanner
• B. A repeater system
• C. A duplexer
• D. A telemetry converter

Answer: (B)

Extending the range of portable radios relies on using a repeater system. A repeater sits at a higher location or with greater transmitting power and receives your signal on one frequency, then re-transmits it on another frequency at higher power, effectively expanding coverage for all radios operating in that area. Often, a duplexer is used within the repeater setup to keep the transmit and receive signals from interfering with each other on a single antenna, enabling simultaneous two-way communication. The other options don’t provide range extension: a scanner merely tunes across frequencies, a telemetry converter handles data formats, and the duplexer by itself doesn’t extend range but is a component used in systems like repeaters to separate transmission and reception.