Which radio is commonly carried by responders and operates in simplex mode?

• A. Portable Radio
• B. Mobile Radio
• C. Duplex Radio
• D. Satellite Radio

Answer: (A)

Responders rely on handheld devices that they can carry on-scene, move with, and use quickly for immediate communication. Simplex operation means using one frequency channel for both transmitting and receiving, with the ability to talk and listen in half-duplex fashion—typically you press the button to speak and release to listen. A handheld portable radio is designed for this: it's compact, battery-powered, and built for direct, on-the-spot communication among team members and incident command without needing vehicle equipment or network infrastructure. This makes it the most practical tool for rapid, local coordination during emergencies. In contrast, a mobile radio is mounted in a vehicle and often relies on repeaters for range, a duplex system uses separate frequencies for transmit and receive, and satellite radios depend on satellite links—not ideal for the quick, close-range exchanges typical on-scene.