A11 and A12 are conventional simplex radio frequencies used for short-range communication within distances of 1 mile. Which option describes this?

• A. Digital trunked frequencies used for broader coverage
• B. Long-range HF frequencies
• C. Satellite communications used for remote dispatch
• D. Conventional simplex radio frequencies used for short-range communication within distances of 1 mile

Answer: (D)

Simplex operation uses the same frequency for both transmit and receive, allowing direct, on-scene communication without a repeater. When you have conventional simplex frequencies, they’re intended for short-range use, typically within about a mile, though actual range depends on power, terrain, and obstacles. The description of A11 and A12 as conventional simplex frequencies fits this exact scenario: direct, one-frequency communication over a short distance, without the complexity of trunking, long-range propagation, or satellite links. The other options describe different systems—digital trunking with broader coverage, long-range HF channels, or satellite communications—none of which match the given short-range, on-frequency, direct-talk setup.