Technician exam question T3C01
Subelement T3, RADIO WAVE PROPAGATION· Group T3C
Why are simplex UHF signals rarely heard beyond their radio horizon?
- A.They are too weak to go very far
- B.FCC regulations prohibit them from going more than 50 miles
- C.UHF signals are usually not propagated by the ionosphere (correct answer)
- D.UHF signals are absorbed by the ionospheric D region
WhySimplex UHF signals are rarely heard beyond their radio horizon because UHF signals usually aren't propagated by the ionosphere. UHF frequencies are high enough that the ionosphere doesn't reflect them back to Earth the way it does HF signals, so simplex UHF contacts are essentially limited to the radio horizon, the roughly line-of-sight range where the signal can still reach a receiver before the Earth's curvature and terrain block it, answer C. UHF signals aren't inherently too weak (A), there's no FCC distance cap on simplex operation (B), and the ionospheric D region absorbs and attenuates signals rather than acting as the reason UHF fails to travel further, so D mischaracterizes the mechanism.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2026-2030 NCVEC Element 2 pool (public domain); the explanation above is original writing, see our methodology.
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