Technician exam question T3A04
Subelement T3, RADIO WAVE PROPAGATION· Group T3A
What is the effect of antenna cross-polarization over a line-of-sight VHF or UHF path?
- A.Modulation sidebands might become inverted
- B.Received signal strength is reduced (correct answer)
- C.Signals have an echo effect
- D.Nothing significant will happen
WhyAntenna cross-polarization over a line-of-sight VHF or UHF path reduces received signal strength. Since VHF/UHF signals largely retain the polarization they were transmitted with over a direct line-of-sight path, a transmitting antenna polarized differently from the receiving antenna, cross-polarization, couples much less signal into the receiver, reducing received strength, sometimes substantially, answer B. It doesn't invert sidebands (A), it doesn't create an echo (C), and the effect is real and often significant, not negligible (D).
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.
Related questions
- T3A01Why do VHF signal strengths sometimes vary greatly when the antenna is moved only a few feet?
- T3A02How does vegetation affect UHF and microwave signals?
- T3A03What antenna polarization is normally used for long-distance CW and SSB contacts on the VHF and UHF bands?
- T3A05When using a directional antenna, how might your station be able to communicate with a distant repeater if buildings or obstructions are blocking the direct line of sight path?
- T3A06What is the meaning of the term “picket fencing”?