Radio Wave Propagation

5 free sample questions of the 35 in this topic. The full set is in the app.

1. Question 1

   Why do VHF signal strengths sometimes vary greatly when the antenna is moved only a few feet?

   • A.The signal path encounters different concentrations of water vapor
   • B.VHF ionospheric propagation is very sensitive to path length
   • C.Multipath propagation cancels or reinforces signals
   • D.The Doppler effect causes slight frequency shifts which result in changes in signal strength
   Show answer & explanation

   Answer: C. Multipath propagation cancels or reinforces signals

   Multipath propagation cancels or reinforces signals. (NCVEC T3A)

   Source: 2026-2030 Technician Class FCC Element 2 Question Pool and Syllabus — Subelement T3, Group T3A, Question T3A01

2. Question 2

   How does vegetation affect UHF and microwave signals?

   • A.Causes knife-edge diffraction, distorting voice peaks
   • B.Absorbs signals, leading to poor reception of weak signals
   • C.Amplifies signals, improving reception of weak signals
   • D.Has no effect
   Show answer & explanation

   Answer: B. Absorbs signals, leading to poor reception of weak signals

   Absorbs signals, leading to poor reception of weak signals. (NCVEC T3A)

   Source: 2026-2030 Technician Class FCC Element 2 Question Pool and Syllabus — Subelement T3, Group T3A, Question T3A02

3. Question 3

   What antenna polarization is normally used for long-distance CW and SSB contacts on the VHF and UHF bands?

   • A.Right-hand circular
   • B.Left-hand circular
   • C.Horizontal
   • D.Vertical
   Show answer & explanation

   Answer: C. Horizontal

   Horizontal. (NCVEC T3A)

   Source: 2026-2030 Technician Class FCC Element 2 Question Pool and Syllabus — Subelement T3, Group T3A, Question T3A03

4. Question 4

   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
   • C.Signals have an echo effect
   • D.Nothing significant will happen
   Show answer & explanation

   Answer: B. Received signal strength is reduced

   Received signal strength is reduced. (NCVEC T3A)

   Source: 2026-2030 Technician Class FCC Element 2 Question Pool and Syllabus — Subelement T3, Group T3A, Question T3A04

5. Question 5

   When 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?

   • A.Change from vertical to horizontal polarization
   • B.Try to find a path that reflects signals to the repeater
   • C.Try the long path
   • D.Increase the antenna SWR
   Show answer & explanation

   Answer: B. Try to find a path that reflects signals to the repeater

   Try to find a path that reflects signals to the repeater. (NCVEC T3A)

   Source: 2026-2030 Technician Class FCC Element 2 Question Pool and Syllabus — Subelement T3, Group T3A, Question T3A05

30 more Radio Wave Propagation questions are in the app, along with explanations and flashcards for every one.

OnAir is an independent study aid based on the NCVEC 2026-2030 Technician Class question pool and 47 CFR Part 97. It is not affiliated with, endorsed by, or sponsored by the FCC, NCVEC, ARRL, or any government agency.