SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/ham-multipath-few-feet

Why can VHF signal strength change a lot when you move your antenna a few feet?

Multipath propagation cancels or reinforces the signal.

  1. Water vapor levels change along the path
  2. The Doppler effect shifts the frequency
  3. Multipath propagation cancels or reinforces signals ✔

Why: Signals bounce off buildings and hills and reach you by different paths. Depending on where your antenna is, those copies add together or cancel out.

Huh, didn't know that: Multipath also makes errors more likely in data transmissions.

The dad joke
Why did the ham keep dancing? He was chasing a better signal.
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Sources

  1. NCVEC 2026-2030 Technician Question Pool (Element 2), errata Feb 19, 2026 https://www.ncvec.org/downloads/2026-2030%20Technician%20Pool%20and%20Syllabus%20Public%20Release%20Feb%2019%202026.pdf

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