SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/ham-feedline-loss-heat

What happens to power lost in a feed line?

It is converted into heat.

  1. It is radiated as harmonics
  2. It increases the SWR
  3. It is converted into heat ✔

Why: Feed line loss does not disappear. The lost power warms up the cable's conductors and insulation, so less reaches the antenna.

Huh, didn't know that: An RF power meter belongs in the feed line, between the transmitter and the antenna.

The dad joke
Why was the coax cable always warm? It kept losing it.
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Sources

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

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