Antennas

Which of the following could cause a high standing wave ratio on a transmission line?

Answer

A detuned antenna coupler.

A detuned antenna or coupler is a mismatch that reflects power back down the feed line, raising the standing-wave ratio (SWR).

Source: FCC Element 3 question pool, 3J

Not the answer

  • Excessive modulation.
  • Low power from the transmitter.
  • An increase in output power.

Practice this

The FCC Element 3 (General Radiotelephone) exam is 100 questions and takes 75 correct — 75% — to pass. Element 1, the other half of the licence, is 24 questions and takes 18 correct. The app’s page carries a free ten-question test drawn from the same bank, marked as you go.

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