General exam question G4A08
Subelement G4, AMATEUR RADIO PRACTICES· Group G4A
What is the correct adjustment for the LOAD or COUPLING control of a vacuum tube RF power amplifier?
- A.Minimum SWR on the antenna
- B.Minimum plate current without exceeding maximum allowable grid current
- C.Highest plate voltage while minimizing grid current
- D.Desired power output without exceeding maximum allowable plate current (correct answer)
WhyThe LOAD or COUPLING control of a vacuum tube RF power amplifier is correctly adjusted for the desired power output without exceeding the maximum allowable plate current. The LOAD or COUPLING control on a vacuum-tube RF power amplifier sets how tightly the tank circuit couples into the antenna system, and it's correctly adjusted by dialing in the desired power output while watching that plate current never exceeds the tube's maximum rating, answer D. Minimum SWR on the antenna is a feed-line property the LOAD control doesn't directly set, and neither minimizing plate current nor maximizing plate voltage describes what this control is actually used for.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2023-2027 NCVEC Element 3 pool (public domain); the explanation above is original writing, see our methodology.
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