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SESK: Stuff Everyone Should Know · sesk.info/hamg-pep-output

How does the FCC measure the maximum power an amateur station may use?

PEP output from the transmitter.

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  1. PEP output from the transmitter ✔
  2. RMS output from the transmitter
  3. PEP input to the antenna

Why: The rules limit peak envelope power (PEP) at the transmitter output. They do not measure at the antenna, so feed line loss does not count against the limit.

Huh, didn't know that: PEP is the average power over one RF cycle at the crest of the modulation envelope, per 97.3(b)(9).

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References

Answer: PEP output from the transmitter. The rules limit peak envelope power (PEP) at the transmitter output. They do not measure at the antenna, so feed line loss does not count against the limit.

  1. NCVEC 2023-2027 General Class Pool and Syllabus (6th Errata, Feb 4 2026) ncvec.org/downloads/General%20Class%20Pool%20and%20Syllabus%202023-2027%20Public%20Release%20with%206th%20Errata%20Feb%204%202026.pdf
    PEP output from the transmitter
    Checked 2026-10-10.
  2. 47 CFR 97.3 (Cornell LII mirror of eCFR) www.law.cornell.edu/cfr/text/47/97.3
    The average power supplied to the antenna transmission line by a transmitter during one RF cycle at the crest of the modulation envelope
    Checked 2026-10-10.

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