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E1F11

COMMISSION RULES · Miscellaneous rules: external RF power amplifiers; prohibited communications; spread spectrum; auxiliary stations; Canadian amateurs operating in the US; special temporary authority

E1F11§ 97.317E1F →

Which of the following best describes one of the standards that must be met by an external RF power amplifier if it is to qualify for a grant of FCC certification?

  1. AIt must produce full legal output when driven by not more than 5 watts of mean RF input power
  2. BIt must have received an Underwriters Laboratory certification for electrical safety as well as having met IEEE standard 14.101(B)
  3. CIt must exhibit a gain of less than 23 dB when driven by 10 watts or less
  4. DIt must satisfy the FCC's spurious emission standards when operated at the lesser of 1500 watts or its full output power
Why Section 97.317 sets the certification standards for external RF power amplifiers sold to amateurs. The key test is that the amplifier must meet the FCC's spurious emission limits of 97.307(d) and (e) when it is operated at the lesser of 1500 watts PEP or its own maximum output power. In other words, it has to stay clean at the highest power it can legally be run at. The rule also requires that the amplifier not be capable of operating on frequencies between 26 and 28 MHz, which keeps certified ham amplifiers out of the illegal CB linear market.
Watch out The choices about specific drive levels or a gain figure sound like the old FCC criteria once used to identify CB-type linears, but neither a 5 watt drive requirement nor a 23 dB gain limit appears in 97.317 as a certification standard.
Certification test: clean spurs at 1500 W or full output, whichever is LESS, and no 26-28 MHz capability.
HamSandwich explanation, first draft. The question and answers are the NCVEC text.
47 CFR 97.317 Standards for certification of external RF power amplifiers.

(a) To receive a grant of certification, the amplifier must:

(1) Satisfy the spurious emission standards of § 97.307 (d) or (e) of this part, as applicable, when the amplifier is operated at the lesser of 1.5 kW PEP or its full output power and when the amplifier is placed in the “standby” or “off” positions while connected to the transmitter.

(2) Not be capable of amplifying the input RF power (driving signal) by more than 15 dB gain. Gain is defined as the ratio of the input RF power to the output RF power of the amplifier where both power measurements are expressed in peak envelope power or mean power.

(3) Exhibit no amplification (0 dB gain) between 26 MHz and 28 MHz.

(b) Certification shall be denied when:

(1) The Commission determines the amplifier can be used in services other than the Amateur Radio Service, or

(2) The amplifier can be easily modified to operate on frequencies between 26 MHz and 28 MHz.

eCFR text as of 1 Sep 2026 · read on ecfr.gov
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The rest of E1F

  1. E1F01 On what frequencies are spread spectrum transmissions permitted?
  2. E1F02 What privileges are authorized in the US to persons holding an amateur service license granted by the governm…
  3. E1F03 Under what circumstances may a dealer sell an external RF power amplifier capable of operation below 144 MHz …
  4. E1F04 Which of the following geographic descriptions approximately describes "Line A"?
  5. E1F05 Amateur stations may not transmit in which of the following frequency segments if they are located in the con…
  6. E1F06 Under what circumstances might the FCC issue a Special Temporary Authority (STA) to an amateur station?
  7. E1F07 When may an amateur station send a message to a business?
  8. E1F08 Which of the following types of amateur station communications are prohibited?
  9. E1F09 Which of the following cannot be transmitted over an amateur radio mesh network?
  10. E1F10 Who may be the control operator of an auxiliary station?
  11. E1F11 Which of the following best describes one of the standards that must be met by an external RF power amplifier…
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