E1B08: What limitations may the FCC place on an amateur station if its signa…

E1B08§ 97.121E1B →

What limitations may the FCC place on an amateur station if its signal causes interference to domestic broadcast reception, assuming that the receivers involved are of good engineering design?

AThe amateur station must cease operation
BThe amateur station must cease operation on all frequencies below 30 MHz
CThe amateur station must cease operation on all frequencies above 30 MHz
DThe amateur station must avoid transmitting during certain hours on frequencies that cause the interference

Why Section 97.121 covers restricted operation. If an amateur station interferes with reception of a broadcast station by receivers of good engineering design, the FCC can require the amateur to stop transmitting on the offending frequencies only during the hours when that broadcast reception is normally desired, commonly called quiet hours. The rule targets the specific frequencies and specific times involved, not the station as a whole, and it only applies when the affected receiver is reasonably well designed.

Watch out The choices that shut the station down entirely or ban everything below or above 30 MHz go far beyond what 97.121 authorizes; the FCC restricts only the frequencies causing the problem, and only during certain hours.

Think 'quiet hours,' not shutdown: limited frequencies, limited times.

HamSandwich explanation, first draft. The question and answers are the NCVEC text.

47 CFR 97.121 Restricted operation.

(a) If the operation of an amateur station causes general interference to the reception of transmissions from stations operating in the domestic broadcast service when receivers of good engineering design, including adequate selectivity characteristics, are used to receive such transmissions, and this fact is made known to the amateur station licensee, the amateur station shall not be operated during the hours from 8 p.m. to 10:30 p.m., local time, and on Sunday for the additional period from 10:30 a.m. until 1 p.m., local time, upon the frequency or frequencies used when the interference is created.

(b) In general, such steps as may be necessary to minimize interference to stations operating in other services may be required after investigation by the FCC.

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

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