Question T7B02
From subelement T7 - T7B
What would cause a broadcast AM or FM radio to receive an amateur radio transmission unintentionally?
Why is this correct?
Option A is correct because fundamental overload occurs when a strong amateur signal overwhelms a broadcast receiver's front-end circuitry, making it unable to reject signals outside its intended band. The receiver gets 'shouted down' by the nearby powerful signal. Options B, C, and D describe transmitter problems that would affect signal quality but wouldn't cause cross-band interference into broadcast receivers.
Memory tip
Look for the receiver's perspective in interference questions. When amateur signals appear on broadcast radios, the problem is always receiver overload, not transmitter settings. The key pattern: strong nearby signals can overwhelm any receiver's selectivity, regardless of frequency separation.
Learn more
Fundamental overload represents a classic RF compatibility challenge in amateur radio operation. Unlike harmonic interference where spurious emissions cause problems, fundamental overload involves your clean, legal signal being too strong for nearby consumer electronics. This highlights why Part 97.307(f) requires amateurs to use good engineering practices to minimize interference potential, even when operating within emission standards and frequency privileges.
Think about it
Why do you think fundamental overload affects the receiver rather than being solved by transmitter adjustments, and what does this tell you about RF system design?