Question
What would cause a broadcast AM or FM radio to receive an amateur radio transmission unintentionally?
Answer Options
- A) The receiver is unable to reject strong signals outside the AM or FM band
- B) The microphone gain of the transmitter is turned up too high
- C) The audio amplifier of the transmitter is overloaded
- D) The deviation of an FM transmitter is set too low
Correct Answer: A
Explanation
This type of interference (often called \text{BCI} for broadcast interference) is typically caused by a flaw in the affected non-amateur device, not the amateur radio transmitter. It happens when the amateur station is operating near a broadcast receiver (like a neighbor’s stereo) that is not properly shielded or designed.
The receiver’s circuitry is designed to only pick up signals in the broadcast band, but if the amateur signal is extremely strong, the receiver’s front-end cannot cope. The receiver is unable to reject strong signals outside the AM or FM band, and the unwanted amateur signal is demodulated (turned into audio) by the receiver, a phenomenon known as fundamental overload (T7B03).
This topic was automatically created to facilitate community discussion about this exam question. Feel free to share study tips, memory tricks, or additional explanations!