How can fundamental overload of a non-amateur radio or TV receiver by an amateur signal be reduced or eliminated?
The correct answer is A: Block the amateur signal with a filter at the antenna input of the affected receiver. Fundamental overload of a non-amateur radio or TV receiver by an amateur signal can be reduced or eliminated by blocking the amateur signal with a filter at the antenna input of the affected receiver. This is the correct approach because the problem is the receiver's inability to reject strong out-of-band signals. A filter (typically a band-pass filter for the desired service or a notch filter for the interfering frequency) blocks the amateur signal before it enters the receiver. For amateur radio operators, this is the proper solution - the interference is caused by receiver overload, so the filter goes on the affected receiver, not the transmitter.
Exam Tip
Fundamental overload = filter on affected receiver. Think 'F'ilter on 'F'aulty receiver. The receiver can't reject strong signals, so add filtering to the receiver's antenna input, not the transmitter.
Memory Aid
"Fundamental overload = filter on receiver. Think 'F'undamental overload = 'F'ilter on 'F'aulty receiver. Block the interfering signal at the receiver's antenna input."
Real-World Application
Your neighbor's TV picks up your 2-meter transmission because their TV receiver lacks filtering. The solution is to install a high-pass filter on their TV's antenna input, which blocks your 2-meter signal (144 MHz) while passing TV signals (54-806 MHz). This prevents your signal from overloading their receiver. Your transmitter is operating legally - their receiver needs the filter.
Key Concepts
Why Other Options Are Wrong
Option B: Incorrect. Blocking the signal at the transmitter doesn't help - you need to transmit your signal. The problem is the receiver picking up your legal signal, so the filter belongs on the receiver.
Option C: Incorrect. Switching modes doesn't solve fundamental overload - the receiver will still be overloaded by a strong signal regardless of mode.
Option D: Incorrect. Narrow-band modes don't prevent fundamental overload - the receiver is still overloaded by the strong signal's presence.
题目解析
The correct answer is A: Block the amateur signal with a filter at the antenna input of the affected receiver. Fundamental overload of a non-amateur radio or TV receiver by an amateur signal can be reduced or eliminated by blocking the amateur signal with a filter at the antenna input of the affected receiver. This is the correct approach because the problem is the receiver's inability to reject strong out-of-band signals. A filter (typically a band-pass filter for the desired service or a notch filter for the interfering frequency) blocks the amateur signal before it enters the receiver. For amateur radio operators, this is the proper solution - the interference is caused by receiver overload, so the filter goes on the affected receiver, not the transmitter.
考试技巧
Fundamental overload = filter on affected receiver. Think 'F'ilter on 'F'aulty receiver. The receiver can't reject strong signals, so add filtering to the receiver's antenna input, not the transmitter.
记忆口诀
Fundamental overload = filter on receiver. Think 'F'undamental overload = 'F'ilter on 'F'aulty receiver. Block the interfering signal at the receiver's antenna input.
实际应用示例
Your neighbor's TV picks up your 2-meter transmission because their TV receiver lacks filtering. The solution is to install a high-pass filter on their TV's antenna input, which blocks your 2-meter signal (144 MHz) while passing TV signals (54-806 MHz). This prevents your signal from overloading their receiver. Your transmitter is operating legally - their receiver needs the filter.
错误选项分析
Option B: Incorrect. Blocking the signal at the transmitter doesn't help - you need to transmit your signal. The problem is the receiver picking up your legal signal, so the filter belongs on the receiver. Option C: Incorrect. Switching modes doesn't solve fundamental overload - the receiver will still be overloaded by a strong signal regardless of mode. Option D: Incorrect. Narrow-band modes don't prevent fundamental overload - the receiver is still overloaded by the strong signal's presence.
知识点
Fundamental overload, Receiver filtering, Interference resolution, RFI mitigation
Verified Content
Question from official FCC Technician Class question pool. Explanation reviewed by licensed amateur radio operators.