What creates intermodulation interference between two repeaters in close proximity?
The correct answer is B: The output signals mix in the final amplifier of one or both transmitters. What creates intermodulation interference between two repeaters in close proximity is that the output signals mix in the final amplifier of one or both transmitters. Repeater outputs can mix in the final amplifiers, creating IMD. For amateur radio operators, this is important for repeater operation. Understanding this helps when troubleshooting repeater interference.
Exam Tip
Intermodulation between repeaters = output signals mix in final amplifier of one or both transmitters. Think 'I'MD between 'R'epeaters = 'I'nterference 'M'ixing in 'D'evice (final amp). Repeater outputs can mix in the final amplifiers, creating IMD. Not feedback, not input frequencies, not harmonic relationship - just mixing in final amplifier.
Memory Aid
"Intermodulation between repeaters = output signals mix in final amplifier of one or both transmitters. Think 'I'MD between 'R'epeaters = 'M'ixing in 'F'inal amp. Repeater outputs can mix in the final amplifiers, creating IMD. Important for repeater operation."
Real-World Application
Intermodulation interference between two repeaters in close proximity: The output signals mix in the final amplifier of one or both transmitters. When repeaters are close, one repeater's output can enter another's final amplifier and mix, creating IMD products. This is what creates the interference - mixing in final amplifiers.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Output signals causing feedback in final amplifier isn't the cause - output signals mixing in final amplifier is the cause. Feedback isn't the cause.
Option C: Incorrect. Input frequencies being harmonically related isn't the cause - output signals mixing in final amplifier is the cause. Input frequencies isn't the cause.
Option D: Incorrect. Output frequencies being harmonically related isn't the cause - output signals mixing in final amplifier is the cause. Harmonic relationship isn't the cause.
题目解析
The correct answer is B: The output signals mix in the final amplifier of one or both transmitters. What creates intermodulation interference between two repeaters in close proximity is that the output signals mix in the final amplifier of one or both transmitters. Repeater outputs can mix in the final amplifiers, creating IMD. For amateur radio operators, this is important for repeater operation. Understanding this helps when troubleshooting repeater interference.
考试技巧
Intermodulation between repeaters = output signals mix in final amplifier of one or both transmitters. Think 'I'MD between 'R'epeaters = 'I'nterference 'M'ixing in 'D'evice (final amp). Repeater outputs can mix in the final amplifiers, creating IMD. Not feedback, not input frequencies, not harmonic relationship - just mixing in final amplifier.
记忆口诀
Intermodulation between repeaters = output signals mix in final amplifier of one or both transmitters. Think 'I'MD between 'R'epeaters = 'M'ixing in 'F'inal amp. Repeater outputs can mix in the final amplifiers, creating IMD. Important for repeater operation.
实际应用示例
Intermodulation interference between two repeaters in close proximity: The output signals mix in the final amplifier of one or both transmitters. When repeaters are close, one repeater's output can enter another's final amplifier and mix, creating IMD products. This is what creates the interference - mixing in final amplifiers.
错误选项分析
Option A: Incorrect. Output signals causing feedback in final amplifier isn't the cause - output signals mixing in final amplifier is the cause. Feedback isn't the cause. Option C: Incorrect. Input frequencies being harmonically related isn't the cause - output signals mixing in final amplifier is the cause. Input frequencies isn't the cause. Option D: Incorrect. Output frequencies being harmonically related isn't the cause - output signals mixing in final amplifier is the cause. Harmonic relationship isn't the cause.
知识点
Intermodulation interference, Two repeaters, Close proximity, Output signals mix, Final amplifier
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.