What makes HF scatter signals often sound distorted?
The correct answer is D: Energy is scattered into the skip zone through several different paths. What makes HF scatter signals often sound distorted is that energy is scattered into the skip zone through several different paths. Multiple reflection paths arrive at slightly different times, causing phase cancellation and distortion. For amateur radio operators, this explains why scatter signals are hard to copy. Understanding this helps explain scatter signal quality.
Exam Tip
HF scatter distortion = energy scattered through several different paths. Think 'S'catter = 'S'everal 'P'aths = 'S'ignal 'P'hase cancellation. Multiple reflection paths arrive at different times, causing phase cancellation and distortion. Not instability, not ground waves, not E region - just multiple paths.
Memory Aid
"HF scatter distortion = energy scattered through several different paths. Think 'S'catter = 'S'everal 'P'aths. Multiple reflection paths arrive at different times, causing phase cancellation and distortion. Key cause of scatter signal distortion."
Real-World Application
HF scatter signals are distorted because energy reaches the receiver through several different reflection paths. These paths have slightly different lengths and arrival times, causing phase cancellation when they combine. This creates the distorted, fluttering sound characteristic of scatter signals. The multiple paths are the cause of distortion.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Unstable ionospheric region isn't the main cause - it's the multiple paths that cause distortion. Stability isn't the key factor.
Option B: Incorrect. Ground waves aren't absorbing the signal - scatter is about multiple skywave paths, not ground wave absorption.
Option C: Incorrect. E region absence isn't the cause - scatter can occur with or without E region. Multiple paths are the cause.
题目解析
The correct answer is D: Energy is scattered into the skip zone through several different paths. What makes HF scatter signals often sound distorted is that energy is scattered into the skip zone through several different paths. Multiple reflection paths arrive at slightly different times, causing phase cancellation and distortion. For amateur radio operators, this explains why scatter signals are hard to copy. Understanding this helps explain scatter signal quality.
考试技巧
HF scatter distortion = energy scattered through several different paths. Think 'S'catter = 'S'everal 'P'aths = 'S'ignal 'P'hase cancellation. Multiple reflection paths arrive at different times, causing phase cancellation and distortion. Not instability, not ground waves, not E region - just multiple paths.
记忆口诀
HF scatter distortion = energy scattered through several different paths. Think 'S'catter = 'S'everal 'P'aths. Multiple reflection paths arrive at different times, causing phase cancellation and distortion. Key cause of scatter signal distortion.
实际应用示例
HF scatter signals are distorted because energy reaches the receiver through several different reflection paths. These paths have slightly different lengths and arrival times, causing phase cancellation when they combine. This creates the distorted, fluttering sound characteristic of scatter signals. The multiple paths are the cause of distortion.
错误选项分析
Option A: Incorrect. Unstable ionospheric region isn't the main cause - it's the multiple paths that cause distortion. Stability isn't the key factor. Option B: Incorrect. Ground waves aren't absorbing the signal - scatter is about multiple skywave paths, not ground wave absorption. Option C: Incorrect. E region absence isn't the cause - scatter can occur with or without E region. Multiple paths are the cause.
知识点
HF scatter, Multiple paths, Signal distortion, Skip zone
Verified Content
Question from official FCC General Class question pool. Explanation reviewed by licensed amateur radio operators.