What does an S meter measure?
The correct answer is C: Received signal strength. What an S meter measures is received signal strength. S meters indicate how strong received signals are, typically on a scale of S1-S9 plus dB over S9. For amateur radio operators, this helps assess signal quality. Understanding this helps when reading S meters.
Exam Tip
S meter measures = received signal strength. Think 'S' meter = 'S'trength meter (received signal). Indicates how strong received signals are, typically S1-S9 plus dB over S9. Not carrier suppression, not impedance, not power output - just received signal strength.
Memory Aid
"S meter measures = received signal strength. Think 'S' meter = 'S'trength meter. Indicates how strong received signals are, typically S1-S9 plus dB over S9. Helps assess signal quality and propagation."
Real-World Application
You receive a signal and the S meter reads S7. This indicates the received signal strength is S7 (moderately strong). If it reads S9+20 dB, the signal is very strong (20 dB over S9). S meters help you assess signal quality and propagation conditions.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. S meters don't measure carrier suppression - that requires specialized equipment. Carrier suppression is a transmitter parameter.
Option B: Incorrect. S meters don't measure impedance - that requires impedance meters. Impedance is a different parameter.
Option D: Incorrect. S meters don't measure transmitter power output - that requires power meters. Power output is a transmitter parameter.
题目解析
The correct answer is C: Received signal strength. What an S meter measures is received signal strength. S meters indicate how strong received signals are, typically on a scale of S1-S9 plus dB over S9. For amateur radio operators, this helps assess signal quality. Understanding this helps when reading S meters.
考试技巧
S meter measures = received signal strength. Think 'S' meter = 'S'trength meter (received signal). Indicates how strong received signals are, typically S1-S9 plus dB over S9. Not carrier suppression, not impedance, not power output - just received signal strength.
记忆口诀
S meter measures = received signal strength. Think 'S' meter = 'S'trength meter. Indicates how strong received signals are, typically S1-S9 plus dB over S9. Helps assess signal quality and propagation.
实际应用示例
You receive a signal and the S meter reads S7. This indicates the received signal strength is S7 (moderately strong). If it reads S9+20 dB, the signal is very strong (20 dB over S9). S meters help you assess signal quality and propagation conditions.
错误选项分析
Option A: Incorrect. S meters don't measure carrier suppression - that requires specialized equipment. Carrier suppression is a transmitter parameter. Option B: Incorrect. S meters don't measure impedance - that requires impedance meters. Impedance is a different parameter. Option D: Incorrect. S meters don't measure transmitter power output - that requires power meters. Power output is a transmitter parameter.
知识点
S meter, Received signal strength, Signal strength, Receiver features
Verified Content
Question from official FCC General Class question pool. Explanation reviewed by licensed amateur radio operators.