Which of the following noise figure values is typical of a low-noise UHF preamplifier?
The correct answer is A: 0.5 dB. Which of the following noise figure values is typical of a low-noise UHF preamplifier is 0.5 dB. Low-noise UHF preamps typically have noise figures around 0.5 dB. For amateur radio operators, this is important for receiver design. Understanding this helps when evaluating preamplifiers.
Exam Tip
Low-noise UHF preamp noise figure = 0.5 dB. Think 'L'ow-'N'oise 'U'HF = '0'.5 dB. Low-noise UHF preamps typically have noise figures around 0.5 dB. Not -10 dB (invalid), not 44 dBm (power), not -20 dBm (power) - just 0.5 dB.
Memory Aid
"Low-noise UHF preamp noise figure = 0.5 dB. Think 'L'ow-'N'oise = '0'.5 dB. Low-noise UHF preamps typically have noise figures around 0.5 dB. Important for receiver design."
Real-World Application
A low-noise UHF preamplifier: A typical noise figure value is 0.5 dB. This is very low noise, making it suitable for weak signal reception. This is the value - 0.5 dB noise figure.
Key Concepts
Why Other Options Are Wrong
Option B (-10 dB): Incorrect. -10 dB isn't a valid noise figure - noise figure is positive. -10 dB is wrong.
Option C (44 dBm): Incorrect. 44 dBm is a power level, not noise figure - noise figure is in dB. 44 dBm is wrong.
Option D (-20 dBm): Incorrect. -20 dBm is a power level, not noise figure - noise figure is in dB. -20 dBm is wrong.
题目解析
The correct answer is A: 0.5 dB. Which of the following noise figure values is typical of a low-noise UHF preamplifier is 0.5 dB. Low-noise UHF preamps typically have noise figures around 0.5 dB. For amateur radio operators, this is important for receiver design. Understanding this helps when evaluating preamplifiers.
考试技巧
Low-noise UHF preamp noise figure = 0.5 dB. Think 'L'ow-'N'oise 'U'HF = '0'.5 dB. Low-noise UHF preamps typically have noise figures around 0.5 dB. Not -10 dB (invalid), not 44 dBm (power), not -20 dBm (power) - just 0.5 dB.
记忆口诀
Low-noise UHF preamp noise figure = 0.5 dB. Think 'L'ow-'N'oise = '0'.5 dB. Low-noise UHF preamps typically have noise figures around 0.5 dB. Important for receiver design.
实际应用示例
A low-noise UHF preamplifier: A typical noise figure value is 0.5 dB. This is very low noise, making it suitable for weak signal reception. This is the value - 0.5 dB noise figure.
错误选项分析
Option B (-10 dB): Incorrect. -10 dB isn't a valid noise figure - noise figure is positive. -10 dB is wrong. Option C (44 dBm): Incorrect. 44 dBm is a power level, not noise figure - noise figure is in dB. 44 dBm is wrong. Option D (-20 dBm): Incorrect. -20 dBm is a power level, not noise figure - noise figure is in dB. -20 dBm is wrong.
知识点
Noise figure values, Low-noise UHF preamplifier, 0.5 dB
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.