What are three common oscillator circuits?
The correct answer is D: Colpitts, Hartley, and Pierce. Three common oscillator circuits are the Colpitts, Hartley, and Pierce oscillators. These are fundamental oscillator topologies used in radio frequency circuits.
The Colpitts oscillator uses a capacitive voltage divider for feedback, the Hartley oscillator uses a tapped inductor (autotransformer) for feedback, and the Pierce oscillator uses a crystal for frequency control. These three oscillators are among the most commonly used in amateur radio equipment. They're used in transmitters, receivers, and frequency synthesizers to generate stable RF signals. Each has different characteristics that make them suitable for different applications.
Exam Tip
Common oscillators = Colpitts, Hartley, Pierce. Remember: The three common oscillator circuits are Colpitts (capacitive divider), Hartley (tapped inductor), and Pierce (crystal).
Memory Aid
"**C**ommon **O**scillators = **C**olpitts, **H**artley, **P**ierce (think 'CO = CHP')"
Real-World Application
You're building a VFO (Variable Frequency Oscillator) for your transmitter. You might use a Colpitts oscillator for its simplicity and good frequency stability. For crystal-controlled oscillators, you'd use a Pierce oscillator. The Hartley oscillator is another option that uses a tapped coil for feedback. These three are the workhorses of RF oscillator design.
FCC Part 97.3Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. 'Taft' is not a standard oscillator circuit name. The correct combination is Colpitts, Hartley, and Pierce.
Option B: Incorrect. 'Fenner' and 'Beane' are not standard oscillator circuit names. The correct names are Colpitts, Hartley, and Pierce.
Option C: Incorrect. 'Taft' is not a standard oscillator circuit. The correct combination is Colpitts, Hartley, and Pierce.
题目解析
The correct answer is D: Colpitts, Hartley, and Pierce. Three common oscillator circuits are the Colpitts, Hartley, and Pierce oscillators. These are fundamental oscillator topologies used in radio frequency circuits. The Colpitts oscillator uses a capacitive voltage divider for feedback, the Hartley oscillator uses a tapped inductor (autotransformer) for feedback, and the Pierce oscillator uses a crystal for frequency control. These three oscillators are among the most commonly used in amateur radio equipment. They're used in transmitters, receivers, and frequency synthesizers to generate stable RF signals. Each has different characteristics that make them suitable for different applications.
考试技巧
Common oscillators = Colpitts, Hartley, Pierce. Remember: The three common oscillator circuits are Colpitts (capacitive divider), Hartley (tapped inductor), and Pierce (crystal).
记忆口诀
**C**ommon **O**scillators = **C**olpitts, **H**artley, **P**ierce (think 'CO = CHP')
实际应用示例
You're building a VFO (Variable Frequency Oscillator) for your transmitter. You might use a Colpitts oscillator for its simplicity and good frequency stability. For crystal-controlled oscillators, you'd use a Pierce oscillator. The Hartley oscillator is another option that uses a tapped coil for feedback. These three are the workhorses of RF oscillator design.
错误选项分析
Option A: Incorrect. 'Taft' is not a standard oscillator circuit name. The correct combination is Colpitts, Hartley, and Pierce. Option B: Incorrect. 'Fenner' and 'Beane' are not standard oscillator circuit names. The correct names are Colpitts, Hartley, and Pierce. Option C: Incorrect. 'Taft' is not a standard oscillator circuit. The correct combination is Colpitts, Hartley, and Pierce.
知识点
Oscillator circuits, Colpitts, Hartley, Pierce
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.