Deep Dive: G7B07
The correct answer is D: A filter and an amplifier operating in a feedback loop. The basic components of a sine wave oscillator are a filter and an amplifier operating in a feedback loop. Oscillators use positive feedback with frequency-selective filtering to generate sine waves. For amateur radio operators, this is how oscillators work. Understanding this helps when designing oscillators.
Why Other Answers Are Wrong
Option A: Incorrect. Oscillators don't use an amplifier and divider - dividers reduce frequency, not generate oscillations. Divider isn't a basic component. Option B: Incorrect. Oscillators don't use a frequency multiplier and mixer - multipliers increase frequency, mixers combine signals. These aren't basic oscillator components. Option C: Incorrect. Oscillators don't use a circulator and filter in feed-forward - oscillators use feedback, not feed-forward. Circulator and feed-forward aren't oscillator components.
Exam Tip
Sine wave oscillator = filter and amplifier in feedback loop. Think 'O'scillator = 'O'scillates with 'F'eedback 'A'mplifier and 'F'ilter. Uses positive feedback with frequency-selective filtering to generate sine waves. Not divider, not multiplier/mixer, not circulator - just filter and amplifier in feedback.
Memory Aid
Sine wave oscillator = filter and amplifier in feedback loop. Think 'O'scillator = 'F'eedback 'A'mplifier and 'F'ilter. Uses positive feedback with frequency-selective filtering to generate sine waves. Basic oscillator structure.
Real-World Example
A sine wave oscillator: An amplifier provides gain, and a filter (like an LC tank circuit) selects the frequency. They're connected in a feedback loop - the filter's output feeds back to the amplifier input. This creates sustained oscillation at the filter's resonant frequency. This is how oscillators work.
Source & Coverage
Question Pool: 2023-2027 Question Pool
Subelement: G7B
Reference: 2023-2027 Question Pool · G7 - Practical Circuits
Key Concepts
Verified Content
Question from the official FCC General Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the G7B topic.