Deep Dive: G8B04
The correct answer is D: Multiplier. The stage in a VHF FM transmitter that generates a harmonic of a lower frequency signal to reach the desired operating frequency is a multiplier. Multipliers multiply the frequency (e.g., 2×, 3×) to reach higher frequencies. For amateur radio operators, this is how VHF transmitters work. Understanding this helps when designing transmitters.
Why Other Answers Are Wrong
Option A (Mixer): Incorrect. Mixers combine frequencies (sum/difference), they don't multiply to generate harmonics - multipliers multiply frequency. Mixers are different. Option B (Reactance modulator): Incorrect. Reactance modulators vary phase for modulation, they don't multiply frequency - multipliers multiply frequency. Reactance modulators are different. Option C (Balanced converter): Incorrect. Balanced converters are for frequency conversion, not multiplication - multipliers multiply frequency. Balanced converters are different.
Exam Tip
VHF FM transmitter harmonic generation = multiplier. Think 'M'ultiplier = 'M'ultiplies frequency to reach 'M'uch higher frequencies. Multipliers multiply frequency (2×, 3×) to reach desired operating frequency. Not mixer, not reactance modulator, not balanced converter - just multiplier.
Memory Aid
VHF FM transmitter harmonic generation = multiplier. Think 'M'ultiplier = 'M'ultiplies frequency. Multipliers multiply frequency (2×, 3×) to reach desired operating frequency. Used to reach VHF from lower frequencies.
Real-World Example
A VHF FM transmitter: A 12.21 MHz oscillator feeds a multiplier (e.g., 12× multiplier). The multiplier generates harmonics, producing 146.52 MHz (12.21 × 12 = 146.52). Multipliers are used to reach VHF frequencies from lower-frequency oscillators. This is how VHF transmitters generate their operating frequency.
Source & Coverage
Question Pool: 2023-2027 Question Pool
Subelement: G8B
Reference: 2023-2027 Question Pool · G8 - Signals and Emissions
Key Concepts
Verified Content
Question from the official FCC General Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the G8B topic.