General exam question G8B07
Subelement G8, SIGNALS AND EMISSIONS· Group G8B
What is the frequency deviation for a 12.21 MHz reactance modulated oscillator in a 5 kHz deviation, 146.52 MHz FM phone transmitter?
- A.101.75 Hz
- B.416.7 Hz (correct answer)
- C.5 kHz
- D.60 kHz
WhyA 12.21 MHz reactance modulated oscillator in a 5 kHz deviation, 146.52 MHz FM phone transmitter has a frequency deviation of about 416.7 Hz. The multiplier stages between a 12.21 MHz reactance-modulated oscillator and a 146.52 MHz final output multiply the frequency by 146.52 divided by 12.21, which is 12, and since deviation gets multiplied by that same factor, the oscillator's own deviation must be the final 5 kHz divided by 12, about 416.7 Hz, answer B. The other values don't match dividing the target 5 kHz final deviation by the actual 12x multiplication factor between these two frequencies.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2023-2027 NCVEC Element 3 pool (public domain); the explanation above is original writing, see our methodology.
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