3-H-057: Frequency Modulation
3-57H1:
The deviation ratio is the:
Maximum carrier frequency deviation to the highest audio modulating frequency.
Audio modulating frequency to the center carrier frequency.
Carrier center frequency to the audio modulating frequency.
Highest audio modulating frequency to the average audio modulating frequency.
3-57H2:
What is the deviation ratio for an FM phone signal having a maximum frequency deviation of plus or minus 5 kHz and accepting a maximum modulation rate of 3 kHz?
1.66
60
0.16
0.6
3-57H3:
What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz and accepting a maximum modulation rate of 3.5 kHz?
2.14
0.214
0.47
47
3-57H4:
How can an FM-phone signal be produced in a transmitter?
By feeding the audio directly to the oscillator.
By modulating the supply voltage to a class-B amplifier.
By modulating the supply voltage to a class-C amplifier.
By using a balanced modulator.
3-57H5:
What is meant by the term modulation index?
The ratio between the deviation of a frequency modulated signal and the modulating frequency.
The processor index.
The FM signal-to-noise ratio.
The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency.
3-57H6:
In an FM-phone signal, what is the term for the maximum deviation from the carrier frequency divided by the maximum audio modulating frequency?
Deviation ratio.
Deviation index.
Modulation index.
Modulation ratio.
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