A-005-05: FM deviation, modulation index, deviation ratio, deviation meter
A-005-05-01:
In an FM phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency, what is the modulation index, when the modulating frequency is 1000 Hz?
3
0.3
3000
1000
A-005-05-02:
What is the modulation index of an FM phone transmitter producing an instantaneous carrier deviation of 6 kHz when modulated with a 2 kHz modulating frequency?
3
0.333
2000
6000
A-005-05-03:
What is the deviation ratio of an FM phone signal having a maximum frequency swing of plus or minus 5 kHz and accepting a maximum modulation rate of 3 kHz?
1.66
60
0.16
0.6
A-005-05-04:
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
0.47
47
0.214
A-005-05-05:
When the transmitter is not modulated, or the amplitude of the modulating signal is zero, the frequency of the carrier is called its:
centre frequency
frequency deviation
frequency shift
modulating frequency
A-005-05-06:
In a FM transmitter system, the number of cycles of deviation from the centre frequency is determined solely by the:
amplitude of the modulating frequency
frequency of the modulating frequency
amplitude and the frequency of the modulating frequency
modulating frequency and the amplitude of the centre frequency
A-005-05-07:
Any FM wave with single-tone modulation has:
an infinite number of sideband frequencies
two sideband frequencies
four sideband frequencies
one sideband frequency
A-005-05-08:
The deviation meter works on the principle of:
a carrier null and multiplying the modulation frequency by the modulation index
detecting the frequencies in the sidebands
the amplitude of power in the sidebands
a carrier peak and dividing by the modulation index
A-005-05-09:
When using a deviation meter, it is important to know:
modulating frequency and the modulation index
modulation index
modulating frequency
pass-band of the IF filter
A-005-05-10:
What is the total bandwidth of an FM-phone transmission having a 5-kHz deviation and a 3-kHz modulating frequency?
16 kHz
8 kHz
5 kHz
3 kHz
A-005-05-11:
What is the frequency deviation for a 12.21-MHz reactance-modulated oscillator in a 5-kHz deviation, 146.52-MHz FM-phone transmitter?
416.7 Hz
12 kHz
5 kHz
41.67 Hz
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