B-001-19: Amplitude modulation, frequency stability, measurements
B-001-19-01:
When operating on frequencies below 148 MHz:
over a period of one hour the frequency stability must be comparable to crystal control
the bandwidth for any emission must not exceed 3 kHz
the frequency stability of the transmitter must be at least two parts per million
an overmodulation indicator must be used
B-001-19-02:
A reliable means to prevent or indicate overmodulation must be employed at an amateur station if:
radiotelephony is used
DC input power to the anode or collector circuit of the final RF stage is in excess of 250 watts
radiotelegraphy is used
persons other than the licensee use the station
B-001-19-03:
An amateur station using radiotelephony must install a device for indicating or preventing:
overmodulation
resonance
antenna power
plate voltage
B-001-19-04:
The maximum percentage of modulation permitted in the use of radiotelephony by an amateur station is:
100 percent
75 percent
50 percent
90 percent
B-001-19-05:
All amateur stations, regardless of the mode of transmission used, must be equipped with:
a reliable means of determining the operating radio frequency
a DC power meter
an overmodulation indicating device
a dummy antenna
B-001-19-06:
The maximum percentage of modulation permitted in the use of radiotelephony by an amateur station is:
100 percent
90 percent
75 percent
50 percent
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Color key:
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● = Unseen
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● = Weak
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● = Review
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● = Learned
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● = Incorrect answer
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