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15 Cards in this Set
- Front
- Back
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What is the difference between Phase Shift Keying and Freq Shift Keying?
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FSK the carrier frequency changes by a predetermined amount called the mark frequency Phase-shift keying is similar to FSK except that the phase, not the frequency, is shifted.
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What is the primary advantage
of PSK? |
can be accomplished in an amplifier stage.
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What type of Modulation is suited for use with communications systems incorporating time-division mutiplexing.
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Pulse Modulation
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What are the two advantages of CW communications?
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1. narrow bandwidth (requires less power out)
2. clarity (under high noise conditions) |
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What is the major disadvantages of CW communications?
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Must be turned on and
off at specific intervals to produce Morse code keying. and method is very slow. |
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In an AM transmitter, converts the audio frequency input to electrical energy.
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microphone
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In an AM transmitter, amplify the audio signal to the level required to modulate the
carrier fully |
driver and modulator
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In an AM transmitter, combines the rf carrier and the modulating signal to produce the AM signal for transmission.
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power amplifier
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In an FM transmitter, transmitter oscillator is maintained at a constant frequency by?
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quartz crystal
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The frequency of the carrier shifts according to audio signal variations by what in the FM transmitter?
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carrier phase-shift network
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The amount of variation from the carrier frequency depends
on? |
magnitude of the modulating signal
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The rate of variations in carrier frequency depends
on? |
frequency of the modulating signal
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FM transmitter is better than an AM transmitter for communications purposes because?
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FM is less affected by static and other types of interference
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What type of transmitter is the carrier is eliminated and the sideband frequencies produced by the carrier are reduced to a minimum.
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SINGLE-SIDEBAND TRANSMITTER
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What are advantages of SSB?
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narrower receiver
bandpass and the ability to place more signals in a small portion of the frequency spectrum |
