Radio Receivers The frequency generated by each decade in a direct frequency synthesizer is much higher than the frequency shown; this is done to Increase the frequency stability of the synthesizer Reduce the number of crystals required Reduce the number of decades Reduce the spurious frequency problem Increase the frequency stability of the synthesizer Reduce the number of crystals required Reduce the number of decades Reduce the spurious frequency problem ANSWER DOWNLOAD EXAMIANS APP
Radio Receivers In a radio receiver with simple AGC The faster the AGC time constant the more accurate the output The audio stage gain is normally controlled by the AGC An increase in signal strength produces more AGC The highest AGC voltage is produced The faster the AGC time constant the more accurate the output The audio stage gain is normally controlled by the AGC An increase in signal strength produces more AGC The highest AGC voltage is produced ANSWER DOWNLOAD EXAMIANS APP
Radio Receivers In a ratio detector the circuit is the same as in a discriminator, except that the diodes are reversed stabilization against signal strength variations is provided the output is twice that obtainable from a similar phase discriminator the linearity is worse than in phase discriminator the circuit is the same as in a discriminator, except that the diodes are reversed stabilization against signal strength variations is provided the output is twice that obtainable from a similar phase discriminator the linearity is worse than in phase discriminator ANSWER DOWNLOAD EXAMIANS APP
Radio Receivers In a broadcast superheterodyne receiver, the RF amplifier normally works at 455 kHz above the carrier frequency Local oscillator frequency is normally double the IF Local oscillator operates below the signal frequency Mixer input must be tuned to the signal frequency RF amplifier normally works at 455 kHz above the carrier frequency Local oscillator frequency is normally double the IF Local oscillator operates below the signal frequency Mixer input must be tuned to the signal frequency ANSWER DOWNLOAD EXAMIANS APP
Radio Receivers The typical squelch circuit cuts off An IF amplifier when the AGC is maximum An IF amplifier when the AGC is minimum an audio amplifier when the carrier is absent RF interference when the signal is weak An IF amplifier when the AGC is maximum An IF amplifier when the AGC is minimum an audio amplifier when the carrier is absent RF interference when the signal is weak ANSWER DOWNLOAD EXAMIANS APP
Radio Receivers Show which of the following statements about the amplitude limiter is untrue: When the input increases past the threshold of the limiting, the gain decreases to keep the output constant. Leak-type bias must be used The circuit is always biased in class C, by virtue of the leak-type bias. The output must be tuned When the input increases past the threshold of the limiting, the gain decreases to keep the output constant. Leak-type bias must be used The circuit is always biased in class C, by virtue of the leak-type bias. The output must be tuned ANSWER DOWNLOAD EXAMIANS APP
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