Radio Receivers The frequency generated by each decade in a direct frequency synthesizer is much higher than the frequency shown; this is done to Reduce the spurious frequency problem Reduce the number of crystals required Increase the frequency stability of the synthesizer Reduce the number of decades Reduce the spurious frequency problem Reduce the number of crystals required Increase the frequency stability of the synthesizer Reduce the number of decades ANSWER DOWNLOAD EXAMIANS APP
Radio Receivers If the intermediate frequency is very high (indicate false statement) The local oscillator need not be extremely stable The selectivity will be poor Tracking will be improved Image frequency rejection is very good The local oscillator need not be extremely stable The selectivity will be poor Tracking will be improved Image frequency rejection is very good ANSWER DOWNLOAD EXAMIANS APP
Radio Receivers Indicate the false statement. The superheterodyne receiver replaced the TRF receiver because the latter suffered from Gain variation over the frequency coverage range Insufficient gain and sensitivity Inadequate selectivity at high frequencies Instability Gain variation over the frequency coverage range Insufficient gain and sensitivity Inadequate selectivity at high frequencies Instability ANSWER DOWNLOAD EXAMIANS APP
Radio Receivers Show which of the following statements about the amplitude limiter is untrue: Leak-type bias must be used The output must be tuned The circuit is always biased in class C, by virtue of the leak-type bias. 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 output must be tuned The circuit is always biased in class C, by virtue of the leak-type bias. When the input increases past the threshold of the limiting, the gain decreases to keep the output constant. ANSWER DOWNLOAD EXAMIANS APP
Radio Receivers Indicate the false statement in connection with communications receivers. The noise limiter cuts off the receiver’s output during a noise pulse. Variable sensitivity is used to eliminate selective fading Double conversion is used to improve image rejection A product demodulator could be used for the reception of Morse code. The noise limiter cuts off the receiver’s output during a noise pulse. Variable sensitivity is used to eliminate selective fading Double conversion is used to improve image rejection A product demodulator could be used for the reception of Morse code. 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 Mixer input must be tuned to the signal frequency Local oscillator operates below the signal frequency RF amplifier normally works at 455 kHz above the carrier frequency Local oscillator frequency is normally double the IF Mixer input must be tuned to the signal frequency Local oscillator operates below the signal frequency ANSWER DOWNLOAD EXAMIANS APP
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