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 decades Reduce the number of crystals required Reduce the spurious frequency problem TRUE ANSWER : ? YOUR ANSWER : ?
Indicate which of the following statements about the advantages of the phase discriminator over the slope detector is false: Better linearity Fewer tuned circuits Greater limiting Much easier alignment TRUE ANSWER : ? YOUR ANSWER : ?
Indicate which of the following circuits could not demodulate SSB: BFO Phase discriminator Balance modulator Product modulator TRUE ANSWER : ? YOUR ANSWER : ?
Indicate the false statement. Noting that no carrier is transmitter with J3E, we see that Production of AGC is a rather complicated process The receiver cannot use a phase comparator for AFC The transmission is not compatible with A3E Adjacent-channel rejection is more difficult TRUE ANSWER : ? YOUR ANSWER : ?
Indicate the false statement in connection with communications receivers. Double conversion is used to improve image rejection The noise limiter cuts off the receiver’s output during a noise pulse. Variable sensitivity is used to eliminate selective fading A product demodulator could be used for the reception of Morse code. TRUE ANSWER : ? YOUR ANSWER : ?
The image frequency of a superheterodyne receiver Is created within the receiver itself Is due to insufficient adjacent channel rejection Is not rejected be the IF tuned circuits Is independent of the frequency to which the receiver is tuned TRUE ANSWER : ? YOUR ANSWER : ?
The local oscillator of a broadcast receiver is tuned to a frequency higher than the incoming frequency To help the image frequency rejection To allow adequate frequency coverage without switching Because otherwise an intermediate frequency could not be produced To permit easier tracking TRUE ANSWER : ? YOUR ANSWER : ?
If a FET is used as the first AF amplifier in a transistor receiver, this will have the effect of Reducing the effect of negative-peak clipping Improving the effectiveness of the AGC Improving the selectivity of the receiver Reducing the effect of noise at low modulation depths TRUE ANSWER : ? YOUR ANSWER : ?
Three-point tracking is achieved with Double conversion Variable selectivity The padder capacitor Double spotting TRUE ANSWER : ? YOUR ANSWER : ?
When a receiver has good blocking performance, this means that It does not suffer from double-spotting Its detector suffers from burnout It is unaffected by AGC derived from nearby transmissions Its image frequency rejection is poor TRUE ANSWER : ? YOUR ANSWER : ?