One of the main functions of the RF amplifier in a superheterodyne receiver is to Permit better adjacent-channel rejection Increase the tuning range of the receiver Improve the rejection of the image frequency Provide improved tracking TRUE ANSWER : ? YOUR ANSWER : ?
A low ratio of the ac to the dc load impedance of a diode detector results in Poor AF response Diagonal clipping Poor AGC operation Negative-peak clipping TRUE ANSWER : ? YOUR ANSWER : ?
The controlled oscillator synthesizer is sometimes preferred over the direct one because It does not require crystal oscillator It is a simpler piece of equipment Its frequency stability is better It is relatively free of spurious frequency TRUE ANSWER : ? YOUR ANSWER : ?
A superheterodyne receiver with an IF of 450 kHz is tuned to a signal at 1200 kHz. The image frequency is 750 kHz 2100 kHz 1650 kHz 900 kHz TRUE ANSWER : ? YOUR ANSWER : ?
When a receiver has good blocking performance, this means that Its detector suffers from burnout It does not suffer from double-spotting Its image frequency rejection is poor It is unaffected by AGC derived from nearby transmissions 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 noise at low modulation depths Reducing the effect of negative-peak clipping Improving the selectivity of the receiver Improving the effectiveness of the AGC TRUE ANSWER : ? YOUR ANSWER : ?
The local oscillator of a broadcast receiver is tuned to a frequency higher than the incoming frequency Because otherwise an intermediate frequency could not be produced To allow adequate frequency coverage without switching To help the image frequency rejection To permit easier tracking TRUE ANSWER : ? YOUR ANSWER : ?
The frequency generated by each decade in a direct frequency synthesizer is much higher than the frequency shown; this is done to Reduce the number of crystals required Reduce the number of decades Reduce the spurious frequency problem Increase the frequency stability of the synthesizer TRUE ANSWER : ? YOUR ANSWER : ?
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 output must be tuned The circuit is always biased in class C, by virtue of the leak-type bias. 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 Greater limiting Much easier alignment Fewer tuned circuits TRUE ANSWER : ? YOUR ANSWER : ?