Indicate which of the following circuits could not demodulate SSB: Phase discriminator Balance modulator Product modulator BFO 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. The output must be tuned Leak-type bias must be used The circuit is always biased in class C, by virtue of the leak-type bias. TRUE ANSWER : ? YOUR ANSWER : ?
To prevent overloading of the IF amplifier in a receiver, one should use Squelch Variable selectivity Double conversion Variable sensitivity TRUE ANSWER : ? YOUR ANSWER : ?
If the intermediate frequency is very high (indicate false statement) Image frequency rejection is very good The local oscillator need not be extremely stable Tracking will be improved The selectivity will be poor 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 900 kHz 1650 kHz 2100 kHz 750 kHz TRUE ANSWER : ? YOUR ANSWER : ?
Indicate which of the following statements about the advantages of the phase discriminator over the slope detector is false: Greater limiting Fewer tuned circuits Much easier alignment Better linearity TRUE ANSWER : ? YOUR ANSWER : ?
The typical squelch circuit cuts off an audio amplifier when the carrier is absent RF interference when the signal is weak An IF amplifier when the AGC is minimum An IF amplifier when the AGC is maximum TRUE ANSWER : ? YOUR ANSWER : ?
In a ratio detector the linearity is worse than in phase discriminator the output is twice that obtainable from a similar phase discriminator the circuit is the same as in a discriminator, except that the diodes are reversed stabilization against signal strength variations is provided TRUE ANSWER : ? YOUR ANSWER : ?
A low ratio of the ac to the dc load impedance of a diode detector results in Poor AGC operation Diagonal clipping Negative-peak clipping Poor AF response 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 permit easier tracking To allow adequate frequency coverage without switching To help the image frequency rejection TRUE ANSWER : ? YOUR ANSWER : ?