RADIO RECEIVERS QUIZ

In a broadcast superheterodyne receiver, the

Local oscillator frequency is normally double the IF

RF amplifier normally works at 455 kHz above the carrier frequency

Local oscillator operates below the signal frequency

Mixer input must be tuned to the signal frequency

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

The circuit is always biased in class C, by virtue of the leak-type bias.

Leak-type bias must be used

TRUE ANSWER : ?
YOUR ANSWER : ?

The local oscillator of a broadcast receiver is tuned to a frequency higher than the incoming frequency

To permit easier tracking

To help the image frequency rejection

To allow adequate frequency coverage without switching

Because otherwise an intermediate frequency could not be produced

TRUE ANSWER : ?
YOUR ANSWER : ?

When a receiver has good blocking performance, this means that

It is unaffected by AGC derived from nearby transmissions

Its image frequency rejection is poor

It does not suffer from double-spotting

Its detector suffers from burnout

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

900 kHz

2100 kHz

1650 kHz

TRUE ANSWER : ?
YOUR ANSWER : ?

The controlled oscillator synthesizer is sometimes preferred over the direct one because

It does not require crystal oscillator

It is relatively free of spurious frequency

It is a simpler piece of equipment

Its frequency stability is better

TRUE ANSWER : ?
YOUR ANSWER : ?

Indicate the false statement in connection with communications receivers.

Double conversion is used to improve image rejection

Variable sensitivity is used to eliminate selective fading

The noise limiter cuts off the receiver’s output during a noise pulse.

A product demodulator could be used for the reception of Morse code.

TRUE ANSWER : ?
YOUR ANSWER : ?

Indicate which of the following circuits could not demodulate SSB:

Phase discriminator

BFO

Product modulator

Balance modulator

TRUE ANSWER : ?
YOUR ANSWER : ?

One of the main functions of the RF amplifier in a superheterodyne receiver is to

Improve the rejection of the image frequency

Provide improved tracking

Increase the tuning range of the receiver

Permit better adjacent-channel rejection

TRUE ANSWER : ?
YOUR ANSWER : ?

If a FET is used as the first AF amplifier in a transistor receiver, this will have the effect of

Improving the selectivity of the receiver

Improving the effectiveness of the AGC

Reducing the effect of noise at low modulation depths

Reducing the effect of negative-peak clipping

TRUE ANSWER : ?
YOUR ANSWER : ?

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