WASTE WATER ENGINEERING QUIZ

The image frequency of a superheterodyne receiver

Is due to insufficient adjacent channel rejection

Is independent of the frequency to which the receiver is tuned

Is created within the receiver itself

Is not rejected be the IF tuned circuits

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

Improving the effectiveness of the AGC

Improving the selectivity of the receiver

Reducing the effect of negative-peak clipping

Reducing the effect of noise at low modulation depths

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Indicate the false statement. Noting that no carrier is transmitter with J3E, we see that

The transmission is not compatible with A3E

The receiver cannot use a phase comparator for AFC

Adjacent-channel rejection is more difficult

Production of AGC is a rather complicated process

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Indicate the false statement in connection with communications receivers.

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.

Variable sensitivity is used to eliminate selective fading

Double conversion is used to improve image rejection

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When a receiver has good blocking performance, this means that

Its detector suffers from burnout

It is unaffected by AGC derived from nearby transmissions

It does not suffer from double-spotting

Its image frequency rejection is poor

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

Permit better adjacent-channel rejection

Improve the rejection of the image frequency

Provide improved tracking

Increase the tuning range of the receiver

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To prevent overloading of the IF amplifier in a receiver, one should use

Variable sensitivity

Double conversion

Squelch

Variable selectivity

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A superheterodyne receiver with an IF of 450 kHz is tuned to a signal at 1200 kHz. The image frequency is

900 kHz

750 kHz

1650 kHz

2100 kHz

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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

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An AM receiver uses a diode detector for demodulation. This enables it satisfactorily to receive

Single-sideband, suppressed-carrier

Single-sideband, full-carrier

Single-sideband, reduced-carrier

ISB

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