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

Squelch
Variable sensitivity
Variable selectivity
Double conversion

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Radio Receivers
In a broadcast superheterodyne receiver, the

RF amplifier normally works at 455 kHz above the carrier frequency
Local oscillator frequency is normally double the IF
Mixer input must be tuned to the signal frequency
Local oscillator operates below the signal frequency

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Radio Receivers
Show which of the following statements about the amplitude limiter is untrue:

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
When the input increases past the threshold of the limiting, the gain decreases to keep the output constant.

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Radio Receivers
Indicate the false statement in connection with communications receivers.

The noise limiter cuts off the receiver’s output during a noise pulse.
Variable sensitivity is used to eliminate selective fading
Double conversion is used to improve image rejection
A product demodulator could be used for the reception of Morse code.

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