Radio Receivers
Indicate the false statement. The superheterodyne receiver replaced the TRF receiver because the latter suffered from

Inadequate selectivity at high frequencies
Insufficient gain and sensitivity
Instability
Gain variation over the frequency coverage range

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

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

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Radio Receivers
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.

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Radio Receivers
In a radio receiver with simple AGC

The audio stage gain is normally controlled by the AGC
The faster the AGC time constant the more accurate the output
The highest AGC voltage is produced
An increase in signal strength produces more AGC

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