Radio Receivers
In a ratio detector

stabilization against signal strength variations is provided
the linearity is worse than in phase discriminator
the circuit is the same as in a discriminator, except that the diodes are reversed
the output is twice that obtainable from a similar phase discriminator

ANSWER DOWNLOAD EXAMIANS APP

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

Variable sensitivity is used to eliminate selective fading
Double conversion is used to improve image rejection
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.

ANSWER DOWNLOAD EXAMIANS APP

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

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

ANSWER DOWNLOAD EXAMIANS APP

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

Reducing the effect of noise at low modulation depths
Reducing the effect of negative-peak clipping
Improving the selectivity of the receiver
Improving the effectiveness of the AGC

ANSWER DOWNLOAD EXAMIANS APP