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

To help the image frequency rejection
To allow adequate frequency coverage without switching
To permit easier tracking
Because otherwise an intermediate frequency could not be produced

ANSWER DOWNLOAD EXAMIANS APP

Radio Receivers
In a radio receiver with simple AGC

An increase in signal strength produces more 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

ANSWER DOWNLOAD EXAMIANS APP

Radio Receivers
In a broadcast superheterodyne receiver, the

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

ANSWER DOWNLOAD EXAMIANS APP

Radio Receivers
In a ratio detector

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

ANSWER DOWNLOAD EXAMIANS APP