- A. Local oscillator operates below the signal frequency
- B. Mixer input must be tuned to the signal frequency
- C. Local oscillator frequency is normally double the IF
- D. RF amplifier normally works at 455 kHz above the carrier frequency
Radio Receivers
-
In a broadcast superheterodyne receiver, the_____.
-
A low ratio of the ac to the dc load impedance of a diode detector results in_____.
- A. Diagonal clipping
- B. Poor AGC operation
- C. Negative-peak clipping
- D. Poor AF response
-
To prevent overloading of the IF amplifier in a receiver, one should use_____.
- A. Squelch
- B. Variable sensitivity
- C. Variable selectivity
- D. Double conversion
-
The controlled oscillator synthesizer is sometimes preferred over the direct one because_____.
- A. It is a simpler piece of equipment
- B. Its frequency stability is better
- C. It does not require crystal oscillator
- D. It is relatively free of spurious frequency
-
An AM receiver uses a diode detector for demodulation. This enables it satisfactorily to receive_____.
- A. Single-sideband, suppressed-carrier
- B. Single-sideband, reduced-carrier
- C. ISB
- D. Single-sideband, full-carrier
-
The image frequency of a superheterodyne receiver_____.
- A. Is created within the receiver itself
- B. Is due to insufficient adjacent channel rejection
- C. Is not rejected be the IF tuned circuits
- D. Is independent of the frequency to which the receiver is tuned
-
Indicate which of the following circuits could not demodulate SSB:
- A. Balance modulator
- B. Product modulator
- C. BFO
- D. Phase discriminator
-
If a FET is used as the first AF amplifier in a transistor receiver, this will have the effect of_____.
- A. Improving the effectiveness of the AGC
- B. Reducing the effect of negative-peak clipping
- C. Reducing the effect of noise at low modulation depths
- D. Improving the selectivity of the receiver
-
A superheterodyne receiver with an IF of 450 kHz is tuned to a signal at 1200 kHz. The image frequency is_____.
- A. 750 kHz
- B. 900 kHz
- C. 1650 kHz
- D. 2100 kHz
-
In a ratio detector_____.
- A. the linearity is worse than in phase discriminator
- B. stabilization against signal strength variations is provided
- C. the output is twice that obtainable from a similar phase discriminator
- D. the circuit is the same as in a discriminator, except that the diodes are reversed