Key Topic 45: IF Amplifiers

Question 1

3-45F1: What degree of selectivity is desirable in the IF circuitry of a wideband FM phone receiver?

A. 1 kHz.
B. 2.4 kHz.
C. 4.2 kHz.
D. 15 kHz.

Answer 1

D. 15 kHz.

Question 2

3-45F2: Which one of these filters can be used in micro-miniature electronic circuits?

A. High power transmitter cavity.
B. Receiver SAW IF filter.
C. Floppy disk controller.
D. Internet DSL to telephone line filter.

Answer 2

B. Receiver SAW IF filter.

Question 3

3-45F3: A receiver selectivity of 2.4 kHz in the IF circuitry is optimum for what type of signals?

A. CW.
B. Double-sideband AM voice.
C. SSB voice.
D. FSK RTTY.

Answer 3

C. SSB voice.

Question 4

3-45F4: A receiver selectivity of 10 kHz in the IF circuitry is optimum for what type of signals?

A. Double-sideband AM
B. SSB voice.
C. CW.
D. FSK RTTY

Answer 4

A. Double-sideband AM

Question 5

3-45F5: What is an undesirable effect of using too wide a filter bandwidth in the IF section of a receiver?

A. Output-offset overshoot.
B. Undesired signals will reach the audio stage.
C. Thermal-noise distortion.
D. Filter ringing.

Answer 5

B. Undesired signals will reach the audio stage.

Question 6

3-45F6: How should the filter bandwidth of a receiver IF section compare with the bandwidth of a received signal?

A. Slightly greater than the received-signal bandwidth.
B. Approximately half the received-signal bandwidth.
C. Approximately two times the received-signal bandwidth.
D. Approximately four times the received-signal bandwidth.

Answer 6

A. Slightly greater than the received-signal bandwidth.