5. Explain how image-frequency signals are received in a superheterodyne receiver. How can these signals be rejected.
11. What is AGC? Why is it required in a practical receiver?
28. A tuned circuit has a Q of 60 at 5MHz. Find it?s bandwidth at 5 MHz and 20 MHz.
29. A superheterodyne receiver is tuned to a frequency of 5 MHz when the local oscillator frequency is 6.65 MHz.
(a) What is the IF?
(b) Which type of injection is in use?
30. A superheterodyne receiver has an IF of 9 MHz and tunes the frequency range from 50 to 60 MHz. The mixer uses low side injection of the local oscillator signal. Calculate the range of the local oscillator frequencies.
32. One receiver has a sensitivity of 1?V and another has a sensitivity of 10 dBf under the same measurement conditions. Both receivers have an input impedance of 50 O. Which receiver is more sensitive?
36. An AM broadcast receiver with high side injection and an IF of 455kHz is tuned to a station at 910kHz.
(a) What is the local oscillator frequency?
(b) What is the image frequency?