A superheterodyne receiver is tuned to a station at 20 MHz. The local oscillator frequency is 80 MHz and the IF is 100 MHz.
(a) What is the image frequency?
(b) If the LO has appreciable second-harmonic content, what two additional frequencies are received?
(c) If the RF amplifier contains a single-tuned parallel resonant circuit with Q = 50 tuned to 20 MHz, what will be the image attenuation in dB?
