Electronic Communication Systems 2nd Edition by Roy Blake

Exercise 52

An AM broadcast receiver tunes from 530 to 1700 kHz. The IF is 455 kHz and the local oscillator uses high-side injection. The local oscillator uses a variable capacitor with a maximum value of 365 pF. Calculate:
(a) the range of frequencies that must be generated by the local oscillator
(b) the value of inductor needed so that the local oscillator will tune the receiver to the lowest frequency on the band when the capacitor is at maximum
(c) the required minimum value for the variable capacitor so that the receiver will be tuned to the highest frequency on the band when the capacitor is set at minimum