Yes, the carrier frequency of any ONE AM station is constant - as distinct from FM where it varies.kinjalgp said:Oops sorry! But I have never seen a varicap in AM receiver.
Frequency in AM is constant and therefore if a varicap diode is used in AM receiver, it will just act as a constant value capacitor for a chosen carrier which means there is no point in using a varicap. A constant value capacitor can also be used in its place.
Whereas in FM, frequency is releted to modulating signal and so any change in frequncy will affect the capacitance of varicap which can be used to demodulate the FM signal.
Well, this is what I am thinking, but there may be AM circuits which uses this diode. IF anyone has one, I would like to see it.