Electronic Devices - Communications - Discussion

The value of intermediate frequency should be designed so that it should not lie within the range of mixer stage. Otherwise, there is the production of noise signal due to the interference of mixer frequency & intermediate frequency. Also, the intermediate frequency should not be too high. Otherwise, it will reduce the selectivity of the receiver because of increase in bandwidth. Considering all these factors 455 khz is the most suitable intermediate frequency value for an AM receiver.