Here is a circuit about TA7642 IC application in simple AM radio The TA7642 IC is similar to ZN414 IC. ZN414 IC was a very famous am radio IC among electronics enthusiasts few years ago but now it is no more available in the market because it has been discontinued several years ago and now TA7642 and MK484 ICs has taken.
Its place and the performace of these ICs are similar to ZN414
IC.The circuit mentioned here is a simple am receiver which can be built in a short time if all parts are available with you. The Coil L1 is equal to 55 turns of 0.315mm enamelled copper wire wound on 10mm x 100mm long ferrite rod. You can also experiment with any am radio coil you have in scrap.
you want further audio amplification to drive a speaker use other circuits of am receivers in the Radio & RF circuits section.