We have a project to make and we were asked to make an AM radio broadcast receiver that is tuned only at a single frequency (702 kHz) but I don't know how to make one. The stores sell kit of a simple AM pocket radio receiver but all the radio stations are available there. How can you change the frequency in an AM radio receiver? A variable capacitor? If that is the case, what value of capacitance do I need in able to tune our AM radio receiver to 702 kHz? I'm from the Philippines and would there be any difference in the calculation of capacitance if you were in other countries? Thanks.