I have to build a project with a AM transmitter and receiver. The idea is that I will speak something which will be transmitted and received to the receiver. The Transmitter and the receiver assembly will be located very close (within couple of feet). My question is that for the receiver circuit, do i still need a tuner even though it is receiving only one signal from the transmitter?
My question is that for the receiver circuit, do i still need a tuner even though it is receiving only one signal from the transmitter?
Radio receivers use "tuning" so they can discriminate against those radio frequencies that they DO NOT want to receive thus, only allowing through the frequency of carrier wave that they DO want to receive.
You also need a demodulator to convert the modulated carrier back to audio/speech.
You can use dipoles, but at 1MHz for 1/2 wavelength you need 1/2 of 300 meters.
I suggest you use resonant flat (pancake coil) inductors with air-capacitors. For Q of 100 at 1MHz (giving you +-5KHz bandwidth -3dB), with 1 ohm loss assumed, the ZL and ZC is J100. That requires 16 uH inductor, loop or pancake style. Cap is ---- 1uF at 1MHz is -j0.16 ohm; you need 1uF/600 = 1,600pF. Either the Tx or Rx antenna needs some mica trimmers or air-gap trimming.