Simplest FM Radio, catches 16MHz(+- few MHz) . The AC source is an antenna. WAIT FOR 1 MINTUE FOR THE CIRCUIT TO STABILIZE!!!!!!
You shall change the frequency very fast (like to 20mhz) to notice change. Otherwise FM radio wont give you any signal wh!!en there is no signal.
The peak after it would be higher, means more current for a second. Means the speaker would respond as a click or a more volume noise
It catches a particular frequency and then increases it throw AND Gate, making a band pass filter complete.
Then the signal passes throw two paths->
1. Directly throw a filter to clean the signal.
2. Through a phase shifter which shifts the phase of the wave by 90○.
These two signals are then passed through another AND Gate and then through a low pass filter to complete the demodulator. This is based on the quadrature circuit which works by mixing phase shifted and normal waves together and deriving the change in frequency as signal.
The yellow line graph changes its peaks as the frequency changes for a while before stabilizing. These changes in peaks can be caught by a headphone as clicks.
