Detailed Signal Path

1. Reception:
The antenna receives the AM signal, which is tuned by the LC circuit.

2. Detection:
The diode (1N4148) detects the amplitude variations in the signal, which correspond to the audio information.

3. First Stage Amplification (BC547):
The detected RF signal is fed into the base of the BC547.
The BC547 amplifies this signal, and the amplified RF signal appears at the collector.

4. Second Stage Amplification (BC557):
The amplified RF signal from the BC547’s collector is fed into the base of the BC557.
The BC557 amplifies the audio component of the signal.
The amplified audio signal is then passed through the coupling capacitor to the external amplifier.

5. Output:
The external amplifier further boosts the audio signal to drive a speaker, producing the sound corresponding to the received radio station.