- This is the circuit diagram of the simplest single chip AM radio
- The circuit is designed around the IC ZN414Z which is a ten transistor tuned radio frequency receiver .The IC has only three leads and is available in the TO92 package.
- All necessary circuits required for an AM receiver (RF amplifier, detector and AGC are incorporated inside the IC).
- Capacitor C4 decouples DC from the output of the IC and C1 bye-passes the noise.
- Transistor Q1 and associated components forms a classic driver stage for the headphone.
- Head phone is connected across the resistor R5 and R4 gives necessary biasing for the transistor Q1.
NOTES:
- Assemble the circuit on a good quality PCB.
- The circuit can be powered from a 1.5V cell.
- Do not give more than 1.8V to the circuit as it will destroy the IC.
- For L1 make 80 turns of 0.3mm enameled copper wire on a 5cm long ferrite rod.
- K1 can be a high impedance crystal earpiece.