2N2222 Shortwave radio receiver circuit
This shortwave radio receiver circuit project is based on 2N2222 transistors and has an operating frequency range between 6 and 17 Mhz .
This 2N2222 Shortwave radio receiver circuit works with a short whip antenna and must be powered from an 9 volts DC powers supply.
All coils are designed using an inch diameter pvc pipe using 20 gauge insulated hookup wire , L1 require 6 turns and L2 require 14 turns.
You can add turns to or subtract turns from L(or change C2) to receive other frequencies.
R1 and R2 provide a large amount of negative bias at the emitter of Q1 to achieve smooth control.
Q2 and Q3 form an amplifier, which has sufficient output level to directly drive headphones or a small speaker, amplify the detected audio signal output from D1. R3can replaced with a 2k ohms potentiometer , if you want to use it as an volume control .
R4 and C4 form a lowpass filter that maintains circuit stability and improves the receiver's sound quality. D2, D3, and D4 implement a low-cost voltage regulator to keep the voltage supplying Q1 fairly constant, which minimizes drift.