Page 126 - Build Your Own Transistor Radios a Hobbyists Guide to High-Performance and Low-Powered Radio Circuits

An audio driver stage amplifies the demodulated AM signal with sufficient current

drive to a push-pull audio amplifier for listening via a loudspeaker or low-impedance
earphone.
Parts List

• Cl, C6, C8: 0.15 lJF
• C2, CS, C12, C1S: 33 pF, 16 volts
• C3, C4, C7, C9, C18, C19, C20: 0.01 pF

• Cl0, Cll, C17: 1 pF, 35 volts
• C13, C14, C16: 220 IJF, 16 volts
• Rl, R13: 2,200

• R2, R4, R6: 1,000

• R3, R10: 4,700

• RS, R12: 10 k

• R7, R8: 20 k

• R9: 100 k

• Rl1: 470

• R14: 3.0

• 01, 02, 03, 04, 05: lN914
• 06: lN270 or lN34
• Ql to Q8: 2N3904
• Ll antenna coil: 600 pH to 680 pH with tap or secondary winding

• VCl variable capacitor: 140 pF and 60 pF
• Tl oscillator coil: 42IF100
• T2 IF transformer: 42IF10l

• T3 IF transformer: 42IF102
• T4 IF transformer: 42IF103
• Ts audio transformer: primary 1.5 k

, seconda ry 600

CT

• T6 audio transformer: primary 48