Page 140 - Build Your Own Transistor Radios a Hobbyists Guide to High-Performance and Low-Powered Radio Circuits

~ ~ I'
RF Antenna Filter Mixer IF Filter 1 IF Amplifier IF Filter 2 IF Amplifier
VC1_ RFIL1 Q3 T2_ IF Q4 T3_ IF Q5

+~'RF

210 pr
Oet ~ IF Filter 3
03 T4- IF

Oscillator
Audio Amplifier
Local Oscillator Signal
VC1 0"
Q6
T1/Q1_ Q2
+~,o"

/~ 270pf

FIGURE 9-3 A low-power superheterodyne radio with a twin-gang

variable capacitor.
Parts List

• Cl, C2, C3, C7, C8, C9, Cl0, C11 , C12, C17, C18, C19, C20: 0.01 ~F
• C4, CS, Cls: 33 ~F, 16 volts
• C6: 0.15 ~F
• C13: 0.0022 ~F

• C14: 1 ~F, 35 volts or 33 ~F, 16 volts
• C16: 330 pF
• RI, R2: 22 k
n

• R3, R4, R12: 56 k
n

• Rs, R6, R7: 12 k
n

• R8, RIO, R13, R14, Rls: 100 k
n

• R9: 1.1 M
n

• R11 : 1 M
n
or 1.1 M
n

• 01, 02: 1N914
• 03: lN34 or 1N270
• QI, Q2, Q3, Q4, Qs: MPSH 10