Page 152 - Build Your Own Transistor Radios a Hobbyists Guide to High-Performance and Low-Powered Radio Circuits

• T3 IF transformer: 42IF103, use low side tap on primary winding

• T4 audio driver transformer: 10 k

primary, 10 k

secondary; use the CT in the secondary for 2.5 k

or 10 k

primary, 2 k

secondary
• TS audio output transformer: 500

primary, 8

secondary

• DI, 02: 1N914
• D3: 1N270 or IN34
• QI, Q2: 2N3904
• vel: two gang-variable capacitor 140 pF and 60 pF

• LI antenna coil: 600 ~H to 680 ~H primary, 10 to 20 turns for secondary
winding
• L2: 4.7-mH induetor
Figure 10-4 presents the schematic diagram of the two-transistor two-stage reflex

superheterodyne radio. As seen in this diagram, a 9-volt battery will be used as the
power supply, and the radio will drain around 10 mA to 20 mA for driving a
loudspeaker.