are marked by polarity and must be installed in the proper direction. You’ll see that one side of the capacitor has a black band and is marked with a
12. Install C11, a
13. Install C2, 36pF ceramic disc capacitor (marked 36 or 36K). It goes across pins 6 and 7 of the SA602 IC. This capacitor is the first step in setting up the resonant frequency of the SA602’s internal oscillator, using the resonant LC circuit to be created along with C1, C3 and L1.
14. Install C1, 36pF disc capacitor (marked 36 or 36K).
15. Install C3, .01µF disc capacitor (marked 103 or .01 or 10nF).
16. Before installing L2 (marked
17. Install L2, shielded coil.
18. Install C4, a 15pF ceramic disc capacitor. C4 adds variable capacitance of the varactor tuning network to the oscillator circuit already formed by L2, C1, C2 and the SA602.
19. Install D1, the 1N4002 diode, making sure that the cathode or banded end is oriented towards the back of the PC board. This diode performs the function of a varactor diode. A varactor diode acts like a variable capacitor whose capacitance is controlled by the the voltage across it. There is nothing fancy about the varactor diodes, so we are using a common rectifier.
20. Install R5, 10k ohms
21. Install R2, 10k potentiometer tuning control.
22. Install R3, 10k potentiometer volume control. This control varies the level of audio from pin 4 of the SA602 to the LM386 audio amplifier.
23. Using a scrap piece of wire, snipped from an installed component, install
OPTION: with
24. Install S1, the power switch.