Ramsey Electronics FX Series Manual page 83

Stage E: BASIC VCO ASSEMBLY
In this Stage, we will assemble the basic VCO (Voltage Controlled Oscillator)
circuit. Understanding the function of this stage is especially important for
knowing how the FX transceiver works.
E1. Select and install shielded coil L7 (orange bottom). It fits in two
different ways, and either way will work. Be VERY sure BEFORE
soldering that this coil is seated snugly on the PC board.
E2. Install C43, 15 pf (marked 15).
E3. Install C54, 22 pf disc capacitor (marked 22).
E4. Install C51, 10 pf disc capacitor (marked 10).
E5. Install R30, 51 ohm (green-brown-black).
E6. Install R22, 10K ohm (brown-black-orange).
E7. Install R18, 270 ohm (red-violet-brown).
E8. Install R66, 47K ohm (yellow-violet-orange).
E9. Install Q7, NPN type 2SC2498. Before soldering be sure to identify
Q7 correctly and that it is inserted with its flat side as shown in the parts
diagram.
E10. Install varactor diode D23, type BB505. It has an orange body with
a black band. Be certain of correct diode identification and orientation of
cathode (black band) end.
E11. Similarly, install D3, also type BB505. Watch that polarity!
E12. Install C36, .01 uf disc capacitor (marked .01 or 103).
E13a. Install C40, 47 uf, electrolytic. Be sure to orient polarity as shown.
E13b. Install R19, 4.7K ohm (yellow-violet-red).
E14. Install C39, 100 pf disc capacitor (marked 100 or 101).
E15. Install D1, type 1N914 or 1N4148.
E16. Install R15 and R115, both upright, 1K ohm (brown-black-red).
E17. Install C99, .01 uf disc capacitor (marked .01 or 103).
E18. Install R25, upright, 47K ohm (yellow-violet-orange).
E19. Install Q4, NPN type 2N3904. Be sure to orient flat side as
illustrated.