Ramsey Electronics FX Series Manual page 94

make mistakes: skipping connections, causing solder bridges, etc. Some
builders may prefer to push ahead and do all of the repetitive soldering as a
single operation, while others do better work with frequent breaks in the
phases that involve repetition of steps. The suggested order of assembly is
for the benefit of the latter group. If you wish to proceed differently, feel free
to do so. Just be sure to check off the respective assembly steps as you
finish or review your work.
G1a. Insert the 28-pin DIP socket for U6 into its PC board position and
slightly bend the 4 outermost pins to hold it in place.
G1b. Examine the solder side and verify that ALL 28 pins are extended
into their respective holes. Press the socket squarely onto the board,
solder the 4 corner pins, check for proper seating, then solder remaining
pins.
G2. Install U6, MC145152, check that all pins are fully seated.
G3. Install oscillator crystal Y2, 10.240 MHz. Be sure it is firmly seated
on the board, then solder.
G4. Install C87, 39 pf.
G5. Install C80, 39 pf.
G6. Install R38, 10K (brown-black-orange).
G7. Identify C81, a 35 pf. trimmer capacitor. (C81 has a black body and
orange top.) Press it in place flat on the PC board.
G8. Solder C81's two connections.
G9. Identify and install U5, the LM358 dual op amp IC. Be certain to
orient the notched end as pictured on the PC board.
OBSERVE CORRECT POLARITY FOR THESE CAPACITORS:
G10. Install C70, 2.2 uf. electrolytic.
G11. Install C67, 2.2 uf. electrolytic.
G12. Install C96, 4.7 or 10 uf. electrolytic.
G13. Install C90, 2.2 uf. electrolytic.
G14. Install C92, 2.2 uf. electrolytic.
G15a. Insert U7, type 74HC283 IC with its notched end correctly
oriented. Solder the 4 outermost pins.
G16a. Insert and solder U8 as in step G15a.