Ramsey Electronics FM25B Assembly And Instruction Manual page 14

socket check to be sure that none of the pins are bent under or outside of
the socket. When you're sure the pins are where they belong, press it
down so that it is seated flat within the socket.
4. Install U1, the LM358 dual op-amp. Again, orient the dotted or
notched end as shown on the silkscreen and be sure to solder all 8 pins.
5. Install S4, the DPDT push-button switch. You'll want this part to be
seated correctly so that the power button moves freely when in the case.
Set it flush to the PC board before soldering all six pins.
6. Install J2, the 2.1mm DC power jack. You can gently bend the leads
to keep this part from falling out of the board when you flip the board over
to solder it.
7. Install J3, the PC mount "F" connector. This is another part that you'll
want to seat correctly before soldering or it won't fit through the back
panel properly. Be sure to solder the ground connections well. They may
require more heat but when working with RF, a good ground is essential.
Progress Note: The preceding steps have secured a sufficient number of com-
ponents to your PC board to make general orientation around the board much
clearer for installing additional parts.
Most of the resistors will be installed in a stand up fashion. That is, one lead
will go straight into the board while the other is bent around to go back down
into the other hole. The straight lead goes into the hole with the circle around
it.
8. Install D17, the 1N4000 series diode (4001 - 4007)(black with white
band). The body of the part should be placed in the hole with the circle
around it and the band or stripe should be up when oriented properly.
9. Install L3, 1µH axial inductor (looks like a fat resistor with brown-
black-gold bands).
10. Install C36, .001 µF disc capacitor (marked .001, 102 or 1nF).
11. Install L5, the other 1µH axial inductor (looks like a fat resistor with
brown-black-gold bands).
12. Install C35, .001 µF disc capacitor (marked .001, 102 or 1nF).
13. Install R28, one of the 10k ohm trimmer potentiometers (marked 103).
There are two of these parts; don't confuse either one with the 1k trimmer
marked 102. Seat it flat before soldering.
14. Install the other 10k trimmer pot, R27 (marked 103).
15. Install J5, one of the stereo jacks. Proper positioning of this part will
help you later with case-up so be sure it's where you want it before solder-
ing.
FM25B • 14