Ramsey Electronics FM10C Manual page 12

1. Orient the board in the same direction as the parts layout diagram.
2. Install the 18 pin IC socket. If the socket has a notch in one end,
install it in the same position as shown on the Parts Layout Diagram to
prevent confusion later.
Audio Section
3. Install L2, a 2.2uH inductor (red-red-gold). Inductors have no polar-
ity so they may be installed in either direction.
4. Install L1, another 2.2uH inductor (red-red-gold).
5. Install C1, a 100pF ceramic capacitor (Marked 101). Ceramic ca-
pacitors are just like inductors they have no polarity so they may be in-
stalled in either direction.
6. Install C2, another 100pF ceramic capacitor (marked 101).
7. Install R1, a 13K ohm resistor (brown-orange-orange). Resistors are
similar to inductors they have no polarity so they may be installed in ei-
ther direction.
8. Install R2, another 13K ohm resistor (brown-orange-orange).
9. Install R3, a 1K ohm trimmer potentiometer. The top is orange and
marked 102. This pot is used to adjust the audio level to the right chan-
nel of the modulator IC. Seat it flat before soldering.
10. Install R4, another 1K ohm trimmer potentiometer. (marked 102).
This pot is used to adjust the audio level to the left channel of the modu-
lator IC.
11. Install C5, a .0047uF ceramic capacitor (marked 472).
12. Install C6, another .0047uF ceramic capacitor (marked 472).
13. Install R5 and R6, a 15K ohm resistor (brown-green-orange). These
resistors set the pre-emphasis characteristics for the FM10C at 75 uS for
use in the USA. Pre-emphasis is a technique used in FM transmitters to
increase the high frequency signal to noise ratio. For use in Europe and
other countries using 50 uS pre-emphasis use 10K resistors (brown-
black-orange).
Now we'll install some electrolytic caps. Electrolytic capacitors have a
right and wrong way to be installed. Usually, these capacitors have a
wide stripe which indicates their polarity. Most of the time this stripe indi-
cates the negative lead. This can be verified by looking for the (-) sign in
the stripe. On rare occasions this stripe with have a (+) sign indicating a
positive polarity. The PC board or Parts Layout Diagram will show the
positive side of the capacitor's installation hole. Be sure to place the
FM10A 12