FM100B
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19
A. DISPLAY BOARD
We will begin with the display board oriented in the direction shown. Be sure
not to confuse the sides of the board where the parts go. On the board you will
see the side marked FRONT which is where most parts are mounted. We will
begin with lower parts and work up to the higher ones. Don’t use sockets for
these parts since they need to fit between the front panel and the PC board.
Note that only in section D (the audio LPF) of this kit will all four color bands
be listed for the standard 5% resistors. Do not use any of the five color band
resistors unless specifically instructed. These are the tighter tolerance parts
that are needed only in certain sections.
1A. Install R98, a 22K ohm resistor (red-red-orange). This resistor sets the
current to each of the display segments and LEDs driven by U11. Lowering
the value of this resistor increases the brightness of the display (the display
will draw more current however). This resistor was selected for best
brightness/current trade-off.
2A. Install C84, a 0.01 uF ceramic capacitor (marked 103). This capacitor
prevents the current set pin from doing odd things like oscillating by itself.
3A. Install C86, another 0.01 uF ceramic capacitor (marked 103).
4A. Install R96, a 1K ohm resistor (brown-black-red)
5A. Install R97, another 1K ohm resistor (brown-black-red).
6A. Install U9, one of the LM3915 Semi-log bargraph driver ICs. Make
absolutely sure before soldering that you have installed all 18 pins into the
appropriate holes. Verify that the notch or dot indicating pin one is facing
the same direction shown in the Parts Layout Diagram. Solder all 18 pins
and then check for any possible solder bridges when you’re done.
7A. Install U10, the other LM3915 Semi-log bargraph driver. Again make
sure all 18 pins are through the board and that the IC is in the correct
orientation.
8A. Install U11, the MM5451 40 pin IC. Again make sure the notch is in the
same direction as shown on the Display Board Parts Layout Diagram and
that all 40 pins are through the board before soldering. This IC drives all
the individual segments of the display without multiplexing it (which would
add noise to the system!).
9A. Install DISP3, one of the ten segment bargraph displays. You will
notice a small divot or notch on one corner of the bargraph indicating
where pin 1 is. This will be installed in the same orientation as the notch in
the parts layout diagram. Solder all 20 pins.
Содержание FM100B
Страница 17: ...FM100B 17 SECTION LAYOUT ON MAIN BOARD B C D1 D2 H E G F I ...
Страница 27: ...FM100B 27 DISPLAY SCHEMATIC ...
Страница 35: ...FM100B 35 MAIN BOARD PARTS LAYOUT ...
Страница 44: ...FM100B 44 REAR PANEL WIRING PICTURES AC Input and RF Output Fuse Wiring Close up ...
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