Heathkit IG-18 - Page 37

Connect the three yellow wires coming from lug
R10 of switch D as directed in the following
three steps:
The longest yellow wire to lug R7 of
switch C (S-1),
( ) The next longest yellow wire to lug R10 of
switch E (NS). Route this wire under the
white wire.
The remaining yellow wire to hole H on the
generator circuit board (S-1).
Connect the brown wire coming from lug R5
of switch D to lug Rll of switch C (S-1),
Connect the brown wire coming from lug
R5 of switch E to lug R8 of switch D (S-3),
Pass the stripped end of the brown wire com-
ing from lug 8 of switch E through lug 6
(S-2) to lug 3 (S-1) of control F,
( ) Connect an 82 kQ (gray-red-orange) re-
sistor from lug 1 (S-2) to lug 2 (8-1) of
control F.
( ) Connect an 82 kQ (gray-red-orange) re-
sistor from lug 4 (NS) to lug 5 (8-1) of
control F.
( ) Connect a 27 kQ (red-violet-orange) resis-
tor from lug 1 (NS) to lug 2 (NS) of termi-
nal strip Z.
( )
Prepare the following lengths of hookup wire:
3-1/2" yellow
17" black
17" brown
( ). Connect a 3-1/2" yellow wire from lug 4
of
control F (S-2) to lug RIO of switch E
(S-2). Be sure to solder both lugs at RIO.
( ) Twist the 17" black and the 17" brown wires
together to form a twisted pair.
( ) Pass one end of this twisted pair through the
opening at the rear of the chassis as shown.
This end will be connected later.
1"
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2"
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( ) At the other end of this twisted pair, connect
the brown wire to lug 1 (S-2) and the black
wire to lug 3 (NS) of terminal strip Z.
( )
Locate the neon lamp and insert it into the
pilot lamp lens,
Strip 3" of insulation from a piece of brown
hookup wire and cut it in half.
Place a 1-1/2" piece of insulation on each
of the pilot lamp leads. Then connect one
lead to lug 2 (S-2) and the other lead to lug
3
(S-2) of terminal strip Z,
Detail 17A
NOTE: Always mount electrolytic capacitors
so the positive (+) mark on the capacitor
matches the positive (+) mark on the circuit
board, See Detail 17 A. Bend the leads slightly
to hold the capacitors in place until they are
soldered.
( ) Mount the two 250 fJ. F electrolytic capaci-
tors on the generator circuit board as
shown.
Mount
the three 300 fJ. F electrolytic capaci-
tors on the power supply circuit board.
Solder all connections to the foil and cut off
the excess lead lengths.
NOTE: Both circuit boards are now complete,
however, you will notice four open holes in the
power supply circuit board. These holes are not
used.
3"
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4"
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5"
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6"
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