Elecraft KPA100 Manual - Manual (Page 33)

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Cut the two fan wires to a length of 2" (5 cm), measured from where
they exit the fan's frame. Remove 1/4" (6.4 mm) of insulation from each
wire, then twist together and lightly tin the strands.
Secure the fan to the rear panel using four 4-40 x 11/16" (17.5 mm)
flat head screws, four #4 split lock washers, and four 4-40 nuts.
Locate two DC input connector housings, one red and one black.
Hold the two connectors in the orientation shown in Detail B1 of Figure
24. Look closely at the sides of the connectors. Each has a small tongue
on the right side, and a groove on the left.
Slide the tongue on the right side of the red housing into the groove
on the left side of the black housing. Make sure the housings are mated
exactly as shown in Detail B1, with the black housing to the right and the
"hoods" at the front of the connectors facing up. Make sure the
interlocking tongue and groove are fully meshed.
Install right-angle PCB pins into the housings (Detail B2). The long
end of the pin should be inserted into the housing until it snaps into
position, and the short end must point down. When the pin is correctly
inserted, the distance from the back end of the housing to the bend in the
pin will be exactly 0.4" (10 mm).
Insert the paired housings through the rectangular rear-panel hole,
with the red housing aligned with the "+" label.
Use two E-shaped brackets to hold the housings in place, as shown
in Detail B3 (one from above, one from below). Secure the brackets to the
rear panel using two 4-40 x 1/4" (6.4 mm) flat head screws, two #4 split
lock washers, and two 4-40 nuts. This hardware is shown in Figure 24 (at
top).
Cut two lengths of #20 insulated hookup wire: one black, 1.5" (4
cm) long; and one red, 1.25" (3.2 cm). Remove 1/4" (6 mm) of insulation
from each end of both wires.
Solder one end of the red wire to the center pin of the antenna
connector (J2) as shown in Figure 24, Detail A2. Remove any excess
solder from the outside of the pin using desoldering braid.
Solder one end of the black wire to the solder lug.
Make a 1" long jumper using a discarded component lead (from a
small resistor or capacitor). Solder one end of this jumper to the center pin
of J2, as close to the body of the connector as possible (Detail A2). Leave
the other end free, oriented as shown.
Remove the finishing nut from the external speaker jack (J6).
Install the rear panel assembly onto the KPA100 PC board,
threading J2's red wire through the center of transformer T4. At the
same time, insert J3's leads into their holes.
Verify that the red wire from J2 has been passed through T4
Secure J6 (EXT SPKR) to the rear panel with its finishing nut.
Secure J8 (AUX I/O jack) to the rear panel using two male-female
standoffs. Do not overtighten the standoffs.
Secure E1 (GND) to rear panel with the 6-32 thumbscrew, 6-32 nut,
and two #6 flat washers. The nut must be installed between the washers
and thumb screw as shown to ensure good electrical contact.
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The rear panel should now be flush with the back edge of the PC
board. If not, one of the connectors may not be properly installed.
Solder J3's leads to the board. These connections are critical to
reliable operation. The solder should coat J3's pads on both sides of
the board, and the joints should be clean and shiny.
Trim J3's leads on the bottom of the board.