Elecraft KX1 Manual - Manual (Page 26)

E
LECRAFT 25
Install U9 (77L06) below RP5 on the lower edge of the board
using the same procedure that you used for U8 above. Be sure the top
of the device is no more than 5/16” (7.9 mm) above the board.
Install transistor Q7 (2N4124). The position for Q7 is in the upper
right quadrant of the board, about 1” (2.5 cm) down from the top edge
and 1-3/4” (4.4 cm) from the right hand edge. Be certain the top of the
transistor is no more than 5/16” (7.9 mm) above the board.
Install 8-pin integrated circuit U3 (4427) in the space provided
near the right hand edge of the board, about 1-1/4” (3.3 cm) down
from the top edge as follows:
_ Test-fit U3 to see if the pins line up with the holes in the
solder pads on the board. If needed, straighten the pins like
you did for resistor pack RP5 (see Figure 5).
_ Identify the end of U3 where pin 1 is located. It will have a
notch, a dimple, or both at this end (see Figure 11).
_ Insert U3 into the solder pad holes with the notched, pin 1
end lined up with the notch on the printed outline.
_ Spread out the pins on the opposite corners to hold U3 in
place, then solder and trim all 8 pins.
DIMPLE AT
PIN 1
NOTCH
Figure 11. IC Alignment.
Install 3-digit LED display DS1 as follows:
_ Insert the 3-digit LED display in the space bounded by
resistor packs RP1, RP2, RP3 and RP4. The pins on DS1
allow it to be inserted only one way.
_ Hold the display against the board and tack-solder pins at the
opposite corners.
_ Inspect the display carefully to ensure that it is firmly against
the board at both ends. If necessary, reheat one of the pins
and adjust the display. It is very important that the display be
fully seated and resting directly against the board at both
ends.
_ Solder and trim all 13 pins on the display.
Install encoder Z1 as follows. Z1 mounts to the left of
transistor Q7.
_ Test fit Z1 on the board. It will only go one way. The side
with three terminals is nearest the top of the board.
_ Press down on Z1 until the small nubs at each corner rest
directly against the board. It is very important that Z1 be fully
seated against the board.
_ Solder two pins on opposite corners of the encoder, then
recheck to ensure it is sitting against the board. If necessary,
reheat the solder and press down on the encoder to position it.
_ Solder the two large tabs to the plated ring around the edge of
the mounting holes. Apply only enough solder to make a
good mechanical and electrical connection between the tab
and circuit board. Do NOT try to fill the holes with solder.
_ Solder and trim all five pins.