Elecraft K2 Owner's Manual - Manual (Page 60)

E
LECRAFT ® 59
Review Figure 4-2 before installing Q2 in the next step. Q2 is
a ZVN4424A transistor, which has a slightly modified TO-92 package.
It is flat on both sides, and the labeling may be on the smaller flat side.
The wider flat side must be aligned with the flat side of the component
outline.
Install Q2, which is near C113 (just installed). Be sure to orient
Q2 as shown in Figure 4-2.
RFC3 is wound on an FT37-43 core (dark gray) using 16 turns of
red enamel wire (12", 30 cm). Wind this inductor in the same manner
as RFC14. Install RFC3 vertically, just to the left of W1.
Install 4.7 µH slug-tuned shielded inductors (large slot, no mark)
at L1 and L2, near the back-left edge of the board.
Install the 40-meter low-pass filter components, which are listed
below. These components are located near Q22 (2N5109 transistor
with heat sink).
__ C225, 390 (391)
__ C228, 56 (56) __ C227, 330 (331)
__ C226, 680 (681) __ C229, 220 (221)
__ L25, T44-2 (red), 14 turns #26 red enamel wire, 14" (35 cm)
__ L26, T44-2 (red), 12 turns #26 red enamel wire, 13" (33 cm)
i
The leads of some bottom-mounted components may need to
be pre-trimmed before mounting and soldering. See page 11.
Install the following components on the bottom side of the board,
starting with C207 at the back left. Once all components have been
installed, solder them on the top side, being careful not to damage any
adjacent top-mounted components.
__ C207, .001 (102) __ C216, .001 (102) __ C223, .001 (102)
__ C224, .047 (473) (bend body down before soldering)
__ C204, .001 (102) __ C208, .001 (102) __ C195, .001 (102)
(continued)
__ C133, 0.1 (104) (bend body down before soldering)
__ C135, .01 (103)
__ C122, 56 (56) __ C119, .01 (103)
__ C17, .001 (102) __ C27, .001 (102) __ C104, 68 (68)
__ C29, 12 (12) __ C28, 12 (12)
__ R34, 2.7 k (RED-VIO-RED)
__ RFC2, 100 µH (BRN-BLK-BRN) __ RFC7, 15 µH (BRN-GRN-BLK)
Install C6 (4.7pF) next to the “C6” label along the
back edge of the board as shown. Note that the center
hole is not used. These pads are labeled “J15” on the top
side of the board (for use with the K60XV option).
Locate L31, a 12 µH shielded solenoidal inductor
(black case; may not be color coded). L31 is mounted on the bottom of
the board, near the right edge.
Install the group of components listed below on the bottom of the
board. C183 is near the front left corner.
__ C183, .01 (103) __ C186, .01 (103)
__ C161, .01 (103) __ C150, 330 (331)
__ C90, .047 (473) (bend body down before soldering)
__ C157, .047 (473) (bend body down before soldering)
__ R77, 220 (RED-RED-BRN) __ R76, 10 (BRN-BLK-BLK)
__ R75, 680 (BLU-GRY-BRN) __ R94, 82 (GRY-RED-BLK)
__ R99, 270 (RED-VIO-BRN) __ R98, 270 (RED-VIO-BRN)
__ R100, 820 (GRY-RED-BRN) __ R110, 5.6 k (GRN-BLU-RED)
__ R114, 3.9k (ORG-WHT-RED) __ R18, 1 M (BRN-BLK-GRN)
__ R29, 10 k (BRN-BLK-ORG)
__ R19, 2.7 k (RED-VIO-RED)
__ RFC12, 100 µH (BRN-BLK-BRN)
__ RFC10, 1 mH (BRN-BLK-RED)