Elecraft K2 Owner's Manual User Manual

Page 70

LECRAFT

Ferrite-bead assemblies Z1 and Z2 will be installed vertically

near transformer T3 as indicated by their component outlines. To make
these assemblies, string two ferrite beads onto a 1" (25 mm) length of
bare hookup wire (or discarded component leads) as shown in Figure
6-24.

Figure 6-24

Install Z1 and Z2, bending the leads on the bottom of the board to

hold them in place. Make sure that the beads are seated flat against the
PC board, then solder.

Locate D9, the 1N5711 diode which you identified and set aside

earlier. Install D9 near the right edge of the board.

Install electrolytic capacitors C126 (47 µF) and C137 (100 µF),

Near the "ELECRAFT" label at the center of the board. Insert the (+)
lead of each capacitor into the hole marked (+).

Install electrolytic capacitor C125 (22 µF) which is near U1.

Install Q5 (2N5109). Be sure Q5 is firmly seated on the board

and has its tab oriented as shown by the component outline before
soldering.

Install the following components on the bottom of the board,

working from left to right.

__ R63, 220 (RED-RED-BRN)

Note: bend the leads of R58 exactly as shown by its component outline.

__ R58, 180 ohms, 1/2 watt (BRN-GRY-BRN)

__ RFC8, __ RFC9, __ RFC4, 10 µH (BRN-BLK-BLK)

__ RFC6, 0.68 µH (BLU-GRY-SILVER)
__ RFC5, 10 µH (BRN-BLK-BLK)

__ R50, 1.5 ohms, 1/2-watt (BRN-GRN-GLD)

__ R48, 120 (BRN-RED-BRN)

__ R47, 47 (YEL-VIO-BLK)

__ R43, 22 (RED-RED-BLK)

__ R42, 4.7 ohms (YEL-VIO-GLD)

__ R44, 2.7 k (RED-VIO-RED)

Make sure you have separated the remaining slug-tuned shielded

inductors into 1 µH and 4.7 µH types. Install these inductors in the
order indicated below, on the top of the board. These inductors are
difficult to remove once soldered, so double-check the tops of these
parts. The 4.7 µH inductors have a large slot and the 1 µH inductors
have a small slot and a red line.

__ L3, 4.7 µH (large slot, no mark)

__ L4, 4.7 µH

__ L8, 4.7 µH

__ L9, 4.7 µH

__ L10, 1 µH (small slot, red line)

__ L11, 1 µH

__ L12, 1 µH

__ L13, 1 µH