Elecraft K2 Owner's Manual - Manual (Page 22)

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LECRAFT ® 21
Key Shaping Components (Required)
Your K2 kit includes recent changes that provide an optimized keying envelope shape (sigmoidal, or S-shaped leading and trailing edges).
The result is completely click-free CW transmission. Two of the parts for this change must be installed on the back of the Control board as
described below.
Locate the green insulated hookup wire. Strip two 1/4" (6.4 mm) lengths of insulation from one end of the wire. These will be used to insulate
the leads of C46 in the following steps.
Slip the two lengths of insulation over the leads of a .01 µf capacitor ("103"). This is a new component (C46), not present on the board.
i
Figure 4-11, below, shows the bottom side of the Control board. Components shown with dotted outlines are located on the top side.
On the bottom side of the Control board, solder C46 between R21 and the base lead of Q8 as shown below. Keep lead length short.
Figure 4-11
A 22 µF electrolytic capacitor has also been added (C45). Solder C45 as indicated above, between U8 pin 2 (+ lead) and U8 pin 14 (- lead).
Carefully compare your installation of C46 and C45 to Figure 4-11. Make sure the leads of these capacitors are soldered to the indicated pads.
Verify the orientation of the (+) and (-) leads on C45.