Elecraft KNB1 Manual - Manual (Page 3)

3
Assembly
i
A fine-point, temperature-controlled soldering iron is required to assemble this kit.
Excessive heat and/or large iron tips may damage pads and traces on the PC board.
i
During assembly, we’ll refer to the top and bottom sides of the PC board. The top side
has most of the components. The bottom side has the model number and PC board revision.
(Note: The model number is KNB1. The revision C board is incorrectly labeled KBN1.)
Install resistors R1 (180 ohms, brown-gray-brown) and R2 (3.9k, orange-white-red) on the
bottom of the board. Solder them on the top side.
Install Diode D1 on the top side of the board. Orient the banded end of the diode as indicated
by its PC board outline. (D2 will be installed in a later step.)
Install resistor networks RP1 (470 ohms, 10 pins) and RP2 (27 k, 8 pins). (Be careful not to
confuse RP2 with connector P1, which also has 8 pins.) These networks are symmetrical and can
be installed in either of two orientations.
Locate the outline for transistor Q5. Adjacent to Q5 is a capacitor that may be labeled “C6”
(rev. C PC board) or “C9” (rev. D and later). Install C9 at this location (.001 µF, “102”).
Note: Do not pull on the leads of small capacitors, which can be fragile.
Install the following capacitors:
__ C3 (10 pf) __ C1 (180 pF, “181”) __ C11 (0.1 µF, “104”)
__ C4 (.01 µF, “103”) __ C5 (.01 µF, “103”)
__ C6 (.01 µF, “103”) __ C7 (.01 µF, “103”)
Note: The revision C PC board has a location for C8. This capacitor is not used.
If your PC board is revision D or later, install: __ C12 (10 pF) and __ C13 (.001 µF, “102”).
Install trimmer capacitor C2, with its flat side oriented as indicated by its PC board outline.
Install the 2N3906 transistors, Q3 and Q8. Orient the flat side of each transistor as shown by
its PC board outline. Keep lead length above the board no longer than about 1/8” (3 mm).
Install the 2N4124 transistors, Q1, Q2, Q4, and Q7.
Install the 2N7000 transistors, Q5 and Q6.
Install electrolytic capacitor C10 (2.2 µF), noting the orientation of the [+] lead. (Note: The
rev. C board has a disc capacitor outline at this location, with no [+] mark. Pre-form the leads of
C10 to fit the wider pad spacing. Orient the [-] lead toward Q8 and the [+] lead toward RP1.)