Elecraft KX1 Manual User Manual
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E
LECRAFT
Your kit includes an extra 22 k resistor (red-red-orange) for
use at R32. This resistor is not present on the Revision B or B1 PC
boards. It must be soldered in place in the location shown below,
on the bottom of the board between pins 2 and 3 of U4 (LM386N).
(It could also be soldered across the pins of C19, nearby, which
may be easier.) Trim and bend the leads approximately as shown.
Make sure R32 is pressed flat against the bottom of the
board. Its leads must not be touching any adjacent pads, traces, or
components.
Visual Inspection
Verify correct orientation (banded end) of diode D4, using the
parts placement drawing (Appendix F).
Verify the correct orientation of each electrolytic capacitor. The
side of the capacitor with the strip and minus ( - ) sign must face away
from the + sign printed on the board.
Examine both sides of the PC board closely for solder bridges,
cold solder joints, or unsoldered components.
Resistance Checks
Make the resistance checks listed below with your DMM’s
negative (-) lead connected to circuit board ground at the hole next to
capacitor C6.
Test Point (+)
Resistance
U4 pins 2 & 3
> 10k
U4 pin 4
< 5 ohms
U4 pin 6
> 1k
U4 all other pins
> 10k
U5 pin 3
< 5 ohms
U5 pin 4, 5, 6 & 8
> 1k
U5 all other pins
> 10k
U6 pin 3
< 5 ohms
U6 pins 4, 5, 6 & 8
>1k
U6 all other pins
> 10k