Elecraft K1 - Manual (Page 17)

16
E
LECRAFT
Insert U1 into its socket, with the notched or dimpled end of the
IC aligned with the notched end of the PC board outline. Figure 4-7
shows an 8-pin IC; U1 is similar but has 18 pins.) Press U1 down into
the socket as far as it will go.
Pin 1
Notch
Pin 1
Dimple
Figure 4-7
Note: IC pins are counted by going around the IC counter-clockwise
from pin 1.
Examine U1 closely. If any pins are bent, remove the IC and
straighten them. (To remove U1 from its socket, pry it up gently on
each end using a small flat-blade screwdriver.)
Locate the blank white area near U1. This area is provided for
labeling the Filter board with the two bands covered (e.g. "40, 20").
Use an indelible marker, dry transfers, or an adhesive label.
Uninstalled Components
All component locations on the Filter board should now be filled
except J1 and J2, which are provided for the automatic antenna tuner
(KAT1). The KAT1 option should be installed only after the basic K1
kit has been completed and tested. At that time, the jumper you
installed between pins 2 and 10 of J2 will be removed. If you’re
building a 2-band Filter board that includes 80 meters, you’ll have a
10 µF electrolytic capacitor left over at this point. This will be
installed on the RF board at C78 in a later step.
Visual Inspection
Using the parts placement drawings in Appendix F, re-check the
orientation of the relays (K1, K2, K3) and U1.
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About 90% of all problems with kits are caused by poorly-
soldered component leads. Such problems can be avoided by doing a
careful inspection of the board, preferably with a magnifying glass.
Examine the bottom of the PC board closely for cold solder joints,
solder bridges, and unsoldered components.
Resistance Checks
Make the measurements listed below, touching the meter's (+)
and (-) leads to the indicated points. Measurements at relay K3 must
be made on the bottom side. Relay pins are numbered like ICs, with
pin 1 identified by its round pad. The Filter board schematic (in
Appendix B) may help you troubleshoot any incorrect readings.
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The symbol
>
means greater than, and
<
means less than.
Your DMM may indicate infinite resistance (all digits flashing) for
readings that are listed as "> 100 k." (Do not use an analog VOM.)
Test Points (+, -) Resistance
U1 pin 6, U1 pin 7 230-270 ohms
U1 pin 6, U1 pin 8 230-270 ohms
U1 pin 6, U1 pin 12 230-270 ohms
U1 pin 13, P2 pin 6 90-110 ohms
P1 pin 1, P1 pin 3 > 100 k
P1 pin 2, P1 pin 3 > 100 k
P1 pin 3, P1 pin 4 > 100 k
P1 pin 3, P1 pin 6 > 100 k
P2 pin 1, P2 pin 2 > 100 k
P2 pin 7, P2 pin 8 > 100 k
K3 pin 2, K3 pin 9 < 5 ohms
K3 pin 4, K3 pin 7 < 5 ohms