Elecraft K2 Owner's Manual - Manual (Page 14)

E
LECRAFT ® 13
4. Control Board
The Control board is the "brain" of the K2. It monitors all signals
during receive and transmit, and handles display and control functions
via the Front Panel board. The microcontroller, analog and digital
control circuits, automatic gain control (AGC), and audio amplifier are
located on this board.
Components
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Review the precautions described in the previous section
before handling any IC’s or transistors. These components can be
damaged by static discharge, and the resulting problems are often
difficult to troubleshoot.
Open the bag of components labeled CONTROL and sort the
parts into groups (resistors, diodes, capacitors, etc.). If any of the
components are unfamiliar, identify them using the illustrations in the
parts list, Appendix A.
Locate the Control board. It is the smallest of the three K2 PC
boards, labeled "K2 CONTROL" on the front side, in the lower right-
hand corner. The lower left-hand corner is notched.
Open the bag labeled MISCELLANEOUS and empty the
contents into a shallow box or pan. This will prevent loss of any of the
small hardware while allowing you to locate items as needed.
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The Allen wrenches are located in a small bag with the
MISCELLANEOUS items. These wrenches may have been oiled
during manufacturing. Remove the wrenches and wipe off the oil, if
any, then discard the bag.
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There are five sizes of 4-40 machine screws provided with the
kit. The relative sizes of the screws are shown below for identification
purposes (not to scale). All of the screws are black anodized except for
the 7/16" (11 mm) screws. The 3/16" (4.8 mm) pan-head screws are
the most numerous, and will be referred to as chassis screws
throughout the manual. There is only one flat-head, 3/16" screw.
Flat-head, 3/16” (4.8 mm)
Pan-head, 3/16” (4.8 mm)
(chassis screws)
Pan-head, 3/8” (9.5 mm)
Pan-head, 1/2” (12.7 mm)
Pan-head, 7/16” (11 mm)
Identify all of the 4-40 screws and sort them into groups.