Elecraft K3 Assembly Manual - Manual (Page 12)

11
Assembly
IMPORTANT ASSEMBLY INFORMATION
1. Screws and other Fasteners: A variety of screws and fasteners are used to assemble your K3:
 Stainless Steel Hardware Kit: If you purchased the optional hardware kit that provides
stainless steel hardware for the external fasteners, the letters (SS) are included in the procedure
wherever you should use the stainless steel parts instead of the parts supplied with this kit.
 Use your rule to check the length of screws and standoffs before installing them. Some
components are only 1/16” different from others but using the wrong size may result in parts not
fitting correctly, possibly damage electrical and mechanical components. See Screws on page 9
and Standoffs on page 10 for more measurement instructions.
 Loosen screws as needed for a proper fit. When mounting parts with multiple screws or
adjacent parts that fit together, such as the exterior cabinet panels, loosen adjacent mounting
screws as needed to adjust the parts for the best fit. Be certain you re-tighten the screws before
proceeding.
 Ensure all screws are tight. A loose screw can cause both mechanical and electrical problems
such as intermittent operation, unexpected noise or false signals (birdies) in the receiver.
 Threads can be easily stripped if too much force is applied when tightening screws. Use the
correct size hand tool and apply only moderate torque. Do not use a power screwdriver!
2. Brief circuit descriptions are provided through the manual for those interested in the functions of the
circuits. For more detailed circuit information, consult the Theory of Operation in your Owner’s
manual.
CAUTION – TO AVOID DEGRADING THE PERFORMANCE OF YOUR K3:
DO NOT DISTURB ANY ADJUSTMENTS ON THE BOARDS!
Each board was tested and aligned for optimum performance at the factory. Any change to
these adjustments will degrade the performance of your K3 or prevent its operation
altogether. All user calibrations and adjustments are done in firmware using the front panel
menus. These are described at the appropriate points in the assembly procedures.
DO NOT ADJUST THE TURNS ON ANY TOROIDS!
The position of the turns on the cores of many toroids has been adjusted at the factory to
produce exactly the inductance needed for the circuit to work properly. Any attempt to
adjust their position or to make a coil look “nicer” may seriously degrade circuit
performance.
Also, do not attempt to fix the turns or coils in place with adhesives or other materials.
Those toroids needing support have been fixed at the factory. Adding material to the other
toroids will alter their inductance, again degrading circuit performance.
ESD SENSITIVE!
Observe ESD precautions when handling the circuit boards and whenever you are working
on your K3 with the covers off. Failure to observe ESD precautions may result in your K3
not operating at all, or operating but not meeting normal factory performance
specifications due to damaged components. See page 4 for more information.