Figure 10. Installing Q3 Hardware On Rf Board; Figure 11. Installing Crystal I.f. Filters On Rf Board - ELECRAFT K3 Assembly Manual

Install hardware to attach the heat sink of Q3 to the RF board near the rear left corner as shown in Figure 10
and Figure 12 on page 14.
ESD SENSITIVE!
WEAR A GROUNDED
WRIST STRAP OR TOUCH
AN UNPAINTED METAL GROUND
BEFORE HANDLING THE RF BOARD.
Install the crystal I.F. filters as shown in Figure 11, below, and Figure 12 on page 14. If you have more than
one filter, install them with the widest bandwidth nearest the FL1 position. For example, 2.8 kHz and 400 Hz
filters are shown. The 2.8 kHz filter is in position FL1 and the 400 Hz filter is in position FL2. If plan to add
filters later, spaces may be left for them. For example, if you plan to add the FM or a 6 kHz AM filter later, you
can leave spaces FL1 and FL2 open for them and install the 2.8 kHz filter in position FL3. The filters are not
hard to move about later, so if you aren't sure, install the widest at FL1, the next widest at FL2 and so on.
1) Use screws no longer than 1/4" (6.4 mm) as specified. Use your ruler to measure the
screws before installing them. Longer screws may extend into the filter unit and destroy it.
2) Do not over-tighten the screws. Too much torque may pull the threaded bushing out of
the bottom of the filter module.
ESD SENSITIVE!
WEAR A GROUNDED
WRIST STRAP OR TOUCH
AN UNPAINTED METAL GROUND
BEFORE HANDLING THE RF BOARD.
#4 INTERNAL TOOTH
LOCK WASHER
CIRCUIT
BOARD
4-40 7/16" (11 mm)
ZINC PAN HEAD SCREW

Figure 10. Installing Q3 Hardware on RF Board.

CAUTION
RF BOARD - TOP SIDE
FILTERS MUST BE INSTALLED
IN THE CORRECT POSITIONS.
SEE TEXT FOR DETAILS.
4-40 1/4" (6.4 mm)
ZINC PAN HEAD
SCREW

Figure 11. Installing Crystal I.F. Filters on RF Board.

#4 NUT
Q3
RF BOARD LEFT REAR CORNER
#4 INSIDE
TOOTH
WASHER
13