Elecraft K3 Assembly Manual - Manual (Page 53)

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KSYN3 Synthesizer
KSYN3 Description
The KSYN3 module is a high-performance, wide-range synthesizer covering 8 to 46 MHz. It uses a crystal-
filtered DDS (direct digital synthesis) reference. This in turn drives a VCO with a high C/L ratio, resulting in
very low phase noise. See Theory of Operation, KSYN3, in the K3 Owner’s Manual for more information.
The KSYN3 is supplied with a stiff metal plate covering the front of the pc board. This plate keeps the board
from vibrating, especially if the K3 is operated with its internal speaker at high volumes.
KSYN3 Installation Procedure
Confirm that the screw, washer and nut are mounted on the bottom corner of the KSYN3 board as shown in
Figure 72. Install them if they are not already. Note that the nut is on the side with the stiffener plate.
CAUTION
The hardware should be tightened only enough to begin to compress the lock washer.
Over-tightening may compress the thin adhesive between the stiffener plate and the pc
board, causing short circuits under the stiffener plate.
Figure 72 Stiffener Fastener on KSYN3 Board.
Inspect the bottom of the KSYN3 board to ensure no leads are higher than the chokes as shown below. The
chokes are the highest of the black surface-mount components on the board. Use your diagonal cutters to trim
any excessively long leads close to the board.
CAUTION
The objective is to be certain no bare leads touch the front panel shield when the board
is installed in the next step. Do not add spacers or insulating material between the board
and the front panel shield. It is important for proper shielding of the circuits that the
board sit very close to the front panel shield.
Figure 73. Checking Lead Lengths on KSYN3 Board.