Elecraft K3EXREF - Manual (Page 11)

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If your K3 is equipped with the K144XV 2-meter option, reconnect the coaxial TMP cables to the
K144XV module and mount the module on the side panel using the three 6-32 black flat head screws you
removed earlier.
Replace the chassis stiffener bar using two 4-40 3/16” (4.8 mm) black flat head screws at the ends. If the
KPA3 is installed, attach the stiffener to the shield using two 4-40 1/4” (6.4 mm) screws with lock washers
under the screws. (Some stiffener bars do not have threaded PEM nuts attached. In that case, secure the screws
with 4-40 nuts and place the lock washers under the nuts).
Hold the top cover above the K3 and route the speaker wire under the stiffener bar. If you have the
K144XV 2-meter option installed, route the speaker cable under the stiffener bar at the depression in the top of
the K144XV module as shown in Figure 10. Plug the speaker cable into P25 on the KIO3 board at the left rear
of the K3.
Figure 10. Connecting the Speaker Cable.
Position the top cover on the K3. Note that the tab on the back center goes under the rear lip of the K3 rear
panel. Secure the top cover with the nine 4-40 3/16” (4.8 mm) black flat head screws you removed earlier (see
Figure 1 on page 6 for the screw locations).
REPLACE ALL THE SCREWS!
The K3's chassis has excellent rigidity despite its light weight. The screws that hold the top
cover in place are an important part of the structural design. Please be sure to replace all the
screws and verify they are tight whenever you replace the cover or other panels. When
finished you should have one 1/4” 4-40 zinc pan head screw, one inside tooth lock washer and
one split lock washer left over (the parts you removed from the KREF3 board).
If needed, install the SMA-BNC adapter on the rear panel REF. connector you installed earlier.
See Using the K3EXREF on pg 4 to confirm it is operating correctly.
That completes the installation of your K3EXREF Option.