Elecraft KAT1 Manual - Manual (Page 7)

7
K1 Filter Board Preparation
Remove the K1’s top cover (four screws).
Remove the three screws holding the Filter board in place, and unplug the board.
Install a 3-pin female connector (FIL-J1) on the top side of the Filter board. Before soldering, make
sure that the connector is flat against the board and is not tilted.
Remove the jumper between pins 2 and 10 of J2 on the Filter board. Wick out any residual solder.
Install a 10-pin, dual-row female connector (FIL-J2) on the top side of the Filter board. Before
soldering, make sure that the connector is flat against the board and is not tilted.
If you have any additional Filter boards, repeat the previous three steps for each one.
If any of your Filter boards are not aligned, you should align them now as described in the K1
owner’s manual. Filter board alignment cannot be done with the KAT1 installed, since the KAT1 module
prevents access to the slug-tuned inductors. See page 40, Band-Pass Filter Alignment, and page 46,
Preparation for Transmit Alignment.
K1 RF Board Preparation
Remove the K1’s bottom cover (four screws, plus the connector hardware).
Locate R36 on the RF board, near the antenna jack. Unsolder the lead of R36 that is closest to the
jack. Bend the resistor up and away from the board, but do not remove it completely. Note: R36 will need
to be re-connected if you have to align a new Filter board.
i
The following five steps are only necessary if you have revision D or earlier of the K1 RF
board. On later revisions, these parts will already have been installed during RF board assembly.
Install resistor RF-R39 (1.8 k, brown-gray-red) on the bottom of the RF board between Q14 base and
ground, if you haven’t already. This is described in detail on page 31 of the K1 owner’s manual (right
column, last assembly step).
Solder capacitor RF-C76 (.01 µF, “103”) across RF-R39, the resistor in the previous step. Use short
leads, and fold the capacitor down so it won’t hit the bottom cover.