3
Firmware Requirements
The KFL1-4 four-band Filter board does not require upgraded K1 firmware to operate. The main
microcontroller in the K1 (U1 on the Front Panel board) will recognize whether a 2- or 4-band filter board
is present at power-on.
The KAT1 (automatic antenna tuner option) firmware will also work with the 4-band module.
Filter Board Assembly
i
A fine-point, temperature-controlled soldering iron or soldering station (700-800 degrees F)
is strongly recommended to assemble the KFL1-4 PC board.
If you don't have a soldering station, check
our web site (Builder Resources page) for suggested models. A higher-wattage iron or one with a wide tip
may damage components, pads, or traces.
Locate the KFL1-4 PC board and identify the top and bottom sides. The side of the board with the
label "KFL1-4" is the top.
Orient the board so that the top side is facing up. The large notch in the board should be to the lower
right.
Locate the position of resistor R1, along the front edge of the board (top side). The label "R1" appears
to the right of the resistor's outline.
Install a 100-ohm resistor (brown-black-brown) at R1. (Don't confuse it with RF choke RFC1, which
is larger.) Make sure it is seated flat on the board, then bend the leads outward slightly to hold it in place.
Solder R1 from the bottom side of the board. Then trim the leads as close as possible to the solder
joints.
Note:
Many builders prefer to trim leads before soldering. Either order will work.
