The F600 is a board of Low Pass Filters designed to work with the A600 1.8-72MHz 600W amplifier board, but it can be used to filter output harmonics for any HF/low-VHF amplifier of 600W or lower.
This is an Advanced level kit and assumes you have a good understanding of electronics. The PCB is supplied with the surface-mount components already installed, but some of the parts supplied in this kit will require assembly and soldering.
The Control Port is used to interface with a control unit that will provide +12V @ 200mA supply and filter selection. It is designed to be easily interfaced with a microcontroller of your choice (eg: Arduino). The signals are better described in the provided Assembly Instructions.
More information on this kit can be found in this article.