|This roofing filter mod helps reduce the third order intermodulation from multiple strong signals in the 2 to 20 kHz region either side of the tuned frequency. Installation is simple and requires soldering B+ and ground wires. One coax is moved and a coax jumper is added.
This mod is for both the FT-1000 and the FT-1000D.
Please see our document titled "A Few Words About Roofing Filters" for more details.
Full installation instructions are available here: