In the classic QRP style Keith wanted to fit the board into an Altoids tin to be the ideal companion to his Frog sounds QRP single band 40m rig. Keith did add on the additional filter integration kit from Sotabeams for an additional £5.50.
VK3YE has done a great look at this and has a video demonstrating its use on home-brew kit. Have a look at the video to get a really good idea of how this works.
We really were blown away by the performance of this little box of tricks when we tried it on the big rigs in the shack. The filter is a brick wall when switching between wide and narrow and it is excellent to listen to. I think this filter may well be on the cards for me to pick one up very soon to play with the rigs here at M0TEF towers.