I have this antenna EFHW 40-10 from Maple Leaf Studios. My current configuration: Inverted L with feed point 3m above ground, with "L" at 9m. I have 45 20-foot in-ground radials just below the feed point, as well as two ground rods connected to the radial plate, and the ground of the match box is connected to the radial plate. My question is: Will lowering the feed point all the way to the ground hurt the performance in any way? The manufacturer recommended that the antenna be at least six feet above the ground, which most of it would be. I'd like to extend the vertical as far as possible (I'm limited as to how far I can go up, due to my mast), and reduce the length of my antenna ground. Any help is appreciated. Thanks. I like the performance and versatility of the inverted-L and, given my limited yard size, feel that this is the best all-around multiband option.
RE: "The manufacturer recommended that the antenna be at least six feet above the ground, ..."
The reason probably is related to the r-f current flowing along ~six feet of "ground" wire, and/or along the outer diameter of the shield of the coax line connected to the input transformer. Those paths form the 2nd radiating conductor/section of this antenna system, and complete the conditions needed to enable its radiation.
Greatly reducing those conductor lengths likely will reduce the radiation efficiency of that antenna system configuration.