I have a 4 band vertical ant (10-15-17@20 meter) that needs no raidles. my question is how well will this work if i put it on tope of my 40 foot well grounder tower?
Tell us what kind of antenna it is? If it truly needs no radials (very few types fit that mold), then it should work fine atop your 40 foot tower. If it is a quarter wave vertical with nothing more than a manufacturer's note saying it will work without radials, then be aware that manufacturers know exactly how to stretch the truth. It really does need radials to work efficiently, but you could make some contacts without radials. Just like you can make some contacts by loading a metal bedspring set. Or a slinky.
just what kinda anti do you have that wrks with out radials ???.I have a nose problem es I am nosy .I buildt one from a old 11 mtr 5/8 wave added a few ft es it wrkd ok for 2,10,20,es 30. it is long for some short for some but tunes well for all.I added 24 radials all of different lengths in sets of four of course es man it went wide open.it is setting on top of the roof on a home brw quad pod I buildt ,it wrks all modes well but it needed radials for the final touch, looks like a big red es white spider on the house or thats wht the kids say. happy dxing.
There are a few verticals on the market that are basically off center feed cap loaded dipoles to shorten them up. GAP antennas come to mind. Cushcraft R8... I dunno of many others though.