I plan on installing a 20 meter vertical antenna, since my lot size is small. I have a large tree in the middle of my back yard and around that tree is a platform/treehouse with the deck about 10 feet above the ground. I can secure a telescoping mast to the deck and trunk below it, giving me the chance to mount the vertical starting at about 30 feet above the ground (I've taken into account branches and swaying, etc.). Since this would be high above the ground my takeoff angle would be low which would be nice for dxing. The question is: since it's so high above the ground, are radials practical? It seems like the radials would radiate themselves. Or, do I just need a good ground? Thanks.