I dialed mine in at 12' and mounted it at 52' to base and it got a tiny bit worse and now I cant reach it ;( do what you have to do with the radiator length and the matching ring to get it as FLAT as possible before it goes into the air ! Mine went from 1:1 at 12' across the 40 to 1:1.03-1:1.7 across the 40 when it went up . If your not flat on the ground it will only get worse ..
Best Omni I have ever owned though ! I had the v5/8 then the radials sagged so I got the 5/8-5000 and its a beefy performer no doubt !!
My 2 Cents , 73's 4-2-Zero New Jersey . Brian