I prefer to run my antennas on top of the fuse, to the top of the vertical stab, but I'm guessing that your "short" range test is merely a result of the bottom location. With the antenna on top it's further away from pushrods and other potential RF generating internal components. My Futabas generally test to about 100 feet.

I know any number of people who run there's on the bottom and don't have problems with it. I do think it's more likely to get hung up and ripped out though, especially flying off a grass strip with high bushes at each end.
Dennis-