Total posts : 45366
If you are getting that kind of range with the SSTran you have done an excellent job of optimizing it! MoJoe is right about being careful about ground lenghts.
I have the SSTran and then bough the rangemaster – certanly more money, but it can modulate up to 125%, where the SSTran maxxed out about 100%. The extra modulation probably added a mile in all directions. To take advantage of the extra modulation you will need something to drive it hard and limit the positive peaks to 125% and the negative to 95%. I use an inovonnics box to do that. This is not cheap to do – the Rangemaster + Inovonics will cost between $1,000 and $1,300 together, so you have to decide how much that extra range is worth to you.