Hi Mark, the higher and clearer in the air you can get your antenna, the better will be your range and reception. 1090 MHz is line of sight (although certain weather and atmospheric conditions can give some freaky reception of all radio frequencies). A masthead amp or pre-amp just inside the loft where cable is routed in will also help. A pre-amp needs to be as close to the antenna itself as possible, so it can amplify the desired RF signal rather than background "noise". Some have a pre-amp at the rear of the Box, but (IMO) I don't see how this is really going to help anything, as the insertion of the pre-amp causes some loss of desired signal and is just boosting the whole signal unless there are some very efficient and clever filters built in. Hope this helps and doesn't just confuse!