Changing your Xmitter range is not an option. The radios are designed to a specific set of circumstances as defined by the FCC. You can install a larger battery but you should check the manufacturers specs to see how large a battery you can use. The Xmitter is designed to accept certain sizes. A larger battery (more MaH) will only increase the length of time between recharging. It will not increase the range of the radio. Larger airborne battery will only increase the flight endurance. A longer antenna is a no-no. The antenna is tuned to the radio. You should neither extend it nor shorten it. Most radios are line of sight. If you have to use binoculars to see the airplane you have already lost effective control.