I have upgraded to a 1 watt radio, but even with good dipole antennas I am only getting around 800 meters through trees and buildings (much more when up in the air of course). Better antennas may help, but I am considering using more power and 5 watt amplifiers appear to be possible to connect to the 3DR/Hope transmitter modules. I am concerned about transmitting and receiving with one module though. Has anyone done this before and know if the receiver circuit could be disconnected from the transmitter and bypass the 5 watt amplifier, so that it could transmit and receive half duplex with one antenna?
In the US the FCC frowns on that. If you have a valid FCC Ham license you can legally increase your power to 1.5 Watts. With the right antennas that should get you about a 5 mile range. But now you would be violating the FAA regulations. The fine now is $250,000.00 and up to I think 10 years in federal prison. ARS K7OOZ
Yes, that would be nice. You might have to overpower the other person's transmitter. A 5 watt linear amplifier would probably work for transmitting and you could use a second module for receiving (and two antennas), but it might be worth experimenting to see if you could connect the receiver to the transmitter and have one small module.