PCS-Electronics

Hello i have a question about an SuperFone 3000 unit. This is an intercom and can also function as a phone. I have a qestion about the range of this phone, on one page it is written 10km, but i done`t know how to
achieve this and which antennas to use for best performance, or maybe an amplifier, i would like an range of 20km so i can talk with my friend far away.



http://www.citde.net/shop/a13004.htm


http://www.superfone.net/CT3000.htm