The external antenna uses a standard mini-stereo plug just like you see on iPod earphones, etc.. I have an old set of earphones that I plan to just cut the earphone part off and let the wire act as the antenna.

Even the standard 300 foot range is adequate for most cases. At our field our heli pilots have a place just outside that range and that is why I want the external antenna.

BTW at 1 point in the directions it says 300 meters and 1000 meters, then later says the range is 300 feet and 1000 feet using he external antenna and not.