If you should need a simple rf source in order to test antennas, preamps, coverage and so on. Her is a simple method. I have used a 1$ keyfinder. The keyfinder respond by several beeps if some one whistles and is extra sensitive for 1750hz tone. So if you have a transceiver that is equipped with VOX, place the keyfinder near the radio. If you whistle or send a 1750hz repeater tone the keyfinder will respond by beeping, the VOX kicks in and you will hear a string of CW like beeps almost like opening a repeater. (don't forget to identify by reading up your signature)
http://i6.photobucket.com/albums/y247/drammen/1.jpg
