This will show you how to add a bi-directional, 2.4 GHz amplifier to your Proxim Symphony for under $100. Bi-directional means you can mount the amplifier at the antenna to help overcome any cable loss, and the amplifier will automatically switch between receive and transmit modes.
http://www.qsl.net/n9zia/wireless/appendixD.html
2.3 GHz Power audio amplifier circuit diagram and components.
http://www.qsl.net/n9zia/wireless/tpap/index.html
Provides 1dB compression output power of 23W at 12V and a 11dB gain.
http://www.qsl.net/n9zia/wireless/c54/index.html
1 Watt 2.3 GHz RF Amplifier Using a MRF2001
http://www.qsl.net/n9zia/wireless/mrf2001/index.html
Uses RF2126 at around 6.5 volts for slightly more power output.
http://www.qsl.net/n9zia/wireless/new-prox-amp.html