Since the U3 board is the same board as the DX IV which has RF Gain switch, I hit up srtga for some pics of the inside of his DX IV for the wiring, pulled up the schematic for the DX IV and added RF Gain to my U3. Over all it was a fun project that took me a couple of days to complete and the results are better than I expected. I took the squelch pot/switch from a spare U3 I had laying around and the parts I needed to add.
The people you hear in this video are at least 20+ miles away.
[ame="http://www.youtube.com/watch?v=L3xK3tY9GSI"]YouTube - Cobra Ultra III CB RF-Gain mod[/ame]