First of all, use the ac adapter when possible for best range. the mod is here
http://www.xmfan.com/viewtopic.php?t=3257
I tried it, I did the sticker removal and just turned the pot like it said. I think it made a slight improvement but having the AC hooked up seems to have the best results
Also, tuning the audio thumbwheel on the side of the unit to where the red light is almost constant seems to overmodulate the receiving radio when it is in close by, so I only use that for far away issues.