The 520 and the 520s are wonderful talking and receiving rigs, and I'm sure you're interested in "freeband" SSB operation. I had one years ago that was modded for 11 meter operation, and it was nice at the time. But the mod is complicated due to location of installation and requires a knowledgeable person to do it, as the crystal must also be netted on frequency after install also. It's just not worth it to lose the 10 meter band on such a nice rig, and you will be hard pressed to find anyone who will do it. I would suggest picking up a Yaesu FT 101 line radio which simply requires plugging in a crystal to do it. Still sacrificing part of 10 meters, but easily reversable. Remember also, the 101's with the 11 meter position on the band switch may be just for receive only if the VFO mod has not already been done.