2012 Kenworth CB antenna mount

Absolutely no problem,,,until you said no drilling. Not sure about the t700 and the way mirrors are attached. Just got out or a t600 that had top and bottom mirror supports. I fabbed a plate that bolted to the top supports. Sounds like you may have something else. Your best bet might be to have a good shop run new, good quality coax in pace of the original. If it is factory coax it is probably not good quality in the first place. They could then check swr, if still bad, most likely antenna problem. Just got in a new t880. Terrible radio coax, antenna set up. Fabbed an antenna bracket that bolts on back of sleeper and sets the antennas just barely to the outside of the cab. Just bolted it on today and drilled a hole through the floor of the sleeper for the coax. And I wil need to run a ground from the bracket to the frame.. Will let you know how it performs.