I am installing a new Cobra 29XL CB (haven't used one since the '70's) as well as a BCT15 and a BCD996 in my '05 Ford Excursion and am concerned about antenna separation. I have a decent amount of roof area to work with but a rooftop air deflector will be taking up about 30" of the rear section. I should be able to leave just enough room to stick the CB's mag mount at the very rear edge of the roof behind the air deflector as long as that position won't be a problem ground plane wise. In the rearmost position I'm pretty sure I'll have good enough separation to avoid any issues with the scanners. But if the rear position and it's less than ideal ground plane situation will cause me performance issues with tx/rx I will need to move that CB antenna a lot closer to the scanner ants. How far do I need to keep them apart to prevent any harm to the scanners?