Heck Futura, not sure I know for sure either. Bardwell said to always take the camera and vtx ground to the same ground location, I just figured the least isolated ground location is battery ground itself. Maybe it is just moisture in the atmosphere at that time. But if all else fails maybe it would be worth a shot to see if it helped. I also know many add caps to filter noise and reduce voltage spikes also. I guess it just takes some trial and error, but as long as I could see I would fly it for a while to see what's what with it.