Hi all what I'm hoping to find the answer to is if a single 400w digital ballast cause enough rf interference to cause problems and to be worrying about thanks
Depends on the ballast manufacturer, I think. I had to move a coax cable that ran 6" over my 2 600 ballasts( htg brand) , they were screwing with the picture on that one line, I was getting snow and lines. I held my new nanolux ballast up to the line when I was setting it up and I didn't get any interference on the tv.