My bakelite and wooden 49-701 and 702 7" Philco's both have the same mild ion burn. It's suprising because I never saw it on a 7" model before. The only other set I ever had with it is a Dumont "doghouse", but it's common with them. The burn is hardly noticeable watching something and hardly distracting. I figure if I was 70+ years old I'd have some dark spots too!
