I've got a new set that has some Philips ECG brand 6GH8's. They appear to be the sucessor to Sylvania. Anyone know when these tubes might have been made...early 1980's?

Chad, Im not sure of the exact date, but I remember the logo was switched when I quit working in the shop which was sometime in 1981-1982.

Somehow I had never run into these, only later Sylvania labeled tubes. Last month I got a load of NOS tubes from a retiring tv shop and lots of these with Philips ECG on the tubes. I had been wondering the same thing as to date. It seems like I remember GTE Sylvania electronics ads on tv in the early 80s.