Where's it say those tubes are made? The writing looks different than any Magnavox "made in great Britain" Mullards I've seen, or US tubes...am I hallucinating or do I see something like "West Germany" on there..? :scratch2:
FWIW, thats chassis model 196-10.
I had googled RETMA it stands for Radio Electronics Television Manufacturers Association. http://en.wikipedia.org/wiki/RETMA_tube_designation
They say magnavox Made in Western Germany and they do have a diamond stamp.
THATS a new one! We knew of Magnavox sourcing a lot of tubes from the Blackburn Mullard factory back then (great tubes!) but not Telefunkens! Hang on to those output tubes and don't break them, they are worth some dime and probably sound excellent if they are good!