In reading bunker of doom on the 50B5 & the 50C5 they are the same. What is the difference between the two & why were they done that way? Was working on an old set with no tube markings on the chassis (or case) & didn't know which tube to put in the set. I have both & they have 7 pins each. Was a 50B5 used in one type of set (such as AC) & a 50C5 used in another type of set (such as AC-DC)? Is one type of tube newer style & one type older style as far as year is concerned? (i.e. 1940's & 1950's or 1950's & 1960's? Since they have the same power output-- & 7 pins I guess I'm lost!

Same tube but not the same pin out.

The reason given for changing from 50B5 to 50C5 was UL requirement. A wrong tube in a socket was a shock hazard. What no one figured, now we have two tubes, 50B5 and 50C5. Get these wrong and you will have smoke.

Norm

:Same tube but not the same pin out.
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