THE GREAT MULLARD MAGIC BLOG — ct8
A PRIMER ON VALVE BASES - WHEN WERE CERTAIN TYPES INTRODUCED?
Posted by STEVE MYCIUNKA on
Mama Mia! An e-mail from Vigata in Sicily enquiring about when certain valve bases were introduced. I know a valve dealer from Sicily you know, he's from Messina and ever such a nice chap but I digress........ There exists a whole raft of valve bases, however, I shall deal with only the most commonly seen bases and their dates of introduction in the following table:- Year of Introduction Valve Base Type Descriptive notes 1916 B4 Introduced by French valve manufacturer Duclos-Fivre 1927 B4 + side screw Introduced for indirectly heated cathodes 1928 B4 + top cap VHF/ UHF anode top...