THE GREAT MULLARD MAGIC BLOG — mazda

WHAT CAN YOU TELL ME ABOUT THE MAZDA VALVE NUMBERING CODE?

Posted by STEVE M on

WHAT CAN YOU TELL ME ABOUT THE MAZDA VALVE NUMBERING CODE?

Well, Mazda were another manufacturer who wanted to stand out and indeed made their own version of the Octal base with a fatter spigot known as the Mazda Octal or MO base.    Their valve numbering system was a bit kooky too and needs some explanation.  The typical Mazda valve type number was an alphanumeric affair comprising of; a numerical prefix followed by a letter which in turn was followed by a mumerical suffix. The numerical prefix always indicated the heater voltage EXCEPT where 10, 20 & 30 were used which indicated the heater current draw in 0.1A.  A further...

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A PRIMER ON VALVE BASES - WHEN WERE CERTAIN TYPES INTRODUCED?

Posted by STEVE MYCIUNKA on

A PRIMER ON VALVE BASES - WHEN WERE CERTAIN TYPES INTRODUCED?

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...

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