THE GREAT MULLARD MAGIC BLOG — tungsten drawing

VALVE TYPES & MANUFACTURING TECHNIQUES (iv) - TUNGSTEN WIRE

Posted by STEVE M on

VALVE TYPES & MANUFACTURING TECHNIQUES (iv) - TUNGSTEN WIRE

OK,  for today's blog entry I promise that I am not going to act like a  Chemist wonk (even though I am one!)  but rather instead, a thermionic wonk ( because I am one as well)!!!!!.     Last time, we took a look at Tungsten, an essential commodity used in wire for just about every valve ever made.  We left the story at the metallic powdered tungsten stage and picking up the tale again, here we have a nice ex-Mullard photo of a batch of the fine dark grey powdered tungsten leaving one of Mullard Blackburn's reduction furnaces: -...

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VALVE TYPES & MANUFACTURING TECHNIQUES (iii) - TUNGSTEN

Posted by STEVE M on

VALVE TYPES & MANUFACTURING TECHNIQUES (iii) - TUNGSTEN

We've seen so far in my blog series on valve types and manufacturing techniques that fine wire is an important material used in the valve making process. To recap, tungsten wire is used as filament wire with molybdenum being used as grid and filament supports. Just to give you an idea of HOW essential this material was, in the Mullard Blackburn plant heyday of the early 1950s over 2500 MILES, yes, MILES of wire was used every WEEK in valve manufacture. So, where does the tungsten come from?, how is it formed into wire?, well paisan, read on and all...

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