Metal tubes

In 1935 RCA launched new all metal valves (tubes) with a new octal base.  

One of the first nine metal valves was the 6F6 output pentode, soon after the first 6L6 was produced and then the 6V6.  Glass equivalents of these were manufactured in the US, Canada and Europe.  Today these glass types are still made in China and Russia.  The original metal types were never manufactured in Europe, though the US tubes were sometimes resold under British brands.

From gadgets


The first metal tubes
 6H6  photo
 6F6  photo
The second batch
 6A8Replaces 6L7 but 6K8  soon replaces.    
 6L6  photo
 6N7 QPP dual output triode 
 6J5  photo
Later types. The 6S.. types replaced those with top connections.
 6K8See Magic Three  
 6SC7  photo 
 6SG7  photo

Michael Saunby,
14 Dec 2008, 11:16