Thread: 6SK7 and 6SK7W
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Old 12th Feb 2021, 7:43 pm   #6
usradcoll1
Heptode
 
Join Date: Mar 2017
Location: Cedar Grove, Wisconsin, USA.
Posts: 823
Default Re: 6SK7 and 6SK7W

Quote:
Originally Posted by turretslug View Post
Supposedly, the 'W' stands for War (!), it seems to have been a post-WW2/'50s designation applied to quite a few valves supplied for US military use- 6L6, 6AL5, 6AK5, 6BA6, 6BE6 etc. often turn up with a 'W' suffix. I think that it often means a ruggedised version with detail production changes to resist shocks and vibration, rather than noticeably improved electronic performance. The 6SK7, a late-'30s modest-mu IO pentode, was getting a bit old hat in the post-war era, but this version probably illustrates that there was still a great deal of legacy electronics in the US inventory.
Another interesting thread!
I was thinking about the "Y" suffix on some metal valves. It meant a low loss mica filled yellow molded base. They were intended for high frequency use. 6SB7Y and several others. The "Loctal" valve was also intended for that application. And then, there's the Acorn valve!
Dave, USradcoll1
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