[Boatanchors] 6SG7 Question

[James A. (Andy) Moorer]

My understanding is that some tube manufacturers (mostly Philips in Europe) 
continued to make tubes up to about 1986 because there was a lot of military 
equipment that for some reason couldn't be replaced. Sorta like the air 
traffic control computers that were designed in the 60's, or the Z80 
computer chips that are still used in the space shuttle (yes, they get their 
spares off eBay!).

The 6SG7s probably weren't made specifically for the AR-88 in the 80's. They 
were a pretty popular tube.

I have boxes of JAN 5749 and 5751 tubes made by Philips and marked 1986.

James A. (Andy) Moorer
www.jamminpower.com

----- Original Message ----- 
>
> Can any one tell me why 6SG7s would be still being produced 40 years after 
> the AR88 was designed?
>