[Boatanchors] Re: 6211 tube

[Barry L. Ornitz]

I believe it was Bob Mattson, W2AMI, who started the thread on 
the 6211 tube.  There have been lots of interesting responses. 
It does have the same pinout as a 12AT/AU/AX7 but it is not 
interchangeable.  I found the following information...

>From the Sylvania datasheet:

"The Sylvania Type 6211 is a miniature, medium mu, twin triode 
designed for frequency divider circuits in electronic 
computers, and other 'on-off' control applications involving 
long periods of operation under cutoff conditions."

>From the Philips datasheet:

"Special Quality double triode with separate cathodes for use 
in computer circuits.  The 6211 will maintain its emission 
after long periods of operation under cut-off conditions but 
is not intended to be used in circuits critical as to hum, 
microphony, or noise."

Interestingly, the Philips datasheet gives specifications on 
when the tube has reached the end of its useable life.  I can 
send these datasheets in Adobe PDF format to anyone who wants 
them.

        73,  Barry L. Ornitz     WA4VZQ     ornitz@tricon.net