[Boatanchors] 6211 = 12AX7 ? 12AU7?

[Sheldon Daitch]

Reed,

thanks, but IIRC, there are more other four digit numbered 
tubes that are in the same family.  GE indicated a 6679 for 
the 12AT7  in the Progress Line manuals, as well as the 6681 
you mentioned below for the 12AX7.

I believe that GE had line of 5 Star 4-digit tubes that
were "superior" to the number-letter-number tubes, and
even some of the four digit versions.  Some of the
variations were for controlled filament currents and
warm-ups, for series operations, 6 volt vs 12 volt mobile
operations, in that day.

But back to the original discussion on 6211/AT/AU/AX family
lookalikes, I remember, way back, getting some old military surplus
printed circuit cards that had two tubes on the end of the
card, both tubes looked like an AT/AU/AX tube, but it had a 
number that I also could never figure out from the commercial
catalogs at the time, and somewhere way back in memory cellar,
I recall that these tubes were specifically designed as flip-flops
for old tube computer use, and had lower voltage and current 
ratings than the real AT/AX/AU family tubes. Out on limb, and
too many years of San Miguel has passed, but why does 6814 
or 6414 come up in the memory.  I haven't looked at any tube sites,
so if these really aren't legit for the point of the discussions,
just consider it a guess.

73

Sheldon
WA4MZZ


Reed Park wrote:
> 
> Sheldon Daitch wrote:
> 
> > I am really going to show my ignorance here, but weren't there at least
> > one four digit tube identifier for a tube that looked like a
> > 12AU7/12AX7, same dual triode, same mechanical look, designed
> > specifically for either vacuum tube flip-flop or multivibrator use, way
> > back where there were vacuum tube "computers?"
> >
> > Is this 6211 possibly one of these units?
> >
> > Sheldon
> >
> > Bill Beech wrote:
> > >
> > > Bob,
> > >
> > > According to my tube data, that is neither a 12AU7 nor a 12AX7.  It has
> > > lower plate voltage ratings than either of those.  I hold no
> > > replacements for it.
> > >
> > > 73,
> > > Bill, NJ7P
> > >
> 
> 12AU7W  -  6189
> 12AU7     -  6680
> 12AT7     -  6201
> 12AX7     -  6681
> 
> 7 3
> Reed
> 
> --
> 
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