Vacuuum tube digital circuits (50 year rule)

On 8/31/06, Michael Holley <swtpc6800comcast.net> wrote:
> I recently got a book titled High-Speed Computing
Devices 1st ED. 1950...
>
> I have been adding to my magazine scans. I found a
decade counter circuit
> implemented with four 12AU7 tubes (dual triodes) in the
October 1955 Radio &
> Television News. (50 year rule.)
> http://www.swtpc.com/mholley/ElectronicsWo
rld/Oct1955/RTVN_Oct1955.htm

Cool!  I happen to have a dozen 12AU7s here in my desk -
they were discarded
from the stock shelves when they cleared out
"Skylab", the former home for a
wad of experiments dealing with aeronomy and auroral
observation -
Carl Sassenrath of REBOL fame worked there once, many years
ago).

Hmm... a decade counter with 4 tubes... with a dozen tubes,
I'm
half-way to a digital clock - just add nixies!

Thanks for the pointer!

-ethan

On Wednesday 30 August 2006 11:58 pm, Ethan Dicks wrote:
> On 8/31/06, Michael Holley <swtpc6800comcast.net> wrote:
> > I recently got a book titled High-Speed Computing
Devices 1st ED. 1950...
> >
> > I have been adding to my magazine scans. I found a
decade counter circuit
> > implemented with four 12AU7 tubes (dual triodes)
in the October 1955
> > Radio & Television News. (50 year rule.)
> > http://www.swtpc.com/mholley/ElectronicsWo
rld/Oct1955/RTVN_Oct1955.htm
>
> Cool!  I happen to have a dozen 12AU7s here in my desk
- they were
> discarded from the stock shelves when they cleared out
"Skylab", the former
> home for a wad of experiments dealing with aeronomy and
auroral observation
> - Carl Sassenrath of REBOL fame worked there once, many
years ago).
>
> Hmm... a decade counter with 4 tubes... with a dozen
tubes, I'm
> half-way to a digital clock - just add nixies!



Anybody having any vacuum tubes they don't want,  I might
be interested.  I 
can't offer much of anything for them,  but if they're
gonna get tossed...

-- 
Member of the toughest, meanest, deadliest, most unrelenting
-- and
ablest -- form of life in this section of space,  a critter
that can
be killed but can't be tamed.  --Robert A. Heinlein,
"The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled
by lies. --James 
M Dakin

Hi,

Roy J. Tellason said:
> 
> Anybody having any vacuum tubes they don't want,  I
might be interested.  I 
> can't offer much of anything for them,  but if
they're gonna get tossed...

Just for informational purposes:  12AU7s (and 12AX7 and
12AT7) are still
available new.  You probably won't like the price, but
they're still in
production - us electric guitar players use them,

-- 
Cheers,
Stan Barr  stanbdial.pipex.com

The future was never like this!

On Thursday 31 August 2006 04:27 am, Stan Barr wrote:
> Roy J. Tellason said:
> > Anybody having any vacuum tubes they don't want, 
I might be interested. 
> > I can't offer much of anything for them,  but if
they're gonna get
> > tossed...
>
> Just for informational purposes:  12AU7s (and 12AX7 and
12AT7) are still
> available new.  You probably won't like the price, but
they're still in
> production - us electric guitar players use them,

Along with 6L6 and maybe 5U4 and some other numbers for
output tubes,  no 
doubt.  To get that "Marshall sound"...   

-- 
Member of the toughest, meanest, deadliest, most unrelenting
-- and
ablest -- form of life in this section of space,  a critter
that can
be killed but can't be tamed.  --Robert A. Heinlein,
"The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled
by lies. --James 
M Dakin