OT Don't read this (was Re: Altair MBL source)
chenmel at earthlink.net
Wed Apr 20 21:50:10 CDT 2005
On Thu, 21 Apr 2005 00:07:17 +0100 (BST)
ard at p850ug1.demon.co.uk (Tony Duell) wrote:
> > If things had worked out differently we might be using
> > ultraminiature electron tubes. Imagine! An entire flipflop in one
> > package!
> I nthe 1920's, Lowe (in Germany) made a radio receiver which consisted
> of a tuend ciruit, headphones, batteries, and a single glass envelope.
> That contained 3 triodes and all the R's and C's.
> The idea did not catch on. The single glass device was expensive, and
> if any part failed you ad to replace the whole thing. Other radios
> were much cheaper to repair.
> A flip-flop valve would certainly be possible.
My 'EPROM Eraser' uses a multi-element tube. It's actually an old quack
medical device from the 1950's. It's a big 'cold quartz' UV lamp, and
has a high voltage power supply in the base that uses one of the 'newer'
versions of a multifunction tube, the 117L7GT, which is a tube with a
117 volt filament and (I believe) several different tube stages.
Probably the _last_ versions of multifunction vacuum tubes were the
'Compactron' tubes, specifically designed multi-element tubes used in
the 60's and 70's in sets sets designed to use with fewer tubes, i.e.
portable tube-type televisions. Compactrons were in an envelope similar
in shape to the common 7 and 9 pin mini tubes, but bigger with (if I
recall correctly) 12 pins.
Before anybody comments with alarm, yes, I know that the EPROM eraser is
VERY dangerous (totally unshielded and a fairly powerful light source)
but it's constructed in such a way that the light source can be
positioned directly over a conductive mat of EPROMs so no light escapes,
which is how I use it. I'm not sure what medical claims were made
regarding it, but I did once find it 'displayed' on a website of
historical Quack Medical devices. I guess you could do 'therapy' like
staring into the bright blue quartz tube to go blind or something...
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