[R-390] TUBES

[Joe Foley]

Bausch and Lomb in Rochester, NY could have done this
but they gave away all of the vacuum chambers we built
for them and canned all of the people who knew how to
do all of that stuff.

What do they make now?  Nothing!  Just eye wash.

Now Johnson and Johnson has the stufff to do it!!

CVC high vacumm products is in Rochester, too, they
know all about this stuff.

This wouldn't be that tough to do, like everything
else it would take MONEY!  Lots of MONEY!!

Joe




--- mikea <mikea@mikea.ath.cx> wrote:
> On Thu, Feb 14, 2002 at 04:58:28PM -0600, Bill
> Hawkins wrote:
> > Other tries at this thread revealed that the home
> tinkerer
> > might be able to build (or rebuild) an 01-A class
> tube with
> > a "soft" vacuum. IF he or she could get coated
> filament wire.
> > 
> > The tubes that we want are all hard vacuum tubes.
> It takes
> > an expensive set of vacuum pumps to get down to
> where flashing
> > the getter takes out all of the molecules left.
> 
> I seem to recall some article(s) in Scientific
> American about
> DIY pumps for getting a good, hard vacuum. I worked
> with a bunch
> of hi-vac stuff, and can attest that the commercial
> gear is
> expensive to buy, operate, maintain, and debug. 
> 
> > Making the elements for a 7 pin miniature pentode
> seems to be
> > impossible without expensive tooling - kinda like
> making a
> > turbo-pump for a Saturn V engine. Both materials
> and tools
> > will be prohibitive for short production runs.
> 
> There I agree wholeheartedly. Material composition
> would
> have to be _very_ rigidly controlled. 
>  
> > And then there are the glass seals for the pins
> ...
> 
> _That_ I don't see as a great problem, given that we
> have a way
> to produce and align the elements, put them in the
> envelope, 
> pump the critter down, seal it, fire up the getter,
> etc. Metal-
> glass seals are (relatively) simple in lab
> glasswork. Not by
> any means trivial, but vertainly no more difficult
> than a 10-
> step graded seal from quartz to Pyrex.
> 
> And it appears that the bases were mass-produced.
> One-offs, once
> the process is refined to repeatability, shouldn't
> be terribly
> hard. 
> 
> For those who want to respond, "When pigs fly", I
> have a very 
> nice flying pig hanging from the ceiling of my
> office by a 
> tether. It has nice fabbric wings, a small DC motor,
> and flaps
> in a circle on 2 AA batteries. I will accept "When
> Satan sells
> ski-lift-and-slope tickets. ifor Hell".
> 
> And I'm not saying that _any_ of it will be _easy_.
> Far from it.
> 
> -- 
> Mike Andrews
> mikea@mikea.ath.cx
> Tired old sysadmin since 1964
> _______________________________________________
> R-390 mailing list
> R-390@mailman.qth.net
> http://mailman.qth.net/mailman/listinfo/r-390


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