[R-390] TUBES

[Todd Bigelow - PS]

I actually have somewhere in all my 'stuff' a couple of tubes from way
back when that appear to be homemade. One has a structure inside that
looks as though someone cut it out of thin aluminum with a pair of dull
scissors. Pretty interesting...

What might be a better idea would be for someone with the connections or
wherewithall to investigate some of the companies who produced tubes and
no longer do - where did their equipment go? I seem to recall one of the
last manufacturers(maybe the last?) was in Owensboro Kentucky, or
Louisville perhaps? They shut the doors in the mid-90s if I recall
correctly. It would make more sense for someone to buy the equipment and
start up building tubes again, rather than trying to dissect and rebuild
one at home, methinks. I'd bet there are still plenty of folks out there
who know the process and ran the machines who could help out somehow.

Now....who has a few hundred kilobucks or more to play with? I'd be
willing to help bloodhound the stuff down, just don't have that kind of
pocket change available.

73 de Todd/'Boomer'  KA1KAQ

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.
>
> 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.
>
> And then there are the glass seals for the pins ...
>
> Regards,
> Bill Hawkins