[Amps] Glass Power Tube rebuilders

[R.Measures]

On Jun 6, 2004, at 10:33 AM, Ian White, G3SEK wrote:

> R. Measures wrote:
>>> John was clearly talking about other problems where there *was* a=20
>>> need  to cut the tube apart.
>>
>> =01  It's probably easier to melt a hole than to cut the glass.
>
> That's "metalwork thinking". Glass plays by different rules.

=F0  I used to do some glassblowing when I was taking a chemistry class. =
=20
To make a hole in a glass tube, apply a point flame to the spot where=20
one needs a hole.  When the spot is hot, blow or suck until the glass=20
bubble pops.  If needed, a glass extension tube can then be attached at=20=

the hole by heating and sticking the glass together,
>
>>>
>>> Even cutting the base seal and re-attaching a pumping tube is very=20=

>>> difficult, because it involves using open flames close to all the=20
>>> glass/metal seals.
>>
>> =01  Open flames already were used to seal the pumping tube after=20
>> evacuation.
>
> The original production-line process had all the special tooling=20
> required (including shields to make sure the flame didn't touch the=20
> base pins) and it only involved one open-flame operation down there.

=F0  Only one open flame operation is needed to make a hole in the glass=20=

and attach a glass tube for the carburization/pump-down operation.
>
> Re-evacuating a glass tube involves three operations, and they're all=20=

> riskier than anything done during manufacture.

=F0  Pinching off a glass tube is fairly straightforward if the right=20
amount of heat is applied.    The vacuums in my 3-500Zs are still=20
there, so it must be do-able, Ian - even if the sky does fall on=20
occasion.

cheerz
Richard L. Measures, AG6K, 805.386.3734.  www.somis.org