[Amps] Glass Power Tube rebuilders

[Ian White, G3SEK]

R. Measures wrote:
>> John was clearly talking about other problems where there *was* a 
>>need  to cut the tube apart.
>
>
  It's probably easier to melt a hole than to cut the glass.

That's "metalwork thinking". Glass plays by different rules.

>>
>> Even cutting the base seal and re-attaching a pumping tube is very 
>>difficult, because it involves using open flames close to all the 
>>glass/metal seals.
>
>
  Open flames already were used to seal the pumping tube after 
>evacuation.

The original production-line process had all the special tooling 
required (including shields to make sure the flame didn't touch the base 
pins) and it only involved one open-flame operation down there.

Re-evacuating a glass tube involves three operations, and they're all 
riskier than anything done during manufacture.


-- 
73 from Ian G3SEK         'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek