[Amps] Glass Power Tube rebuilders

[R.Measures]

On Jun 6, 2004, at 9:25 AM, G0RUZ Conrad wrote:

> Rich Measurew wrote......
>
>> ð  To restore the emission of thoriated tungsten filament,  glass
>> envelope tube, the vacuum pump connecting tube is opened, acetylene 
>> gas
>> is introduced, the filament is lit, and tungsten di carbide slowly
>> reforms on the surface of the filament.  When a sufficient layer has
>> been formed, a vacuum pump is connected, the vacuum is restored, and
>> the pumping tube is melted closed.  Thus, there is no need to cut the
>> tube apart.
>>
>> cheers
>
> Is that actually a rebuild?

  That's what it's called.

> That just sounds like restoring the 'chemistry'.

  Agreed

> Surely a rebuild requires the total removal of the 'innards'. I can't 
> for
> the life of me see how this can be done without the glass envelope 
> alignment
> being altered.

  Why would a rebuild require removal of the innards if the only 
problem with them is a depletion of the carbide layer that does most of 
the emitting?  A little acetylene gas, light the filament, vent the H2 
byproduct, pump the vacuum, seal it, and it's good to go another 
20k-hours.
-  cheerz, Conrad.
>
Richard L. Measures, AG6K, 805.386.3734.  www.somis.org