[Amps] pink ceramics
Ian White, G3SEK
G3SEK at ifwtech.co.uk
Thu Aug 21 09:35:51 EDT 2003
John T. M. Lyles wrote:
>Pink ceramic was high in magnesium content I believe.
From http://www.svetlana.com/docs/tubeFAQ.html
Q. Why is your ceramic pink?
A. Svetlana ceramic power tubes are manufactured with high-purity,
high-alumina ceramic with chromium and manganese additives. The
combination of chromium and manganese with high alumina ceramic results
in a true chemical bond in the metal-to-ceramic brazing process. These
additives also give Svetlana ceramic tubes their distinctive appearance.
The stronger bond allows a higher processing temperature than typically
used by manufacturers in the West. A high-temperature bake-out process
drives gasses from the internal electrodes during vacuum processing.
Clean high-temperature processing means long operating life
> It came from the Frenchtown ceramic factory, and was used by RCA for
>many years on their expensive Cermelox tetrodes and other big tubes (up
>to $100K in value). Purple/pink hue came in some Russian tubes from
>their own similar source. The US source has dried up, and now alumina
>ceramics come from others like Coors
Peter and I both knew that stuff wasn't fit to drink.
--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
Editor, 'The VHF/UHF DX Book'
http://www.ifwtech.co.uk/g3sek
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