The Music, the Technology, and the Philosophy

We learn from history that we learn nothing from history  - George Bernard Shaw

The Subject of Vacuum Tubes - Starts with Thomas Edison

CLICK>    The Edison Effect   <CLICK

 

NOTE - This enlargement from the above link.

Closeup of the filament on a low pressure mercury gas discharge lamp showing white thermionic emission mix coating on the central portion of the coil. Typically made of a mixture of barium, strontium and calcium oxides, the coating is sputtered away through normal use, often eventually resulting in lamp failure.  This coating recipe from 1882-83 was the basis for the evolution to what became known as the common oxide coated kathode.

CLICK>   More on New Jersey and Thomas Edison   <CLICK