Hello All,
Thought I'd do something different since I had off for Presidents Day. I have four each 5W US Navy "Pliotron" transmitting tubes (VT-14/CG-1162) made by GE in 1918. They have a filament rating of 7.5VDC at around 1 amp. I thought I'd try a 6VDC lantern battery to see if they actually would light up. Filament continuity checked good so I thought I'd give it a try.
Naturally, each tube would have to be "burned in" for at least 24 hours and then plate voltage applied under a load. Since they didn't use getters (chemical and metallic getters may not have been known at that time) to burn off occluded gases due to the metalurgical interaction with the silica, etc., in the glass envelope under a vacuum.
If the picture doesn't appear, try this link:
http://mysite.verizon.net/vzep5yv6/http://mysite.verizon.net/vzep5yv6/