[ARC5] [Milsurplus] Cold Filament Inrush Current

[Richard Knoppow]

    A note on filament voltage: Lowering voltage can extend the 
life but this applies ONLY to pure tungsten filaments, not to 
thoriated tungsten or indirectly heated coated filaments. Those 
generally should be run very close to rated voltage (RCA and 
Eimac specify something like +/- 5%. There is a little more to 
this, Eimac says that filaments on thoriated tungsten tubes can 
be run slightly on the low side provided emission is correct. 
Needs to be monitored for maximum tube life. For pure tungsten 
like lamps lowering voltage by 5% will about double lamp life 
with barely noticeable difference in brightness.
     I am sometimes tempted to send messages without correcting 
the spell checker. Not often.

On 3/15/2018 2:20 PM, David Stinson wrote:
> *From:*Tom Lee
> *Subject:* Re: [ARC5] [Milsurplus] Cold Filament Inrush Current
> 
> not only craxy, but crazy, too!
> 
> -- 
> 
> I like “craxy” better.

-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL