Glowing Tubes Not During Christmas!

[Chuck W4MIL]

In a message dated 05/25/2000 6:54:39 AM Eastern Daylight Time,
optom at ATTGLOBAL.NET writes:

<< I would NOT operate ANY tube to the point of glowing red plates. The
heater of a tube is designed to glow red - not the
 plates.
  >>


Gentlemen all,

In the early 60's I was Chief Engr for a 1kw AM'er on 1490kc.....  Used a
Collins 20V-2 transmitter with 4-400's in both modulator and finals.  With
proper voltages, idle current, etc...... the plates of those finals would
glow red.  Not ur cherry, melting point red------- but red.  Approaching 100%
mod peaks on either voice or music would cause the modulators to take on a
faint red glow.  Never melted a tube and achieved normal tube life
expectancy. (Small market AM radio managers were not known for their love of
spending money for technical items, esp tubes that cost ~$50/per.....)

Just my .02 worth.

73

Chuck Milton

Sponsored by the City of Tempe 

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