[Boatanchors] [Glowbugs] Heater choke

Kludge wh7hg.hi at gmail.com
Tue Mar 8 22:27:14 EST 2011


From: Ian Wilson [mailto:ianmwilson73 at gmail.com] 
Grounded-grid amplifiers using directly heated tubes? 
 
Possibly.  I remember it being like the single layer RF chokes wound with
DCC enameled wire on a ceramic (or something) form maybe 1/2” in diameter
only with two windings running in parallel, one to each side of the heater.
I can see where this would be good for a grounded grid amp but each side of
the heater was bypassed to ground for RF and the winding supplying it was
center tapped with the tap grounded or keyed.  This is why I’m thinking it
was pre-GG and the response about the Eimac tubes comes close.  
 
OTOH, it may have been a GG amp and I’m confusing the bypass caps with
another amp.  As we all know, I am very good at getting confused.  :-)  But
the choke itself sticks most firmly in my mind as something I wanted to use
in a 1920s or 1930s Tx.
 
At least one of the articles on the
Glowbugs site (may be "Egad! A 9-Tube Amplifier") talks about this (sorry
don't have time
to find the link right now).
 
Nine tubes?  Little bitty ones run in parallel to make one big one?  :-D
 
Best regards,
 
Michael, WH7HG BL01xh WPE3ARS, ex-KN3MXO, ex-K3MXO A&P PP BGI LS/MFT
Whirled Infamous Author and all around really strange person
http://www.nationalmssociety.org/chapters/NTH/index.aspx 
http://wh7hg.blogspot.com/ 
http://kludges-other-blog.blogspot.com
<http://kludges-other-blog.blogspot.com/>  
Hiki Nô! 
 
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