[TowerTalk] (no subject)

[K7GCO@aol.com]

   A 25-5 hy, 50-550 ma swinging choke shorted out on me. I like the way 
these chokes work and want to rewind it.  I have rewound big power 
transformers and would like to know if there are things I need to know in 
rewinding this choke that are different from power transformers.  There have 
been articles printed on rewinding transformers--does anyone know of one on 
chokes.  This one over heated also.  How does one dissolve the varnish used?  
Cleaning all those laminations is problem.  Years ago there were guys that 
rewound transformers.  I'd like to talk to one.  Does anyone have any 
swinging chokes for sale?  Were they made for currents up to an amp?
    Swinging chokes improve regulation very effectively and don't need a 
resonating capacitor.  I have a replacement filter choke that matches the 
resonating capacitor in my linear so well the HV virtually doesn't change 
from idle to 600 ma.  That is very very rare regulation.  Another trick to 
improve regulation when using swinging chokes is to connect the bleeder to 
the input side of the choke.  The regulation went from about 8% to 2% doing 
that.  Besure to add a 5 ma bleeder to the filter capacitors permanently in 
case the choke opens up.  I've heard that the HV capacitors can accumulate a 
charge not connected to anything therefore the 5 ma bleeder connected 
permanently is a safety factor.  Chokes work just as well in the center tap 
of the HV transformer and it removes the HV strain off of it that frequently 
shorts them out.
k7gco

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