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BYPASS CAPS

 * Original msg to: Esondrmn-at-aol-dot-com

 
 > From: Esondrmn-at-aol-dot-com
 > To: richard.quick-at-slug-dot-org
 > Subject: Bypass caps

 ES> Richard,

 ES> So far for filtering I have a good isolated ground, RF       
 ES> toroids in series with each transformer high voltage lead    
 ES> and a line filter in series with the transformer AC power. 

You will go far with this I can tell. 

 ES> I want to use bypass caps attached at the transformer high   
 ES> voltage outputs also.  Can you recommend a value?  

Small is better than large; with good chokes, and a dedicated RF
ground, you won't need much for a small-med coil. I believe you
have access to the ftp site? There should be a new file there
with much detailed info and specific wiring diagrams on this
exact subject if I am not mistaken. <Kukkonen-at-snakemail.hut.fi>
should be able to direct you. Generally we want a low Q capacitor
here as RF losses in the bypassing caps is desirable.

You asked a specific question: two .0007 microFarad caps, one
side connected to the HV bushing, the other side grounded to the
dedicated RF ground. Voltage rating should be twice that of the
main tank circuit caps. 

 ES> Do you use the rolled polyethylene style like the tank caps? 

No I use DC rated junk HV caps that are too lossy to be
considered for tank circuit caps.

 ES> Do they need to be in oil?  

No

 ES> Do I need any other filters?

Where would you put them? We have pretty much covered everything.
Just make sure the sparks don't strike the TV antenna :-)

Richard Quick


... If all else fails... Throw another megavolt across it!
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