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PRIMARY TESTING

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

Quoting Ed Sonderman:

 ES> Last night I tried tapping the inside primary coil at 2      
 ES> turns and the outside at 14 turns.  I still have an intense  
 ES> corona.  I am having 4, 1.0" thick 8.0" dia, plastic discs   
 ES> made today and will try raising the secondary this weekend. 

This sounds like it will fix the problem.

 ES> I had a guy over that does commercial video shooting some    
 ES> film.  This should be interesting.  I had several intense    
 ES> hits on an overhead copper water pipe in the basement.       
 ES> Somehow this started my dishwasher which ended up getting in
 ES> an error mode that I could not reset. Turning it's power on  
 ES> and off fixed it.  This is the first time I have screwed up  
 ES> something in the house.  

Sounds funny until it blows out a $400 TV, or a $4000
entertainment system! But it would sound weird if I started
telling people to place RF grounded strike shielding around their
water pipes. I have seen entire 60 cycle circuits litterally arc
short across the switches when fixtures were inadverantly struck
with a heavy bolt.

 ES> I am rapidly running out of room in my basement.

Boy do I know this feeling...

 ES> I still have the toroid mounted 9.0" above the secondary.  
 ES> I did get one nice hot discharge again from the top of the   
 ES> secondary to the botttom.  I had previously wrapped a two    
 ES> inch strip of polyethylene around the top of the coil to     
 ES> prevent this but with this much power it did not stop it. 

A cheapy temp fix for this problem is wrapping about a dozen or
more tight turns of saran or other cling plastic food wrap around
the coil. It looks awful, but will really help supress excess
corona and breakout. I have found it helpful in highly stressed
1/4 wave systems and with Magnifier secondaries.

 ES> When I do get the secondary up, am I likely to experience    
 ES> shorting between the ground lug on the bottom over to the    
 ES> adjacent turns of the primary?  They will be only a couple   
 ES> of inches apart.  

Usually 1-1/2 inches clearance is more than enough distance to
prevent flashover between a tank circuit conductor and the system
RF ground. Remember we were talking the other day about using a
grounded center post between the electrodes in the safety gap? 
Hopefully the grounded center post at the safety gap becomes the
ground reference for the entire tank circuit, making it
exceedingly difficult for the gap to remain open while an arc
establishes a longer path elsewhere. Flashover from tight turns,
sharp corners, etc. can usually be tracked down and remedied. I
will often cut a small section of 60 mil polyethylene and insert
it where flashover and arcing may be a problem, like in between
turns on both sides of the primary tap.

Richard Quick


... If all else fails... Throw another megavolt across it!
___ Blue Wave/QWK v2.12