RE: Quick toriod question...

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-uswest-dot-net>" <Gary.Lau-at-compaq-dot-com>

This thread raises another question in my mind.  It appears that most
home-made toroids use aluminum foil tape as the conductive surface.  But
even though the individual strips overlap each other, the adhesive is not
conductive, and an Ohm meter will indicate that they do not in most cases
connect to each other.  Perhaps the thinking is that when we're looking at
100's of kV, a thin layer of goo is probably not going to put up much of a
fight before breaking down.  

But even so, I've always wondered whether this resistance between each tape
segment might have a significant effect on performance when a streamer wants
to suck the energy in the toroid off in a hurry.  If each "plate" in the
toroid-capacitor has a resistor and a spark gap connecting it to the disk
terminal, that can't be good.

I've always had access to EMI gasket material at work, used to seal computer
enclosures between sheet metal surfaces to keep RF energy inside the boxes.
I use this EMI gasket to connect the conductive disk to every one of the
aluminum tape strips.  An Ohm meter will show that each strip has a solid
connection to the disk.  Pictures and words of the EMI gasket as well as my
new 7" x 30" custom foam toroid may be seen at:
http://people.ne.mediaone-dot-net/lau/tesla/foamtoroid.htm
(sorry about the missing spaces on the page, still working on that...)

Back to my question - I'm wondering, am I the only person to worry about
connections between the tape strips?  How do others deal with this?

Gary Lau
Waltham, MA USA