Re: Owdin Vacuum Tube Coil

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 12/3/01 7:02:27 PM Eastern Standard Time, tesla-at-pupman-dot-com
writes:


>
> , I wonder 
> if the bottom turn of the plate coil can be tied in with the bottom turn of 
> the secondary in order to avoid having to use a true RF ground.



Richard,

That will work, but you're tying the secondary to the 60Hz HV which
seems dangerous if you touch the output arc.  It will work though,
and I did some experiments that way, but I didn't touch the arc.
DC Cox did some experiments using a primary of 40 turns, and
he connected the bottom of a free resonator coil to a tap point 
along the 40 turns,
and also used a different tap point for tuning.  He said this gives
a little better output, and indeed I tried it and did get about another
inch of spark or so.  The best tap points are found by trial and
error.  I don't use it though because the free resonator is connected
to the 60Hz Hv, and is dangerous.  When the sparks hit a ground, 
they are extra bright probably due to the 60Hz HV.

I never use a true RF ground for a tube coil. I just use the house
wiring (3rd prong) ground for all the coil grounds.  Tube coils don't
seem to cause any destruction of household devices.  Even with
my computer turned on, I can run the tube coils.  I don't recommend
it though.  

Safety first    :)
John