Re: Grounding Problem???

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

Original poster: "Malcolm Watts by way of Terry Fritz <twftesla-at-qwest-dot-net>" <m.j.watts-at-massey.ac.nz>

Hi Marry,

On 24 Jan 2002, at 7:56, Tesla list wrote:

> Original poster: "Marry Krutsch by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <u236-at-earthlink-dot-net>
> 
> Hi John, Scot, All
> 
> 	I have tried loosening the coupling quite a bit.  To get rid of the
> racing sparks the coupling must be around 0.08.  Spark length is pitiful
> in that case.  I have tuned the coil as well as I can.  The tuning point
> is about 1.5 turns in from the calculated point.  Moving the tap just
> decreases spark length.  I am running a 6 inch coil using two of those
> GE copier xfmrs for a supply.  I'm using a 0.1 uF cap, for a bang size
> of approx. 5 joules.  My specs are in the "Help! suicidal secondary"
> thread, except that I'm now using a smaller toroid of 6" by 22".  I
> tried a 0.066 uF cap, but racing sparks remain.  Spark length goes in
> the toilet too.  On a good humid night, I can get a few 6 ft. strikes to
> the ground.  Dry nights give short streamers, and long racing sparks
> :-(.  I can't believe that I could be overpowering an epoxy coated 6 by
> 28 inch secondary with 1600 VA.

It is not a power problem but an energy one. 5J is developing too 
high a voltage for a secondary that size (and length in particular). 
I'm getting 5'+ from a 4' tall secondary using around 4J/bang and not 
a hint of racing sparks. Not only is the taller secondary able to 
handle higher voltages but it is developing lower voltages for the 
same energy as well.

Regards,
Malcolm