# [TCML] Calculating the C of multiple Spheres for a top load ?

Carl Noggle cn at q.com
Sun Feb 26 15:07:47 MST 2012

```Hey---

The 11.4pF is for an isolated sphere, so the filed lines extend out to
the universe in all directions.  If the 4 spheres are close together
each will shield the others so that each will have only partial access
to the universe, so the C of the total array will be lower than 4x the C
of one sphere.  The intersphere distance makes a difference, too.  The
real value will probably be somewhere between the 11.4 and the 22.7,
although with wide spacing it could get close to the 45.6.  I would
advocate a reasonable primary tuning range.

---Carl

> Hell again
> I’m puzzled . If I plug in an 8” dia sphere in TM it comes up with 11.4pf, If I have four of them 4 X 11.4 = 45.6pf I would think.  Now the surface area of four of them when calculating, is equal to a 16” sphere but when I plug a 16” sphere into TM is only doubles and comes up with 22.7pf, not 45.6pf like I would think. Can anyone sheds some light on this ?  Which is correct ?
>
> Thanks JM
> _______________________________________________
> Tesla mailing list
> Tesla at pupman.com
> http://www.pupman.com/mailman/listinfo/tesla

```