Re: Top-load-less TC

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

Original poster: "Barton B. Anderson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla123-at-pacbell-dot-net>

Al,
Thanks for reposting these specs. Could you please elaborate on four items:
1) The spring?
2) Where do you actually tap the primary for loaded and unloaded Ctop?
3) If Ctop, type and size?
4) Without Ctop, where do you pull arcs from? (small gizmo I assume).

Thanks,
Bart A.

Tesla list wrote:

> Original poster: "albert hassick by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <uncadoc-at-juno-dot-com>
>
> On Sun, 27 May 2001 03:03:51 -0400 albert hassick <uncadoc-at-juno-dot-com>
> writes:
> > Hi Scott, Barton.  Thanks for your interest!   OK, here goes with my
> > additional specs of the coil you requested.   Secondary:  8"
> > Quickcrete cardboard form, 24" tall, coated internally with two
> > coats of Minwax 'satin polyurethane' and sealed atop that with
> > 'Tiger hair fiberglass resin".  The exterior of the coil received
> > three coats of said poly and was then wound with #18 super motor
> > wire from the local motor shop, it was some kind of isopolyidamide
> > or something motor winding wire and it was the best that there is to
> > be had.  The form was close wound for the first 22" and was then
> > spiraled loosely for the last three turns to reach the top of the
> > form.  I guess about six pounds of wire on the form.  It was then
> > coated with said poly coating until the winding was smooth and free
> > of gaps.  I guess about 6 or seven coats of poly.    Ground wire to
> backyard
> > spring:  1/4"od refrigeration tube layed next to a #4 aluminum THW
> > single cable, both terminating in a 1/2" hard copper tube driven
> > into the loose moist clay of a year round natural spring. Primary:
> > Flat, 3/8"od copper tube. 14 turns total, 5/16 max. between
> > turns.  Tuning: variable, dependant upon the use and type of
> > topload, if any.  Tuning can give the same spark length regardless
> > of the size, construction, shape, or composition of the topload.
> > Distance, inner turn of primary to secondary: slightly more than 1".
> >  Length of arc in free air: six to seven feet, and approaching eight
> > feet dependant upon weather. Spark length to grounded object:  four
> > to six feet.  Also, please note: this coil can give the same results
> > if or if not connected to a ground poise for the secondary bottom
> > terminal.    So, what is the verdict?    Al.
> >
> > On Tue, 22 May 2001 18:18:32 -0700 Scott.L.Hanson-at-seagate-dot-com
> > writes:
> > > There is nothing in your power supply or tank circuit that is out
> > of
> > > the
> > > ordinary, or would seem to have any affect on the secondary. I
> > > suspect that
> > > the self-capacitance of your secondary may be providing the
> > largest
> > > effect.
> > >
> > > Could you define the following characteristics:
> > >
> > >      Secondary:
> > >           Form dimensions (wound length, diameter, wall
> > thickness)
> > >           Form material (including any coatings)
> > >           Winding data (wire diameter, wire type [magnet wire,
> > PVC
> > > insulated hookup wire, Kynar insulated wire-wrap wire, etc],
> > > insulation
> > > type & thickness, close wound or space wound, overcoating,
> >
> > > single
> > > wire or multiple wires paralleled)
> > >           Total number of turns (if space wound)
> > >           Height of first turn relative to primary
> > >           Grounding (ground wire diameter and length, define
> > > connection to
> > > "backyard spring")
> > >
> > >      Primary:
> > >           Type (helical, conical, flat, or ??)
> > >           Conductor type
> > >           Number of turns used at best tune point
> > >           Spacing of turns (center-to-center)
> > >           Distance from inner turn to surface of secondary
> > >
> > >
> > >      Typical arc length:
> > >           Streamers to free air
> > >           Arc length to grounded conductor
> > >
> > >
> > > Have you measured the primary/secondary coupling factor?
> > >
> > > Do you have an oscilloscope available to monitor the ringdown?
> > >
> > >
> > > Many older (turn-of-the-century) Tesla coils were  built with only
> > a
> > > small
> > > discharge ball at the top of the secondary and performed well. The
> >
> > > addition
> > > of a large capacitive top load  has become common over the last 20
> >
> > > years or
> > > so as a better understanding of Tesla coil operation has been
> > > gained.
> > > Regardless of how well your coil seems to operate now, I am quite
> >
> > > sure that
> > > I will perform better if supplied with a topload, and re-tuned to
> >
> > > optimize
> > > with the larger top capacitance.
> > >
> > > Regards,
> > > Scott
> > >
> > >
> > >
> ________________________________________________________________
> GET INTERNET ACCESS FROM JUNO!
> Juno offers FREE or PREMIUM Internet access for less!
> Join Juno today!  For your FREE software, visit:
> http://dl.www.juno-dot-com/get/tagj.