Re: spark gap muffler? -> More tuning questions.

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

Original poster: "Bill Vanyo by way of Terry Fritz <twftesla-at-qwest-dot-net>" <vanyo-at-echoes-dot-net>

OK, there seems to be a unanimous consensus - if the gap is louder than
the streamers, something's wrong.  Well then, something's wrong.

I *am* still in the process of tuning it, and don't get to run it often
- I can only run outdoors, and it's been windy lately - I'm waiting for
a still night to try again.

Could it be that my cap is too large, even for LTR?  I'm using 0.06uF
with three 15/60 NST's, whereas 0.045uF would be about right.  How
significant is this?

If I can get my hands on another 15/60, I'll throw it on, but in the
meantime...

Also, my spark gap is adjustable, but I'm thinking maybe I don't
understand the principle behind how to adjust it.  Basically, what
effect does having the gap wide versus narrow have?  I've noticed that
when it's wide, it seems to fire more erratically.  If the gap is set
too narrow, how does that affact streamer length?

Is there anything else I should look at?  I got sparks about 2 feet max
in a good breeze.  Was it just the breeze, or is something else way off?

	Thanks,
	Bill V.



BTW, the specs again are:

Power Supply: Three 15/60 NST's, with Terry's protection filter on the
high voltage side, and redundant line filters and a 50 amp variac on the
120V side.

Capacitor: A Maxwell 30 kV, 0.06 uF cap (model # 37321).

Static Spark Gap:  9 copper pipes mounted in a blower box, with
adjustable spacing.

Secondary: 1000 turns of 22 awg, 6.5" (closer to 6 5/8) diameter, 27.5"
winding length.  Countless coats of polyurethane.

Primary (just rebuilt): Flat spiral, 10 turns of 1/4" copper tube, 1/2"
spacing on
centers.  Inside diameter 9.5".  Tapped between 6 and 7 turns.

Toroid: Aluminum dryer duct, 8 inch cord with 24 inch center to center
spacing.

Ground: 32" segment of copper clad iron ground rod.

All interconnects are 1/4" copper tubing, with 1/16" thick polyethylene
insulation (3/8" o.d., 1/4" i.d. tubing), except I use welders cable to
my primary tap clip (both heavy and very flexible),
and 15kv rated high voltage wire from the power supply to either side of
the spark gap.

Misc: Strike rail (open loop).


Tesla list wrote:
> 
> Original poster: "Barton B. Anderson by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <tesla123-at-pacbell-dot-net>
> 
> Hi John, Bill,
> 
> Just to add to John's post regarding gap noise and spark noise (I'll be
brief):
> 
> When I first built my coil, the gap made most of the noise. As changes were
> made
> and knowledge was being soaked in and applied, the coil began running more
> efficient including longer sparks. One day I noticed the spark was the main
> sourse
> of noise. If the gap is making most of the noise, then the coil is not
> getting the
> power to the spark and it is being lost elsewhere.
> 
> Bart A.
> 
> Tesla list wrote:
> 
> > Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <FutureT-at-aol-dot-com>
> >
> > In a message dated 5/24/01 10:31:10 AM Eastern Daylight Time,
> > tesla-at-pupman-dot-com writes:
> >
> > > Has anyone invented such a thing?
> > >
> > >  Basically, I'm wondering if there's any way to make a silent or somewhat
> > >  quiet spark gap for a medium to high power coil.  I'm currently using a
> > >  static gap, but would consider other designs.
> > >
> > >   - Bill V.
> >
> > Bill,
> >
> > There exists so called true static quench gaps that are quiet, because
> > the sparking chambers are sealed.  But most of the noise from
> > a Tesla coil is from the output spark streamers anyway.  What
> > real benefit would be gained by quieting the gap?  The overall
> > coil would still be very loud.
> >
> > John Freau