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Re: Magnifier system

Tesla List wrote:

Malcolm,

> 
> >From MALCOLM-at-directorate.wnp.ac.nzWed Nov 20 22:13:44 1996
> Date: Thu, 21 Nov 1996 08:23:48 +1200
> From: Malcolm Watts <MALCOLM-at-directorate.wnp.ac.nz>
> To: tesla-at-pupman-dot-com
> Subject: Re: Magnifier system
> 
> Hi Dan,
>           In reply....
> 
> >     First, whenever I'm determining the resonate frequency of a secondary I
> > personally use
> > the grid dip method. Attach an "O" scope and RF frequency generator to
> > the base with dischard
> > terminal attached (serial). Simply raise the frequency until the coil
> > starts to draw max current.
> 
> Different method from mine but just as good. Might not be the best way
> of measuring unloaded Q though.

Your probably right.

> 
> >     Second, I'll use the same setup to tune my primary to the secondary by
> > using a parrell
> > setup and <SHORTING> my spark. Then keeping my RF generator at the
> > resonate frequency, I'll adjust
> > my primary tap until my primary draws minimal current. There by, both
> > circuits are in tune.
> 
> I wonder about that. The resonator should be heavily absorbing when
> correctly tuned to the primary shouldn't it? I prefer to tune the
> primary to the secondary with no secondary present to get scope tune.
> Or is that what you're doing (measuring parallel resonance)?

Yes, Its parallel resonance.

> 
> > And now the fly lands in the ointment!
> >
> > In the obove paragraph I stated that the spark gap was shorted,
> > there by I was able to obtain an LC oscillator with a frequency that
> > will cause my secondary to resonate. But in operation, the circuit
> > used is a Spark Inductor Capacitor variety. Spark gap circuits,
> > also known as dampened wave oscillators, output multple RF
> > frequencies while in operation. From this understanding come some
> > questions that need to be asked.
> >
> > a) How much wave dampening do these secondary frequency impose on the
> > secondary, as its being excited
> >    by the primary?
> 
> Virtually none, because the secondary being highly selective forces
> unwanted frequencies to remain in the tank and the energy in them
> ends up contributing to the fundamental.
> 
> > b) Would simply dividing the secondary into two parts reduce the above
> > effects?
> >
> >     The base being few but large AWG(9) turns for capturing as much
> > magenetic energy as possible and reducing the out of phase effects of
> > the primary. Top comprising many turns of small AWG(30)
> > wire, to take advantage of the voltage rise due to inductance. And of
> > course the split secondary's
> > top part would have to be seperated by a distance that reduces the
> > primary circuits influence. Therefore,
> > the magnifier could be an attempt to minimize the amount of cross noise
> > in a tuned resonate circuit.
> 
> To me the thing about transformer coupling to the base of the
> resonator should eliminate the frequency split one normally gets with
> DTC (over)coupling (I will be checking this soon). I think other
> spurious resonances generated by the primary decrement alone are (a)
> pretty insignificant in amplitude compared with the fundamental, and
> (b) are effectively squished by the selectivity of the
> secondary/tertiary.
> 
> Malcolm

I agree with (a) that they secondary frequency's are insignificant in 
amplitude when compared with the fundamental but I'm not so sure about
(b). The past few weeks I've been conducting some experiments, capturing
wave forms on my dual trace "o" scope. 

	My setup. First, I placed a vertical grounded rod 2 1/2 feet from
the toriod of my coil. At 2 1/2 feet this is a consistant strike point.

Note: My system uses 6 6' steel copper jacketed ground rods placed out
      in my rain water saturated yard.

	Second, I attached a 1 megaohm resister to the vertical ground. with
two 40KV "O" probes attached to the scope. And one attached to the 1 meg
resister and the other attached to my primary circuit respectively.
	Last, I attached the trigger connector to the 1 meg resister using
a resister network. And a 35mm camera attachment was placed on my old
"o" 
scope, with a 35mm camera and autowinder. (I should receive the pictures
back
next week.)

	The idea simply being when the Tesla coil discharges and strikes
the ground rod it will trigger the scope and I'll get a real time image
of what is going on. And yes, it does work. According to my eye there
are
some parasitic frequency's that are transfered. And some of the
harmonics
seam to be 180 out of phase. Understand the amplitude of these are very
low. But one would have to wonder how much quantum efficiency was robbed
by these little parasites?

Note: I'm running my "o" scope on a APC 600 UPS that I disconnected from
      the 120 AC circuitry in my house. There should be no parasites
from 
      that source. 

(Sorry Chip for rattling on.)

Another note: Should receive my coil pictures friday night. And will
              post those next week.

Tesla coiler at large.
D. Gowin