[TCML] Refurbished Coill

[Barton B. Anderson]

Hi Ruben,

I ran Javatc on your coil specs.

http://www.classictesla.com/temp/rubenpeters.txt

With the primary even with the bottom of the secondary, coupling is .122 
and a good value (Javatc recommends .123 on this coil). Javatc has the 
ability to accurately account the toroid capacitance and it's affect on 
the coil overall, so the resonant frequency showed 449 kHz when all is 
said and done for a primary tune at 7.75 turns using .0111uF. The cap 
value is good.

The primary to secondary clearance is close and could be problematic. 
You might want to start the primary at 25mm distance to be safe. Javatc 
recommended 1.2". The toroid size looks good for the coil size. You 
might get away with a little larger radius, but difficult to say.

Take care,
Bart

Ruben Peters wrote:
> Hello All,
>
> I've recently re-joined the list, and am getting back into coiling after a 3
> year hiatus, anyway, I'm aiming to refurbish my first coil-to be sturdier
> (initially a hot glue and tape job), and a better performer (originally
> around 9" sparks with  9.2nf wine bottle caps, and what I think was over
> coupling due to the occasional racing spark and the 40 degree, 7 turn
> conical primary).
>
>  
>
> I plan to use my original secondary coil, and 12/30 NST, with a new MMC and
> flat primary setup.
>
> For the spark gap, either a Multi-segment static gap, or I'll try out some
> gas surge arrestors (Im aiming for a bit of noise suppression)
>
>  
>
>  The Planned specs are:
>
>  
>
> Transformer/Cap:
>
>  
>
> 12/30 NST
>
> 11.1 nf LTR Cap
>
>  
>
> Primary (wintesla 5 and Tesla Coil CAD 2) :
>
>  
>
> Primary capacitance : 0.0111uF
>
> Primary resonant frequency : 428.89kHz
>
> Primary conductor diameter : 0.25in,6.35mm
>
> Primary turn to turn spacing : 0.25in, 6.35mm
>
> Spacing between the secondary and the inside turn of the primary : 0.59in,
> 15.00mm
>
> The primary will need to be tapped between turn 8 and turn 9 to form a
> resonant circuit at 428.89kHz
>
>  
>
> Inside Diameter: 3.346in 85mm
>
> Total Primary Diameter: 16.35in, 415.29cm
>
> Length 32.66ft, 10m
>
> (This gives 13 turns total with the aim of re-using the primary for the
> inevitable next coil)
>
>  
>
> Secondary: 
>
> Secondary Wire Diameter (IN) 0.0113, Wire Gauge 29.0000   
>
> Secondary Coil Total Outside Diameter (IN) 2.1650  , 55mm
>
> Length of Secondary Coil (IN) 10.5000  , 265mm
>
> Secondary Turns/Inch 86.1508
>
> TOTAL TURNS : 878  
>
>  
>
> Secondary Coil Calculations (wintesla 5):
>
>  
>
> Inductance (mH) 7.86  
>
> Medhurst K  0.78  
>
> Radius (IN) 1.08  
>
> Circumference (IN) 6.80  
>
> Wire Length (FT) 497.33  
>
> Self-Capacitance (pF) 4.31  
>
> Secondary Frequency (kHZ) 865.00  
>
> Secondary Frequency W/Terminal C (kHZ) 428.89  
>
>  
>
> Toroid:
>
>  
>
> Top Load Capacitance (PF) 13.26pf approx
>
> Sphere Radius/Toroid Tube Diameter (IN) 2.5000  ,63mm
>
> Toroid Diameter Tube Center-to-Center (IN) 10.0000 ,254mm
>
>  
>
> Of course I have a few questions, so any help/suggestions on the above are
> very much appreciated.
>
>  
>
> 1)      Will the 15mm clearance between primary and secondary base be
> sufficient (the winding starts around 2cm up the secondary)?
>
> 2)       Any advise on coupling for this system (the notion that my previous
> setup was over coupled is just a hunch, backed by the occasional racing
> spark)?
>
> 3)      Am in in the ballpark for an optimum torroid size?
>
> 4)       Finally, does anyone know a good MMC source in Australia?
>
>  
>
>  
>
> Thanks again for any input
>
>  
>
> Ruben
>
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