Re: First Light for 10" Coil.

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

Original poster: tesla <tesla-at-paradise-dot-net.nz> 

Greetings Peter

A most interesting coil and quite similar to my own

Very interested in the way you have done things

The differences
Mine has 90nF of the 1600v 0.33uF caps (like Robin Copini)
SRSG is currently 300bps and all electrodes are near the 90deg and 270deg
points. This needs fixing, How did you decide on the location for your
rotating electrodes to set timing

I use PFC of over 100uF and up to 6 MOT's. The MOTs I have are in oil and
phased about ground. I use 900watt xfrmrs. I run fixed ballasting of 22mHy.
I was intrigued by your ballast and would be interested in the short form
specs on that.

I have just purchased the bits to put a dedicated outlet at the house so
should be able to run the thing flat out.

My operating freq, toroids and so forth are pretty similar, I can maker the
beast do 2 metre O/P but I know it will do better when I get SRSG timing
better and a dedicated mains. It will run > than 40amps if I let it so need
to keep it at that level or things start to go wrong, like fuses start to
blow.

Hope to hear more from your expts

Rgds
Ted L in NZ
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Wednesday, December 24, 2003 8:54 AM
Subject: First Light for 10" Coil.


 > Original poster: "Peter Reid" <peter-at-reidconsulting-dot-com.au>
 >
 > Hello Everyone on the Tesla Coil Mailing List.
 >
 > I have just finished building my new MOT powered 10" Coil and managed to
 > tune it somewhat. I am quite happy with the results so far, however I am
 > wondering if anybody could shed some light onto areas I should work on In
 > order to improve the spark length and power handling capabilities of this
 > coil. So far I have managed occasional 8.5ft Power Arcs to a grounded rod.
 > However I feel that the coil is still capable of a lot more. Initially the
 > spark output was quite poor until I increased the coupling between the
 > primary and secondary. (I don't think I've gone too far).
 >
 > I will list the specifications below. With the current setup I am getting
 > quite powerful arcs to the strike rail and ground with-in about a 3ft
 > radius around the coil.
 >
 > I have posted some photos on my website for anyone that's interested. I
 > also have some pretty good video footage, but that isn't on the
 > webpage.
 > <http://tesla.reidconsulting-dot-com.au/>http://tesla.reidconsulting-dot-com.au
 > Any input / help with improving the current setup would be greatly
 > appreciated, I am just a little worried about burning up my secondary if I
 > try and pump any more power though it.
 >
 >
 >
 > Coil Specs are as follows..
 >
 > Primary
 > Flat Spiral, Wound with ½ In Copper tubing, spaced but ½ inch.
 > ID = 12.7in
 > OD = 32.5in
 > Turns = 10.25, tapped at about turn 6.15
 > Primary sits 1.5ft above the ground on a specially made wooden platform.
 > Strike Rail = 1/2copper tube raised by ½ inch around outside of primary.
 >
 > Secondary
 > Wound on a 10" PVC pipe, which has been baked and sealed with many coats
of
 > polyurethane.
 > Winding length = 41in
 > Wire Diameter = 0.9mm B&S Gauge 19
 > The bottom turn of the secondary is elevated 1 inch above the top of the
 > primary winding.
 >
 > Toroid
 > 12" x 42.5" (Tube Diameter x Outside Diameter of Toroid)
 > Mounted 12in above the top winding on the secondary.
 >
 > Measured Res Frequency of Secondary is 84.8kHz, and primary has been tuned
 > to exactly that. (Can someone please tell me if its worth trying to detune
 > it by 1/3 of a turn to account for streamer loading etc?.)
 >
 > Capacitor
 >              0.15uF MMC Cap Bank made up of 144, 942C20P15K caps.
 >
 > Power Supply
 >              6 MOT Supply, Currently Ballasted to 40A -at- 240V (Using a
 > Sliding Choke Balast)
 >              Maximum line draw current of 80A -at- 220v when the ballast is
 > removed. That's 17.6kVA J
 >              Approx 12kV output.
 >
 > Spark Gap.
 >              200bps Sync Gap, with a Remote Phase Adjuster.
 >              Single Gap, Tungsten static electrodes, and 4 x 8mm brass
 > threaded rod (moving electrodes) Spinning on a 12in
 > G-10 disc (3000 rpm) Gap spacing is about 1-2mm total.
 >
 >
 > BTW, Thanks to everybody who has contributed to the mailing list, the help
 > I have received from you guys has been invaluable.
 >
 >
 > Regards
 >
 > Peter Reid.
 >
 >
 >