On 3/25/15 7:52 AM, Timothy Gilmore wrote:
The secondary bottom will go to electrical house ground.
Uhh.. not necessarily. Yes, it should eventually connect to electrical safety ground (aka green wire or third prong ground), but you do not want to use that as your only RF ground.
Even a small coil (especially a small coil, which will have a higher operating frequency) should have a counterpoise or good ground *plane* under it.
If a larger sized
coil is made - it will go to both electrical ground and RF ground (made with a 4-8 copper pipe in the earth or large sections of Hardware cloth/Chicken wire directly placed under the tesla coil - ensuring its considerably larger than the top load).
I'm not a big fan of ground rods. They're not a particularly good connection to "ground".
I am a fan of a screen counterpoise. Hardware cloth, chicken wire, aviary netting, reinforcing mesh, sheets of aluminum foil, etc. Radius of counterpoise should be comparable to the height of the topload above the mesh.
So if you have a table top coil that's 2'-3' tall, you'd have something like a 4 foot diameter or square conductive plane under the coil on the table top.
If you have a 5 foot secondary on top of a 3 foot high equipment cabinet with your rotary gap, etc., so the topload is 8-9 feet high, then you want a 20 foot diameter counterpoise.
another alternative is a fence or cage around the coil, connected to the bottom of the secondary.
The secondary top "should" go to a top load of either a sphere for smaller distributed multiple sparks or to a donut shaped toroid which provides some additional minimal capacitance and will allow build up of sparks to be longer in length. Tim On Wed, Mar 25, 2015 at 8:01 AM, Doug <doug11642@xxxxxxxxxxx> wrote:Gentlemen; I am building my first Tesla Coin rated at around 250.000 volts and would like some advice on routing and connecting the secondary coil wires top and bottom. Thank you for any help you can provide. Doug Johnson _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla_______________________________________________ Tesla mailing list Tesla@xxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla
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