do you have pics of you coil asian cow?

Ok, our tesla coil is still not working and I have stopped working on it for now. But to answer your question, yes, the spark gap is emitting a very loud and blue spark in the spark gap but absolutley nothing is coming from the top load. We used 1/4 inch copper tubing for our primary.

Ok I have visited deepfriedneon.com but they only give informtaion on helix and flat primarys (or at least thats all I could find). The capacitors work. They create a much louder and brighter spark when hooked up to the spark gap then with just the transformer. We have also tried taking off the top load and placing a metal rod next to it but as you can see, even in the dark no spark is visible. 

Did you ever get this coil working? I just built a spark gap tesla coil running on a 9kv transformer myself, and could probably help troubleshoot.

I know why. your caps use water bottles right? they don't have a very high voltage rating and will work very badly. So just spend $15 and get a real cap and your tesla coil will work great.

isnt it possible to make a tesla coil for any frequency?

im trying to work through a book to figure out how to get a coil with a resonant frequency of around 7. 85hz. It would be interesting to

1, get a coil to resonate at this frequency, and 2, drive it with a modulated signal and see if you can get a second tesla coil to pick up the signal by 1 of 2 ways... 

1, just passivley picking it up and amplifying it.
2, On the second tesla coil, putting a loosely coupled inverted signal on the antenna which makes the electric field vectors add together (cause if you blow a ball from a super powerfull vaccume in my direction and i use a vaccume to suck the air around me in, the ball will drift my way)

If they are in resonance i believe that it will make an electrostatic circuit, if you increase the frequency then the air becomes like a dielectric, whos resistance to power flow is reduced as the frequency increases.

this could be seen as a form of quantum tunneling i guess.... i feel there are more classical theory explinations.

anyways, im poor and going through school at the moment, so unless i get a grant, or hit the lottery i wont be able to test these things till some ones allready tested and invented the darn thing so... lol...

anyways i was just wondering what you thought, or have tried with the coil.

lol... no 7.85 hz very long wave. At that frequency, theres an electric field that engulves the earth in a resonant mode thats some what like what happens when a jump rope is swung up and down in it's first resonant mode (the antinode basically engulves the earth. I think it would allow a piece of circuitry in the earth to link electrostatically with the earth's electric characteristics.

a 7.85 hz teslla would be around 900 feet tall!!!!!!!!!!!!!!!!!!!

sorry
http://www.youtube.com/watch?v=5Td--HItuoI
kinda like this?

http://www.youtube.com/watch?v=5Td--HItuoI kinda like this...

and as for high frequency..... think resonant vibrations with atoms and molecules rather than electromagnetism coupled with no mass.... so something in the terrahertz range or higher?

ps. i forgot to mention the 2 modes (at one point i say low frequency and at another i say high).... i think a high frequency coil would be good to transfer power between two oscillating coils, but low frequency would be the way to get energy thats injected into the earth's upper atmosphere by solar winds etc.

also ps.

your coils and experiments are beautifully done, setup , and displayed!
i love your designs!

First, doing so would inhibit resonance.

Second, doing so would make the circuitry heat up, due to increased average current pull.

Third, if hooked to a Tesla coil, a function generator would die.

What mean more is using the coil as an antenna. (the primary transforming the signal to a highvoltage secondary).

I've been reading a tesla coil building "guide" and i find it very interesting that these are not used more often for radio broadcast. These oscillators should be incredibly efficient , though its best operation may not be producing photons (EM couplings).

While they may work fairly well for Radio Broadcast, they don't work well for FCC-licensed radio transmission, unless you use a solid-state or vacuum tube Tesla coil (fixed-frequency oscillators). The reason for this is that a spark gap Tesla coil emits noise on a great number of frequencies, whereas the other two mentioned are fixed to a specific resonant frequency. FM (Frequency Modulation) is all that is easily done with a Tesla coil, though the modulation circuitry to have its output be a crisp voice is quite complex.

The Tesla coil is also, as you have mentioned, much more efficient at radio transmission when it is not 'breaking out,' or when no streamers are present. This is in itself an issue, since the state in which a Tesla coil does not break out is very hard on its driver circuitry due to the energy in the primary circuit 'ringing' for far too long, since it is unable to transfer quickly to the secondary. If this happens, the secondary will attempt to pick the energy up frm the primary and feed energy back into the primary at certain points, causing very large voltage spikes in your primary circuitry, likely damaging your delicate circuitry, such as transistors and diodes.

In short, while the principle is sound, the practical application is more difficult than it is worth.

Note: Tesla himself thought of the idea of transmitting pictures and music over a Tesla coil's output.

I agree the engineering gets a bit difficult.

about the ringing for too long.. isnt that a tuning issue? And the two coils should be loosely air coupled to allow for a kind of slip.

as for the switching device i agree.. but it depends on what switching device you use. Tesla used a rotary gap where the electrodes in the drum would periodically be connected by mercury that stayed in the bottom as the electrodes rotated around. As i understand this improved operations...

but anyways... probably more money than its worth....

If you have enough.

I am going to make glass plate caps they have a much higher capacitance than beer bottle caps I measured one at only 0.64pF.

Actually they are 20 oz

Ok, I don't have a way to test them, but I am planing on making about twenty plastic bottle caps. I know it is done with 2L ones, but would you mind testing to see how good a little 22oz one would be. I also may try using 1 gallon tubs of icecream.

It wouldn't be any better maybe worse. The best way to make home made high voltage capacitors are with glass plates. If you do be sure to make the glass thicker than necessary so it can suffer voltage spikes. Here's a good site.

I know they wouldn't be very good, but I don't have access to glass plates, I basically need a way to make a bunch of really cheap capacitors, and I don't drink beer, wine, or snapple

If you have a lot of PVC buckets around you can stack them up with aluminium tape or al foil. You can use the plastic bottle idea but to get the average Tesla coil tank capacitor capacitance you'll need a lot I think.

Somewhere I remember something about layering paper and al foil, would that work.

Only for low voltage stuff.