Re: Some pictures of my coil ( finally working )

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

Original poster: "Barton B. Anderson by way of Terry Fritz <teslalist-at-qwest-dot-net>" <tesla123-at-pacbell-dot-net>

Hi Christoph,

Glad to hear you rid your coil of the unwanted arcs. The pictures really 
help get a better idea of your coil. Just for giggles, I went ahead made 
the input corrections where I could find them (toroid height, 35 deg. cone 
plus repositioning, strike ring, etc..) and put all  that back into Fantc 
again. Fres settles in at 264 kHz which is still much higher than the 
measured 180kHz or so. Anyhow, tuning should be at 9.7 turns (say 10). 
Also, coupling is 0.108 via Fantc again. I would suggest adjusting coupling 
a little higher, but looking at the coils mounting, I don't think it's 
possible without reworking something. Not a big deal. Where it is, it will 
probably run all day that way. One thing, with the toroid height relatively 
high above the top turn of the secondary, you will get corona and possible 
arcing off the top of the secondary winding, so keep an eye on that.

If you do adjust coupling at some point, you will probably need to lower 
the toroid. The toroid height adjustment on your coil will make little 
difference in Fres (maybe 0.3 of one turn). A lot of times when adjusting 
coupling, we adjust until we get racing sparks then decrease it until we 
can run at full power without the racing sparks down the secondary (note, I 
left out several details in that statement). Anyway, the racing sparks tend 
to start at the top winding of the secondary. If the toroid is doing a 
lousy job at shielding the sec top windings, then racing sparks will occur 
sooner than later. It's at least my opinion the toroid height should be 
adjusted along-side coupling adjustments when optimum performance is the 
goal (vs. for measurement, research, etc..).

Good job with your coil and thanks for putting up some pics. Always love to 
see pictures.

Take care,
Bart

Tesla list wrote:

>Original poster: "Christoph Bohr by way of Terry Fritz 
><teslalist-at-qwest-dot-net>" <cb-at-luebke-lands.de>
>
>Hello everybody!
>
>Last week I came up with some questions concerning my tesla-projekt.
>After many good advices from several people I was able to achieve better 
>results.
>Althoug these pics must sem boring to you as you see much nicer sparcs 
>most of the time, I couldn't help putting them on the web. And here they are:
>
><http://www.luebke-lands.de/tesla.html>http://www.luebke-lands.de/tesla.html
>
>The most efficient thing was to get rid of the two RF-Chokes. That stopped 
>the mysterious lightning at the grounding point and the lack of output-power.
>
>Thanks again to everyone who helped me with suggestions.
>
>greetings
>Christoph Bohr
>
>