Re: Please Advise

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

Original poster: Bart Anderson <classi6-at-classictesla-dot-com> 

Hi Emmett,

Tesla list wrote:

>Original poster: "Emmett Secrest" <secrest2032-at-msn-dot-com>
>Hi Bart,
>
>Thanks for the encouragement and advice from you and Gary.  As you know I 
>am new to this and this is my first coil. I feel I have been very 
>fortunate to have achieved the results I have so easily.  Not that I 
>haven't had any bugs to work out. What success I have had I owe to the 
>people on this list.  I am on my own on this as there aren't any coilers 
>anywhere near me, that I know of.

Yep, probably true for a lot of us. Kind of lonely hobby, but then I'm that 
way naturally <grin>.

>I was getting good streamers from just the one NST then added the second 
>one. I was getting longer streamers with the second NST but they were 
>coming in such rapid succession that I felt I was not gaining the increase 
>in streamer length that I should have gotten.
>This made me think that I maybe needed a bigger Toroid due to the 
>frequency of the streamers.  I haven't decided on the 24" or 30" diameter 
>yet but will be getting the 6" dryer duct tomorrow.

30" would be a goodly sized OD. Should you try that out, I'd recommend a 
center disc to aid shielding (as the OD gets further away from the coil, 
the less shielding for the stress at the top of the secondary). Al tape can 
be used over the toroid and disc and helps smooth out the corrugated tubing 
(kind of spendy tape however).

>I am really anxious to see what effect it has on the output.  I had 
>expected to get racing sparks down my secondary but have not had that 
>problem at all.

Nope, I wouldn't expect you to. Your coupling is pretty low around 0.109 
(from memory). You could actually increase the coupling and increase 
performance in the process. But even at this loose coupling value, your 
coil is doing very well.

>I did get better performance at the 4th turn instead of the 5th but was 
>getting so many streamers and strikes to the strike rail that I backed it 
>out to the 5th just to tone it down some.

Ah, that works out now. The 0.25" spacing is then a good value. Hopefully 
the new toroid will help with field control (where those sparks are going). 
I ran a similar coil last night to bring in the new year (4.5" x 20.165"). 
The sparks typically stay horizontal, although I did get one strike last 
night to the primary (near the grounded end). I'm running 8.5 turns with a 
0.025uF Geek MMC bank (similar primary (.25, .25)) but with only an inch 
between pri & sec. Ah, similar toroid as well (4.5" x 19.25"). It also 
needs a bigger toroid.

>I had already experienced my first strike to the primary and did not want 
>to see that again. Nothing was damaged but I wasn't sure I would be so 
>lucky the next time.  I changed the position of my strike rail and it 
>seems to have solved the primary strike problem. I will post the results 
>of the Toroid change.

It will happen from time to time. Worry if becomes frequent.

Take care,
Bart