Re: LTR problems

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

Original poster: "Malcolm Watts by way of Terry Fritz <twftesla-at-qwest-dot-net>" <m.j.watts-at-massey.ac.nz>

Hi Robert,
           There are two alternatives you can try, one better than 
the other:

On 29 Oct 2001, at 15:55, Tesla list wrote:

> Original poster: "Robert by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<obiwan1186-at-sunflower-dot-com>
> 
> in anticipation of the trigger gap i'm working on, I tried tuning my 
> coil running on LTR (I assume ltr is 1.5X resonant). basically 
> performance was terrible. it tuned at about one turn and i was getting 
> about 12" sparks and that's it (i'm running at 9/150). my res frequency 
> is about 250KHZ. is there anything i can do or do i have to just give up 
> the idea of running with the metlicka trigger gap? By the way, i just 
> got my geek caps, and when i hooked them up at 15nf they worked great! 
> my spark lenght increased by 50%! If you are thinking about going to 
> mmc, definately go with geek caps. they didn't even get warm after ten 
> minutes of run time!

With a power supply like that you should be looking at an output 
around 4 - 5 feet.  

#1 - your primary is obviously losing a lot of power. Throw away your 
secondary and build one which resonates at a much lower frequency so 
you can use a decent amount of inductance in the primary.

#2 - you can wind a third coil the same diameter as the primary and 
mount it an inch or so above the primary. This coil should have 
considerably more inductance and use a much lower resonating 
capacitance than the primary. Catch is, the resonating capacitor for 
the third coil has to be rated for voltages in the 100kV range. (I 
actually did this on my first mains coil and use a transmitter 
ceramic as the resonating cap. It boosted the Q of the driving 
circuits and greatly increased the coupling - until the cap died. I 
still went from 20" to 4'+ by throwing the old coil away and building 
a decent one using the same transformer and primary cap).  

Option #1 is the preferred route to take.

Regards,
malcolm