Re: Secondary runners

["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>

Dear ???
         I do believe it is "coupling", not cupping.  See below.

On 24 Sep 2001, at 17:49, Tesla list wrote:

> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<Robynsaddiction-at-aol-dot-com>
> 
> Hi List, 
> 
>       What besides cupping can cause arcs to race down my secondary. It is
> happening with one of my smaller coils (1.75 inch by 10 inch winding length).
> The coil form is acrylic tube, and the bottom turn of the secondary is even
> with the bottom turn of primary. The primary is a 30 degree cone type
primary,
> with 9 total turns at .5 inches apart. Torrid is 3 inch by 8 inches OD,
and my
> capacitors are TDK UHV series Strontium Titanate pulse rated capacitors. The
> cap bank is right at .01uF, and that is perfect for my 9/30. All I can
seem to
> get out of the coil is 12 inch arcs, and with those I get runners. Perhaps it
> is because of my single static non-quenched gap that I am using until I have
> time to make a better one. What do you think?

You can try raising the secondary up a bit to reduce the coupling. 
Your primary energy is probably borderline for a 10" winding length - 
in other words, your output voltage is too high for the length of 
your coil.

Malcolm