Re: primary coil material / design

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: BunnyKiller <bunnikillr@xxxxxxx>

Hey John..

nice idea but here are the issues,

1. the insulation is usually rated for 600 V and 2KV+ will arc thru 
it in a heartbeat.. thus shorting the primary
2. tuning the primary would be at best cumbersome, you would have to 
peirce the insulation to get to the wire inside,
    thus leading back to problem #1.

the reason why we use soft copper tubing is that is mostly self 
supporting between the standoffs,  it can be spaced between winds to allow for
"insulation" reasons, allows easy tapping/tuning,   and if you take 
your time with the tubing ,it really isnt that hard to form it into a 
coil. Leave it in its coiled form as it comes in the box and 
"re-arrainge" the tubing to fit the supports. Bending soft copper 
tubing causes the tubing to "harden" ( its called work hardening) 
which ends up with that section of tube that you never seem to be 
able to get into that perfect arc  :) .....

Scot D



Tesla list wrote:

> Original poster: John <guipenguin@xxxxxxxxx>
>
> Hello I am in the middle of building my first coil. I am going to be 
> using a 4" diameter for the increased inductance.
>
> I see everyone uses copper refrigerator tubing.... but is there any 
> reason (Besides being hard to tune!) to use something like this: 
> <http://img82.imageshack.us/my.php?image=dcfc0002ud6.jpg>http://img82.imageshack.us/my.php?image=dcfc0002ud6.jpg 
>
>
> I made that test coil just for this email, it isn't enough turns, 
> but its just for demo. Why would this be a bad choice?
>
>
> Thanks,
>
>      John.