Using guts from BTC-3

Subject:  Using guts from BTC-3
  Date:   Thu, 24 Apr 1997 09:40:42 -0400 (EDT)
  From:   tesla-at-america-dot-com (Bob Schumann)
    To:   tesla-at-pupman-dot-com
    CC:   USA-TESLA-at-list.usa-dot-net

Howdy coilers,
        Like some coilers, my first TC was the BTC-3 from Information
Unlimited. It wasn't unitl I got on the Tesla lists that I discovered
how poor design the kit was. The primary setup was funky because it
had a number of turns of PVC covered stranded wire bunched together
and soldered to a 3 turn solid piece of wire where tuning occured.
I am sure the bunched coated wire was just there to provide enough
inductance to bring the system close to tune. The kit was an okay
learning experience but I found almost every aspect and component 
lacking good efficiency. When I changed all the components, I actually
ended up with a totally new coil from scratch that used absolutely
no parts from the kit! 2 components from the kit are acceptable keepers.
The 6kv-at-23ma open core transformer and the .005uf -at- 6kv capacitor.
The secondary is toast as it has an internal grooved arc highway
due to the fact that they (Information Unlimited) drilled holes in the
side of the form. My end thought is that Inforamtion Unlimited wanted
maximum money for the kit with minimum money spent for parts.

I want to take the lonesome transformer and cap and make a small
table top coil I can take with me to show people. 

I have everything worked out in my mind except for one aspect.
Because the power output from this transformer is low, I will
choose the inverted cone primary. I know for surface area that
it is good to use the copper tubing but I really don't want to
make this system big and am thinking of a samller primary than
using copper tubing, even the 3/16" stuff.

[snip here]


Do you think it is possible to get good results with this
small system if I use the bare copper wire that is sold
for ground connections to circuit breaker boxes?

I know it is not tubing and that its surface area is smaller
and a waste that it is solid, but it seems to me that I can
have a much physically smaller primary.

One recourse: I can use the copper tubing and just have say
4 turns, make my primary first, and wind the secondary to
be within tuning range.


Bob Schumann