Re: Looking for plans/materials for a tube type coil and a question.

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

Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 2/22/01 2:46:18 PM Eastern Standard Time, tesla-at-pupman-dot-com 
writes:

> Original poster: "Garry Freemyer by way of Terry Fritz 
<twftesla-at-uswest-dot-net>" 
> <garry-at-ndfc-dot-com>
>  
>  I have one set of plans, that uses two 805s in parallel and it says it will
>  put out ~6".

Garry,

I think the 805's have graphite plates.  These tubes can be run over
their specs and can give much longer sparks than 6" in a properly
designed coil.  
>  
>  I am looking to build a tube type coil that would put out a little more 
than
>  that. Between 8" to 12" and would like to get some url's or plans for such 
a
>  coil as well as maybe names of companies to buy the plastic for the
>  secondary and primary.

I show some tube coils at my webpage at:

   http://hometown.aol-dot-com/futuret/page2.html

I like to build my coils to get the max spark lengths from them.

>  
>  I would be interested in buying componants for it. As I will be using my 
tax
>  refund that I'll get back six to 8 weeks from now (about $700), I would 
like
>  to pay fair compensation for any materials I buy. I have about $10 extra
>  taken out of my weekly paycheck towards taxes so that is what most of the
>  refund is. I won't be in a particular hurry to get this up and running. I
>  wish to take my time and build something that looks good as well as works
>  well. If I start with the attitude and expectation that I may be four to 
six
>  months from the time I start building it, I will hopefully be more patient
>  with building it and not be so easily frustrated by delays and setbacks. My
>  idea is to have this finished about September at the earliest.
>  
>  One thing I have been a little puzzled about is that the tube type
>  secondaries seem to follow a 10:1 ratio while the spark gap driven ones 
seem
>  to be more like 5:1 or 4:1 ratio. I am wondering what the reason for this
>  is?
>  
>  Is it because it runs at a higher frequency?

I don't see any benefit from using tall secondaries like that.  I use
ratios of 3:1, or 4:1, or 5:1.

>  
>  Might a tube type coil of 5:1 ratio work better than one of 10:1?

Probably about the same.  But I like the shorter secondaries, because
it makes the sparks look longer by comparison.  My 24" spark VTTC
uses only a 11.5" secondary winding length on a 12" form.  

Tube coils are great fun.  A lot more work to build than a spark gap
coil though.

John Freau
>