Re: Questions from a newbie in Australia

["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 4/23/01 3:15:36 PM Eastern Daylight Time, tesla-at-pupman-dot-com 
writes:

> 1.  Instead of a single NST, I have two 15/25 units.  The problem is that 
>  they both have one side of their secondaries shorted (in effect, they can 
>  only put out about 7500V each).  The guy at the sign shop I got them from 
>  said that I could get 15kV out by tying their centre-taps together and 
>  taking the HV from each of the good secondaries (the bad sides are not 
>  connected to anything).  Assuming that I had the primaries wired up in 
>  parallel and in the correct phase, would this arrangement work?

Stacy,

Yes, that will work fine.

>  
>  2.  I'm planning on using a 4" x 20" PVC secondary form wound with #22AWG 
>  magnet wire.  With this size secondary, what would be best in terms of 
>  coupling: a flat primary or a saucer primary?  I've heard that for the 
>  smaller diameter secondaries like mine, a saucer is better, but a lot of 
>  people seem to recommend the flat primary.

I would use a flat primary because it gives plenty of coupling.  Too
much coupling is NG either.

>  4.  At these power levels (~375VA), is there any real benefit in cooling 
the 
> 
>  main gap with a muffin fan or similar? (My main gap will be 11 x 3/4" x 3" 
>  length copper tubes, .028" spacing)

Gaps are finicky, some may need cooling even with low power,
especially with few primary turns in the coil.  You can try it both
ways, and see what's better.  

John Freau