Re: component sizing

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

Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <Tesla729-at-cs-dot-com>

In a message dated 2/19/01 10:20:44 PM Pacific Standard Time, 
tesla-at-pupman-dot-com writes:
tom, you wrote:

<< 1.  From Ed Sonderman's Excel spread sheet I was planning on trying to get 
 <a tank cap with a value of around .028 uF.  Does this sound correct, and if 
< so, what is the best way of obtaining the tank caps?  I have a limited 
< budget, but I am also trying to make a very nice looking coil.
 
.028 uF would be a good LTR cap for a single 15/60 NST, but if you're wanting
to get 2 more NSTs, then you will need a somewhat larger primary capacitance
to run larger than resonant (LTR). For 15/180, you should probably go for 
about
.06 uF. Get in on Terry's MMC bulk buy and build up to the needed capcitance
or check out ebay for Maxwell caps. .06 uF is going to get into your pocket
whether you go with an MMC or a commercial pulse dischrge cap (-at- least 
$200).

 <<2.  I wanted to make a RSG.  I have access to some DC motors and 
 <<controllers, but I have seen a few places mention that an async-RSG is bad 
 <<news for NST's.  should I stay away from the DC motors?

Yea, really you should stay away from anything but a salient synchronous
RSG for an NST system. I have personally smoked NSTs within < 2 seconds
trying to run them on an asynch RSG.
 
<< 3.  I have some 1 1/2" acrylic that I was planning to use for the rotor of 
<< my RSG.  I am planning on drilling and tapping 1/4-20 holes in it and 
using 
<< threaded rod with acorn nuts on the ends for my electrodes.  is this a 
good 
<< plan or bad?
 
Nope, you'd better go with at least polycarbonate (lexan) for your RSG 
disc. G-10 is the best, but it will cost you. I've used 3/8" thick lexan disc
with my pole pig system with no problems. Acrylic will likely shatter under
the centrifugal forces developed by the rotay electrodes and the electrodes
can become literal "bullets"!

<< 4.  RF chokes.  what are some good designs, and How do I size them?
 
I think you should probably just go with Terry's protection circuit at 
<http://users.better-dot-org.tfritz/NSTFilt.jpg>. I've found that the homemade
RF chokes are usually nothing more than window dressing.

<< 5.  what is the best method of constructing a toroid that would be large 
<< enough for my coil?
 
Go to your local home improvement supply warehouse (Home Depot if 
you're in the US) and purchase some of the aluminum flex-duct dryer 
hose. It usually comes in 8 ft. lengths and will be from 4" to 8" in dia-
meter. Just fabricate one (or 2 pieces if you want to make a bigger one)
into the donut toroid shape and hold it into shape with aluminum tape.
Any toroid with an outer large diameter of more than 26" to 28" will re-
quire 2 pieces of the 8 ft. aluminum dryer duct.

 <Thank for your help
 
< Tom Back >>
  
David Rieben