RE: [TCML] Primary tubing

[William Noble <william_b_noble@xxxxxxx>]

this thread did get me thinking - has anyone actually experimented with different sized tubing - it seems to me that for a one or two NST coil there would be no reason to go to somethine even as large as 3/8 tubing - there are two issues, the total resistance of the coil and the value of surface effect.  Increasing resistance can slow rise time, but we are talking a fraction of an ohm here and we don't need nanosecond rise times.  And the frequencies of interest are not all that high, so while surface effect is real, it's not dominant.

So, outside of reasons of aesthetics, has anyone actually compared the effect of different diameters of tubing on a coil, with all ohter things staying the same?  (well, ALL other things can't stay the same becuse a larger diameter tubing with a constant inter winding spacing will result in a larger diameter primary, but you get the idea) - are we just overdesigning here for beauty, or is there a real effect to be demonstrated?  Wny not use plain #10 house wiring - I recall when the consensus changed to using tubing, but I don't recall any actual measurements to prove that the change ITSELF was feneficial.


> From: drieben@xxxxxxxxxxx
> To: tesla@xxxxxxxxxx
> Subject: Re: [TCML] Primary tubing
> Date: Thu, 28 Aug 2008 11:08:04 -0500
> CC:
>
> Hi Rob,
>
> Not to worry. The 3/8" ID/ 1/2" OD tubing will be quite
> adequate for just about any NST driven coil as well as a
> PT or a smaller (5 kVA) pole pig driven coil.
>
> David Rieben
>
>
>
> ----- Original Message -----
> From: "stamsund" 
> To: 
> Sent: Thursday, August 28, 2008 9:44 AM
> Subject: [TCML] Primary tubing
>
>
> Fellow coilers,
>
> Some time ago ordered some 1/2 inch copper tubing on e-bay which I
> incorrectly assumed was 1/2inch plumbing tubing. It was actually
> refrigeration tubing. I just gauged it and found it is actually only 3/8
> inch O.D. not 1/2 Inch as advertised. I'm building an 8 inch coil with (2)
> 12KV 60ma NSTs for a total of 120 MA. Would the 3/8 OD tubing be adequate
> for the primary or should I go larger?
>
> Rob R.
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
>
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla