Re: Coil form

> From: Julian Green <julian-at-kbss.bt.co.uk> 
> To: tesla-at-pupman-dot-com 
> Subject: Coil form 
> I have spent some time looking for a 10" coil form and have finally found some 
> LDPE pipe.   This sounds like an ideal plastic to use. The only trouble is that 
> it is 12mm thick (its plastic gas pipe). 
> Will this have a significant effect on the Q of the secondary. 
> Does anyone have any experience with this pipe? 
> Julian Green 

I used 6" LDPE in my secondary.  The particular pipe I used was white on the
outside and black on the inner 3/4.  I believe the white outer is so it can be used
with more common PVC fittings and glue.  The tube was pulled from a rather 
large stack and was a touch eliptical and the surface wasn't very even and
had to be sanded down.  I have had a problem with the secondary heating up
a bit during runs, but I'm not sure what is causing it.  Somebody has mentioned
the black plastic pipes could be conductive due to carbon in the polymer, or 
I could have a shorted turn or a high loss coating on it (I used polyurethane),
but I'm not really sure what is causing it.  If the pipe were conductive I'd expect
it to have failed under use by now.

Regardless of all the above, it works great.

Sounds like a good form to me.  Especially if its available to you and the price
is right.  I wouldn't think 12mm would be excessively thick for a 10" pipe.  Let
us know how it turns out.

-Mike McCarty