Re: Cage type secondary former

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

Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>

Hi Steve,

My local plastics guy just says to get thin plastic (I think he said Lexan, 
but I am not sure) and bend a flat sheet over into a tube and glue it 
up.  I didn't get all the details since it was busy wildly diving into the 
free scraps bin, but he seemed to think it was a real easy thing to do.  I 
am not sure how the seem is made but this guy can glue edges that are 
invisible with solvents that "melt" the plastic edges together just like 
they were made that way.

Cheers,

         Terry

At 08:47 PM 5/12/2003 +0100, you wrote:
>Dear list,
>
>I've been wracking my brains to try and find a suitable former for my OLTC 
>secondary. I was looking for a thin walled plastic pipe 10" dia x 30" 
>long. Then I thought, why do I need to use a large pipe at all? I could 
>make a round cage-like structure from a number of 30" long PVC drain pipes 
>and a top/bottom/stiffening plates made out of PVC or wood.
>
>I'm not sure if this would work, though. On the plus side it might have 
>lower losses since the winding is mostly in air. On the minus side though, 
>the field control might be poor because it's not perfectly circular and 
>there's no way to fit baffles. Mind you, I noticed Bill Wysock's Super 
>Model 13M used a secondary/extra coil wound on a wooden cage and it seemed 
>to perform reasonably well &) However, just because it works for a 30 foot 
>tall 700 turn extra coil doesn't mean it'll work on mine... Has anyone 
>ever tried an open frame secondary like this on a more realistically sized 
>coil? How did it go? Was it a pig to wind?
>
>TIA
>
>Steve C.
>