Re: Secondary construction details

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Esondrmn-at-aol-dot-com>

In a message dated 9/27/01 5:16:23 PM Pacific Daylight Time, tesla-at-pupman-dot-com
writes: 


>
> Howdy All, 
>
> I am preparing to wind my 6.5" secondary, and had a couple of questions, as 
> usual. 
>
> What is the usual arrangement for the bottom contact of the secondary? I was 
> thinking of using a nylon bolt from the inside of the secondary. Is this ok? 
> Do most people drill two small holes and pass the wire through one to the 
> inside of the coil, then back out through the other, or is having the wire 
> inside the secondary at all a no-no? As for the top, I am planning on making 
> a disk of the correct diameter and gluing it in, with a brass bolt in the 
> middle. Any better ideas? 
>
> The form I have (pvc sewer pipe) is a little beat up, it's never been used 
> but has some scratches and so on. I was planning on an acetone cleaning and 
> then a little sanding with 120 grit. Sound reasonable? 
>
> Thanks, 
>
> Jonathan Peakall 



Jonathan, 

I would not run the wire inside the secondary form.  I cut a piece of 1/4"
plastic into a circle about 2.5 to 3.0" larger in diameter than the outside
diameter of the secondary.  Then I cut a piece, maybe 3/4" to 1.0" thick (you
can glue a couple of pieces together) that just fits into the secondary.  Now
center this piece on the previously cut disc and glue them together.  Now glue
this to the bottom of the seconday.  This makes a nice strong base to mount the
secondary with.  I drill three 1/4" holes in the mounting disk and use two
nylon bolts and one brass bolt to mount the secondary to your platform,
plywood, whatever.  The wire on the bottom of the secondary is terminated in a
1/4" eyelet.  The brass bolt goes through the eyelet and connects to the main
RF ground on the bottom side of the plywood.  Works good for me. 

Ed Sonderman