Re: First Secondary (repost)

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

Original poster: "Hans Scholze by way of Terry Fritz <twftesla-at-uswest-dot-net>" <hanscs-at-eagle.ptialaska-dot-net>

I am reposting this because i think for a few days all my
outgoing mail was ending up in that big black somewhere deep
beneath my ISP's office.

For my latest coil, I made a a support from 1/4 inch HDPE. 
I cut two pieces 10" long and 4.25" inches wide (my
secondary has a 4" ID), then carefully shaved them down
until they fit snugly in the form.  I was lucky enough to be
able to use a jointer, but you should be able to do it with
a sander or hand planer.  Then I cut 1/4" slots 5" up from
the bottom of one and five inches down from the top of the
other so that they slide together to make an X when viewed
from the top.  Next I screwed the two pieces to the base. 
Compared to previous methods I have tried (AIEEEE, its
tipping our way!!), it works great.  The secondary can be
slid up and down to change the coupling, but grips the
support tightly enough to stay firmly in place without
anything else holding it.  I tried a cylinder as you
mention, but it didn't work as good because with the X the
secoudary can deform slightly to fit tightly, but with a
cylinder, you tolerances have to be very tight.

Hans


Tesla list wrote:
> 
> Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<stanmoore-at-mindspring-dot-com>
 
<Snip>
 
> How are folks attaching the secondary to the support plate?  I was
thinking of
> using a smaller cylinder to slide the coil over.  That would allow for some
> vertical adjustment when tuning.  Thoughts?
> Stan