Re: coupling

To: tesla-at-poodle.pupman-dot-com
Subject: Re: coupling
From: Tesla List <tesla-at-stic-dot-net>
Date: Mon, 05 May 1997 01:32:16 -0500
Approved: tesla-at-stic-dot-net
Subject:  Re: coupling
  Date:   Sun, 4 May 1997 19:49:19 -0400
  From:  "Thomas McGahee" <tom_mcgahee-at-sigmais-dot-com>
    To:  "Tesla List" <tesla-at-pupman-dot-com>



----------
> From: Tesla List <tesla-at-pupman-dot-com>
> To: tesla-at-poodle.pupman-dot-com
> Subject: coupling
> Date: Saturday, May 03, 1997 2:19 AM
> 
> Subject:   coupling
>   Date:    Thu, 01 May 1997 16:39:42 -0400
>   From:    chuck seguin <seguinc-at-algonquinc.on.ca>
>     To:    Tesla List <tesla-at-stic-dot-net>
> 
> 
> Good afternoon,
> 
> I understand this next question was already answered by Richard
Hull.  I
> would like, if possible, a more 
> detailed explanation.
> 
> Why do TC builders, in general, lift the secondary out from the
> primary?  Actually, why move the secondary at 
> all to change the coupling?  Would it make sense to move the
primary
> instead?  It seems easier to perform.
> 
> Next, how does one begin to tune a TC, and what do we look for when
> doing it?  Please be as detailed as 
> possible so that I may take notes and compare with my method.
> 
> Thanks to all that will help.
> 
> Chuck

Chuck,
As far as the COUPLING is concerned, it makes absolutely NO
difference whether you move the primary or the secondary. However...
There are good reasons not to move the primary. 

The primary is attached by wires to the rest of the tank/supply
circuit. Moving the primary is therefore usually a messier
proposition than moving the secondary. Which isn't to say that moving
the secondary is not sometimes messy, too.

If you move the primary winding you are not only affecting the
coupling, you are *also* changing in subtle ways the geometry of the
entire tank circuit. In general moving the primary is more dangerous,
harder to accomplish, and has more "side-effects" than moving the
secondary.

The one possible advantage that moving the primary *might* have over
moving the secondary is that it allows you to have the secondary
mounted more firmly, (perhaps). But there are ways of making the
secondary the moveable piece and still having it mounted securely. 

Perhaps some of those who have come up with simple or elegant ways of
doing that will share them with us. 

Note that with large top loads it becomes more and more important
that the secondary be firmly mounted. Unless you actually enjoy the
adventure of having your secondary topple over in the middle of a
run, of course. :) Same goes for mounting the toroid to the top of
the secondary.

Fr. Tom McGahee