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Re: coupling factor?
Subject: Re: coupling factor?
Date: Fri, 9 May 1997 22:16:13 -0400 (EDT)
From: Esondrmn-at-aol-dot-com
To: tesla-at-pupman-dot-com
In a message dated 97-05-08 00:37:02 EDT, you write:
<<
Let me pose this in two parts. I will begin with a thank you to
Richard
Hull for the info he sent regarding
this. By the way Richard, my secondary is built up of #26 AWG heavy
coated wire.
1. Why do most TC builders raise their secondaries out of the primary
when they tune (or even lower them)?
Why not move the primary since it is smaller and has no "top heaviness"
like the secondary. Please explain in
great detail the parameters involved and ideas to work on.
2. Could someone please explain (again) where to start when tuning the
completed TC and how to make the final
adjustments.
Thanks to all who answer, please use the same Subject heading to cut
through some of the chatter on the list.
Chuck
>>
Chuck,
I believe most of us change the height of the secondary because it can
be
done easily by adding or removing spacers under the secondary. Moving
the
primary will achieve the same result but is usually more difficult
(depending
on your construction) because it is larger and has heavy wires
connecting it
to the spark gap and capacitor. Often these "wires" are rather
inflexible
copper tubing.
When I tune my coils, I first have done all the calculations so I know
the
primary will tune with the loaded secondary - if I have done it
correctly,
somewhere near the outside few turns of the primary. I set up a point
on the
toroid and a position a ground wire maybe a foot away in a direct line.
The
distance of course depends on the size and power of the coil. Now I run
the
coil at low power and tune for best spark. As you increase the power
level,
the secondary tune point will need to be moved out (increased
inductance) as
higher power levels will cause a larger ion cloud around the toroid and
decrease the frequency. One half turn increase on the tap is not
unusual.
Ed Sonderman