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Re: Top Terminal Shape
Subject: Re: Top Terminal Shape
Date: Sun, 18 May 1997 21:21:20 -0500
From: "Robert W. Stephens" <rwstephens-at-headwaters-dot-com>
To: Tesla List <tesla-at-pupman-dot-com>
> Subject: Re: Top Terminal Shape
> Date: Wed, 14 May 1997 00:30:08 -0400 (EDT)
> From: richard hull <rhull-at-richmond.infi-dot-net>
> To: Tesla List <tesla-at-pupman-dot-com>
>
>
> snip again
> >>
> >>Richard,
> >>
> >>With my background in radio astronomy I can support your claim about
> >>the primary field being 'effectively in the next galaxy' by the time
> >>you get to the top of the secondary,.......however I would consider
> >>the field associated with the top region of an excited secondary in this
> >>case to
> >>have some form of an interplay, albeit of reduced power levels to the
> >>primary example, but an interplay with the shorted turn the topload
> >>represents, nevertheless. This *may* explain
> >>a part of the different throwing effects seen from a coil system when
> >>the large toploading, shorted turn toroid is tried at varying heights
> >>above the top secondary turn, over and above what effect the
> >>electrostatic field control also being changed has to do with the
> >>experiment.
> >>
> >>I would expect that the shorted turn represented by the toroid, or
> >>toroid cluster (when more than one are typically used such as my
> >>work) would produce a dampening effect on the slow wave rate of
> >>propagation as it approaches the topload end of the secondary.
> >>Perhaps my practice of NEVER going to expanded turn spacing at the
> >>top several turns of a secondary, but adjusting the top turn-toroid
> >>spacing by
> >>experiment, creates the same effect of damping the wave near the top end
> >>of the secondary. I have been very successful with my approach.
> >>
> >>Grey matter cognitive thoughts encouraged! Those relying solely on
> >>spreadsheets and other computer simulations may tackle this problem
> >>at great personal risk of failure IMO.
> >>
> >>rwstephens
> >>
> >Robert,
> Robert,
>
> Just started maggey #12 as a concept demostrator. This is a radical
> departure as it is a largish table top model which I hope to limit to
> 1KW!
> This will hopefully, result in a larger wall mounted maggey #13.
> (successor
> in power level to maggey 11 series of systems).
>
> It relates to the above discussions and prior posts in that the driver
> coil
> is about a .6:1 ratio system The winding is 6" tall on a 10.6" OD form.
> (#20 wire). The normal characteristics hangin' off the end of my bench
> in
> mid air by a BNC cable are 3.7ohms wire restance. 4mh inductance.
> 705KHZ
> natural res freq.
>
> I built a primary of 5 turns RG-214 (20uh) with a normalized, tuned
> coupling
> of K=.62!
>
> I jammed the top toroid on the driver (12X4) and the inductance of the
> driver droped to 3.92mh OOPS! shorted turn coupled a bit to the
> secondary.
> I need the field control though and it stays where it is. It is also
> coupling to the primary!! dropped the primary to 19.5uh (light
> coupling
> forget it.) It still stays where it is. I would rather waste the power
> than the field control. This is one of those judgement calls where a
> shorted turn on top of the "shallow" system must be tolerated. I can
> afford
> the 20-50 watts of loss more than the coronal bleed to cause arcing in
> the
> driver system. I think I'll resist hacksawing my spun toroid to open
> the turn.
>
> I'll let you folks know how this puppy works out.
>
> Richard Hull, TCBOR
>
>
Richard,
A K of 0.62, wow! Interesting that you are getting magnetic coupling
from the primary to your toroid, this system is indeed tight. I look
forward to hearing of your progress.
Oh, BTW, employing any form of braided conductor as a coil is illegal
don't you know. I did it too on my Coronatron with RG-214 (double
silvered braid). At 2.8 kW CW the tank coil will run all day safely.
At 6.5 kW CW it gets too hot in about 5 minutes and a cooldown is
necessary. I plan to replace it with 1/2 inch copper refrigeration
tubing
as soon as I win the lottery. I plan to push this thing to at least
15 kW CW.
rwstephens