RE: Conical Primaries (was Conical secondaries)

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

Original poster: "John H. Couture by way of Terry Fritz <twftesla-at-uswest-dot-net>" <couturejh-at-worldnet.att-dot-net>


Bart -

You may be correct about the flux linkages. I was thinking about the
coupling which is about .195 for the spiral and .326 for the helical coil
for the JHCTES default coil. More coupling more flux linkages? Your tests
will provide the correct answer. There is nothing that beats a test when a
question arises.

John Couture

-------------------------------


-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Thursday, May 03, 2001 6:57 AM
To: tesla-at-pupman-dot-com
Subject: Re: Conical secondaries


Original poster: "Barton B. Anderson by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <tesla123-at-pacbell-dot-net>

Hi John,

Yes, I'll report my measurements on cone primary's but I believe flux
linkage will actually be less than helix
or spirals when the inner diameter is unchanged for reason's regarding the
inducing relationships between turn
to turn and with those, the inducing affect the secondary has on the
primary at these angles. Tests will either
confirm this or prove otherwise. I can't run sparks at the moment for two
reasons. Spark gap is in the middle
of a change (dc motor controlled phasing - I personally like this as
compared to a variac phasing method) and I
knocked over BC2 (12.75" secondary) this weekend with toroid Fr
measurements. I had pulley above adjusting
toroid level and when I wasn't looking, it fell over landing on my dc sync
adjustment motor (low gear speed
type) and put a 2" dent in the secondary about 3/4 from the top of the
secondary. Measurement's are fine at low
voltage, but I'll have to repair for high voltage sparking. Probably flip
over after repair.

I'll report my findings upon measurement. BTW, toroid measurements are
showing approximately 16% lower Fr when
toroid is mounted vs. no toroid. This equates to a larger than 16% if
applied to toroid capacitance. However,
as far as the height above the secondary, the Fr changed only slightly. I
think it's wise to change the Fr
appropriately vs. a toroid or sphere capacitance adjustment, but I need to
check the sphere next as well as
another toroid (smaller in cord but larger in diameter across), as well as
another toroid even smaller I have
on hand.

Also, I did running Fr measurements with a loop antenna a year ago and the
Fr as compared to low voltage
measurement using a Frequency meter and Terry's tuner circuit differed by
only 1kHz. This technique of
measurement is proving very accurate. I wasn't worried about actual Fr, but
more concerned with Fr change,
however, it appears to agree regardless (added benefit). As with TSSP, the
inductance may be changing, but in a
program, what is important is that either Ls or Ctotal is adjusted to
appropriately predict Fr so that the
primary is accurately adjusted.

Take care,
Bart A.

Tesla list wrote:

> Original poster: "John H. Couture by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <couturejh-at-worldnet.att-dot-net>
>
> Bart -
>
> I haven't seen any test data on flat vs inverted cone primaries and will
be
> anxious to hear about what you find. It is my understanding that the
> advantage, if any, of the inverted cone is that it provides more coupling,
> more flux linkages, and more output compared to the flat primary. In other
> words the inverted cone gives the advantages of both the flat primary and
> the helical coil primary.
>
> Could you test not only the inductances but also the couplings using the
> same secondary coil? Testing the outputs would also help but could be very
> difficult using a test method with metered inputs and controlled sparks.
>
> John Couture
>
> ------------------------------
>
> -----Original Message-----
> From: Tesla list [mailto:tesla-at-pupman-dot-com]
> Sent: Wednesday, May 02, 2001 7:02 AM
> To: tesla-at-pupman-dot-com
> Subject: Re: Conical secondaries
>
> Original poster: "Barton B. Anderson by way of Terry Fritz
> <twftesla-at-uswest-dot-net>" <tesla123-at-pacbell-dot-net>
>
> Hi,
>
> Interesting you brought this up. I just bought 100 ft of primary tubing at
> Home
> Base (btw, going out of business and 50 to 70% off) to wind conical
> primary's and
> test against calculated inductances via Fr measurements. Conical primary's
> are
> cone's (I know, duh). The only problem with a conical primary is that the
> outer
> windings are typically higher up on the secondary and therefore have
greater
> potential to take a strike from the secondary streamers. What if it is
wound
> downward? The secondary coupling would then need to be checked via current
> measurement to see how far down the secondary should actually be to
achieve
> similar coupling on an upright cone. This is part of my current
experiments
> coming
> soon.
>
> Bart A.