Thread: Eric Dollard
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Old 11-18-2012, 02:46 PM
Farmhand Farmhand is offline
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Join Date: Jun 2010
Location: Australia
Posts: 3,387
Oh ok I get it. It's not easy to show a whole setup like that and do everything
alone, good job. I notice with my setups there is an out of phase resonance
at a higher frequency than the tandem 1/4 wave frequency, for me the
tandem frequency is at about 780 kc and the next resonant (out of phase)
condition is at about 1450 kc depending on the tuning it varies of course.
Anyway I notice that if things are tuned a certain way the higher frequency
resonance can be comparable to the lower frequency in maximum voltage but
the primary and secondary are 180 degrees out of phase. I suppose I ought
to check the coil as you did to see whats going on. It is interesting. Did you
try varying the primary capacitance a very small amount or otherwise change
the primary resonant frequency a small amount and tune both ways ? I found
that the length of wire other than the primary itself in the primary circuit is
crucial to tuning as is the ground lead length. I found when I tuned the
primary resonant frequency to a little bit more or less than what is optimal for
the tandem tune when I tune to the higher resonance the effect can be
better. What I see is totally repeatable because it happens with all the three
coil setups I have to a differing degree. And the primary and secondary become
180 degrees out of phase exactly.

I'll do a spreadsheet soon.

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