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Re: Bi Polar coil
Hello Ed, all,
> You want to build the secondary to whatever dimensions you want, then
> calculate its resonant frequency with whatever terminals you will use on the
> ends. Then calculate the primary coil and capacitor using 1/2 of the
> secondary frequency. It is basically two 1/4 helical resonators driven at
> the center with no ground refrence to the secondary.
This raises an interesting one that I've noticed on a one-off basis.
One day I idly laid a resonator on its side and did the calcs on it
using the formula I know hold good for vertical 1/4 wave secondaries.
Imagine my surprise when I found that the thing resonated 1/2 wave
at a higher (from memory) frequency than the formulae predicted
(modified Cself possibly due to lying on its side). I had an untuned
primary coupling the signal generator in to the centre of the
structure. Perhaps something else that needs a bit more theoretical
work. Anyone else tried this?
Malcolm