Re: 3/4 wavelength secondaries
Tesla List wrote:
> >From MALCOLM-at-directorate.wnp.ac.nzWed Jul 24 21:38:58 1996
> Date: Wed, 24 Jul 1996 19:55:42 +1200
> From: Malcolm Watts <MALCOLM-at-directorate.wnp.ac.nz>
> To: tesla-at-pupman-dot-com
> Subject: re: 3/4 wavelength secondaries
> Hi Skip,
> I have guess to make based on some calcs I did over the
> weekend. I think the best you can do without top C is to approach
> a 1/2 wave coil. My findings were exactly yours regarding the 3/4
> wavelength job. It is clear one can reduce the fractional wavelength
> to very low values with arbitrarily large top C (e.g. 1/8 or less).
> <large snip>
> > In any event I do not believe a 1/4 or 3/4 wave coil can be wound in any
> > "reasonable" configuration. In fact the resonant frequency of 1/4 wave
> > coils is always about 40% higher than the 1/4 wave wire length and a
> > toroid must be used to bring in the frequency even taking into account
> > the increase in cself due to ionization. The resonant frequency of a 3/4
> > wave coil is always lower than the 3/4 wave wire length so the 3/4 wave
> > coil cannot be tuned at all.
> <more snip>
I agree. I have built 1/2 wave coils.