Re: 3/4 wavelength secondaries

Tesla List wrote:
> >From 100624.504-at-CompuServe.COMSat Aug  3 06:59:51 1996
> Date: 02 Aug 96 17:43:49 EDT
> From: Alan Sharp <100624.504-at-CompuServe.COM>
> To: Tesla List <tesla-at-poodle.pupman-dot-com>
> Subject: Re: 3/4 wavelength secondaries
> Skip
> > An obvious
> >answer is to use a flat spiral secondary, as I believe Tesla envisioned,
> >to raise the Lp to the highest value, but I can't figure out how to build
> >it.
> >Oh well, tomorrow is another day
> The only way that I could see to build this is to make a bobbin that is just
> over
> the wire diameter high - 2 large flat steel plates lined with plastic sheet,
> with a
> suitable spacer in the middle, fix wire
> in centre and wind. Remove top, (it might go ping) slide off the top varnish
> as you go, remove bottom.
> Just an idea
> Alan

I have done just that but I used two plastic sheets and wound the wire 
between them. Construction worked fine but the inductance was essentially 
the same as a solenoid wound coil of the same length.