On Sat, 20 Mar 2004 22:15:52 GMT, "Henry Kolesnik"
wrote:

If I'm treading old ground please excuse the post. Today at the local
hamfest I ran across a 20 meter Isotron that the seller touting. After
looking at its simplicity and hearing how great it was I couldn't resist
because it was only $10.00. So now that I have it, I'm curious as to the
theory behind it and how an 89 turn coil of No. 12 wire on a 3/4" piece of
PVC along with a 12" aluminum rod and a couple of aluminum plates can load
and dissipate 1000 watts. I've seen their ads for years and always thought
they were snake oil but at $10.00 I bit. Anyone really know the theory
behind these things?
tnx
Hank WD5JFR


Hi Hank,

This intersects with so many recent topics, it is hard to know where
to begin.

First, undoubtedly through the combination of capacitance (the plates)
the inductance (the windings) and radiation resistance, it resonates
and sheds heat like your grandmother's clothes iron. That it is so
small, it automatically removes it from concerns of being too big to
qualify as lumped components (I will bet the current into the coil
nearly equals the current into its other end).

Some claims bandied here would have us believe that its "high Q"
renders an efficiency (per unit length) unparalleled since the days of
Watt's steam engine. It must certainly be competitive with italian eh
models and show more gain than a Georgia AM station converted to cfa
(but only for the first 300 yards).

If none of this satisfies your quest for understanding; then you can,
of course, visit the vendor's site, observe their "how it works"
description and then find the exact same wording in an unbiased review
from 1996. ;-)

73's
Richard Clark, KB7QHC