On 30 Apr 2006 20:12:15 -0700, "AC7PN" wrote:

I'm sure the larger conductor has less inductance

Hi Robert,

For a wire, that is not in dispute.

but as Yuri
Blanarovich pointed out earlier the bigger conductor has more
capacitance to free space and that effect must dominate the effect
inductance reduction.

And yet it does not. Components that are significant in size with
relation to wavelength do not exhibit the same qualities. That much
is glaringly obvious.

The problem here is one of a Transform acting upon the expected
outcome. It is generally cautioned here not to treat an antenna as a
transmission line, but this is cautious to the point of ignoring the
solution.

Schelkunoff developed a general formula for the dipole by employing a
biconical structure. This structure operates in the TEM mode and fits
radial expressions for fields naturally described in Maxwell's curl
equations which would be tedious to describe here - so we simple cut
to the chase.

Schelkunoff reveals, mathematically, that this transmission line
analysis presents a finite terminating condition for the current
traveling radially (that is, along the wire out towards the end).
Hence, the biconical form as transmission line never terminates in an
open.

In developing this model towards the thin radiator, the angle of the
cones of the biconical structure fall to a very small value. With
this, the biconical math also simplifies. This simplification does
approach the transmission line condition of an open termination.

The thick radiator falls in between as it is obviously neither thin,
nor conical in shape. As a consequence, neither is it a transmission
line that has an uniform Zc along its length. The formulas usually
used to describe its Zc are an average.

The easy answer comes from this. The two conditions of going from
thick to thin involve two different mathematical basis (providing you
aren't simply going from kind-of-thin to kind-of-thick). This
mathematical basis is transmission line math built on wave mechanics,
not inductors and capacitors. Those are components whose geometries
and size wavelength has condemned to less than useful analogies.

73's
Richard Clark, KB7QHC