> The reason the difference is small is that the current diminishes so
rapidly
> in the first few turns of lumped inductance, whether Hi-Q or LO-Q, and
> therefore only the loss in those turns is being compared. The same is
true
> for inductively top loaded base station verticals. Loss in the coil is
> insignificant. Most calculations to the contrary made in texts, articles
and
> some modeling programs are based on the current being equal throughout the
> coil. This is not true. Of course, most mentions of this loss are not
> quantified at all.
I agree with most of what you say Barry, but I disagree with the above.
Current in ANY *non-radiating* two-terminal device or component is exactly
the same at each end, this includes capacitors and inductors.
With the single qualification loading coil length is small compared to the
physical length of the antenna, current is essentially uniform in the coil.
The lack of difference in performance comes because the **system** losses
are so high from ground losses, the resistance and Q of a coil change is
diluted by fixed losses. It also goes directly to the fact reducing
end-to-end capacitance by using a long form coil can reduce loss in
low-capacitance systems.
73 Tom
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