K7ITM wrote:
On Oct 20, 5:57 pm, Jim Lux wrote:
...
Some might argue, though, that the reason the effective velocity is less
is because the sqrt(1/LC) term is smaller because C is bigger because of
the increased surface area. And that might not be far from the truth
for a restricted subset of antennas.

On the other hand, the propagation velocity of coaxial cable of
constant outer conductor ID is independent of the inner conductor
diameter, even though the capacitance per unit length increases as the
inner conductor diameter is increased. Clearly one must be careful
about attributing the effect to a single cause like increased
capacitance.

Which was the original intent of my comment. Fat radiators are shorter
at resonance than thin ones, and the details of why are not simply
explained by something like "capacitance effects", although such an
explanation may sort of work over a limited range.