herbert.don wrote:
"coke = pepsi woohoo!"

A loading coil is important to tune out the capacitive reactance of a
too-short whip so that maximum current can be put into the antenna to
get the most RF radiation out.

A loading coil usually has some loss that takes the form of heat
converted from some of the energy pumped into it.

One of the debates here may have been triggered by reference to John
Devoldere, ON4UN`s treatment of "short verticals" in "Low-Band DXing".
He discussed several ways to resonate the too-short vertical antenna.
His Fig. 9-22 on page 9-15 of his 1994 edition became notorious.

ON4UN occasionly characterizes coils as having "degrees" in the space
occupied in the antenna. No one argues that a 1/4-wave vertical does not
have 90 degrees, or that at a given frequency, you could not properly
say a certain linear measure was not equal to a degree. So, if you are
trying to resonate the antenna as a 1/4-wavelength, why not assign the
missing length of antenna, in degrees, to the coil or coils which
replace the missing length of antenna?

The number of turns required of the coil or coils depends on where it or
they are placed in the antenna. A certain number of turns are not
predetermined to represent so many degrees independent of placement.

More than just resonating the antenna, placement of the coil or coils
affects current distribution which affects radiation and loss. Several
problems need simultaneous solution to get the best performance.

I have mostly thought of the velocity of light as being a universal
speed limit. I read long ago that energy is transferred by passing an
impetus along a group of extremely short gap distances through a file of
charges. The individual charges are migrating slowly, if at all, and
going nowhere fast. Speeds greater than the speed of light seemed
inconceivable to me. Researching the loading coil brought me to Kraus
and his helical antenna. On page 253 of the 3rd edition of "Antennas" is
Figure 8-32. For certain coils it shows velocities exceeding the speed
of light. I guess I`m not too old to learn after all.

Best regards, Richard Harrison, KB5WZI