G4FGQ:

When ground loss is very small (zero if antenna is a pair of two
back-to-back radiators to form a dipole) efficiency is relatively high
anyway, maximumum efficiency perhaps occurring with the coil located in the
lower half of the antenna. The slight improvement relative to base loading
(as part of a tuner) may not then be worth the mechanical inconvience of
fitting a coil in the antenna anyway.


But not in the far field, affecting low angle radiation. Practical results and
measurements show that it is worth the mechanical inconvinience to place the
coils where they belong. Just ask Cecil about results of mobile antenna
shootouts.

An important factor, not considered quantitatively by anybody, is that a
mobile antenna is not just a loaded vertical - the vehicle body, just by
looking at it, obviously forms the major portion of the antenna and is
floating above ground.

At this time it is "bad" enough to look at this one aspect of loaded antennas.
Of course in mobile antennas, the vehicle plays important role. W9UCW excluded
that, used "perfect" radial field ground to eliminate other variables in order
to have a closer look at the current distribution.

Another interesting finding was that there was almost negligible difference in
Q of coils. When they compared "perfect" loading coil (Bugcatcher type) with
"poor" coil of Webster Bandspanner, thay saw fractions of dB difference.

Yuri, K3BU/m