As straight wires are usually better radiators than the same wire in
coils, I speculate that the current drop measured by Yuri is mostly due
to the high impedance (High voltage, low current) on the output of the
loading coil.
What, Coililng the wire has nothing to do with how well it does or does not
radiate, only with how the radiation is summed into the total field. The
current distribution in a loading coil should be very similar to the current
distribution in the secton of antenna it is replacing.