Don't 5/8 wave antennas require a loading coil?
Loading coils are one way of matching said antenna, but not the only way. Any form of impedance matching that can convert the feed point impedance of said antenna to a 50 ohm resonant load will work to match said antenna. In the case of this antenna, a loading coil is just one way to accomplish this.
The Super Penetrator uses a hairpin type match. Several antenna designs use a tapped coil, which should not be mistaken as a loading coil as it functions very differently. Some antennas that use said methods, such as the Maco V5/8 and V5000 have a capacitor as well, in the case of the Maco antennas it is actually hidden in the design. Others use a design that doesn't require the capacitor.
The Imax 2000 actually uses a capacitor up on the antenna itself as a load, which allows them to use what is essentially a half wavelength matching transformer to match said antennas.
I've seen a guy use a gamma match to match a homemade 5/8 wavelength antenna before, as well as stub matching.
In short, there are any number of ways to match a 5/8 wavelength antenna that doesn't require a loading coil. However some people will mistake some of said components to be the same as a loading coil simply because somehow they look the same.
The DB