1iwilly, you would do well to go back and read through this thread, as the info that shows exactly why the antenna you showed is a bad design, and why all these guys who purport these things are either uneducated on the subject, or just plain liars.
the 1/2 S unit thing comes from the idea that running a reflector behind your main radiator will reduce the gain in the rear direction and increase the gain in the forward direction.
if this is done exactly right, it is possible to achieve about a 3db gain theoretically.
if the salesman says its because his antennas are superior to others, he is lying.
in fact, i would think that adding those cap hat things on top could really mess with the relationship between the two vertical radiators.
the absolute best way to do this would be with two 102" whips. anything shorter will be a compromise.
its amazing to me how fast these guys who sell to the competition crowd start copying eachother.
one guy starts putting an electrolytic cap in his amps so they all start doing it.
one guy puts a cap hat over a coil because he read the ARRL handbook and sort of understood it, and they all start doing it.
lets all be clear here. a cap hat over a coil is not necessarily a bad design, BUT attention must be paid to the exactly correct placement of the cap hat and the inductance of the coil.
if done correctly, the cap hat can help reduce the resistance of the coil because less inductance is needed which will help reduce the losses.
that is the reason to use a cap hat over a coil.
it will never be as good or better than a 1/4 wave radiator.
LC
