Do you think that a regular half wave dipole cut for 2 meters
hung vertically would be just as good as a J Pole at the same
height even though the J Pole would be cut for a full wave ? A
J-pole is a half wave radiator with a quarter wave matching
stub. In theory, the radiation pattern is exactly the same as
that from a half wave dipole, quarter wave ground plane with
sloping radials, or any other antenna that is about the same
length. In practice things are somewhat different due to the
effect of the feedline. A vertical half wave dipole works well
if the feedline can be kept from affecting the pattern, for
example, by side-mounting the antenna on a mast using a stand-
off with the feedline running away at right angles to the
antenna. If you just stick the dipole on top of the mast with
the feedline running down beside the lower element, that doesn't
work as well. (One common commercial solution is to bring the
feedline down inside the bottom half of the dipole.) Similarly,
a J-pole is prone to common mode cur