AOR AR8000 Operating Manual page 109

As a compromise it may be worth making up a dipole aerial for a band of
particular interest and have a VHF-UHF discone plus second random wire for
general listening.
It is quite easy to make a dipole for shortwave, for that matter one can be
easily made up for VHF or UHF too. If being made for VHF-UHF the centre
connection of the coaxial cable feeds the upper element set vertically.
Shortwave dipoles on the other hand are usually mounted horizontally
It is worth noting that dipoles are also quite effective on two and three times
their design frequency so you can cover a few bands at once. Reception using
a half wave dipole is best at 90 degrees to the direction the aerial is laying,
however if used at two or three times it's fundamental design frequency,
reception is best closer to the direction the aerial is lying.
A dipole has two legs running in opposite directions and can be mounted
vertically or horizontally (most VHF activity is vertical). One leg is connected to
the centre conductor the coaxial feeder cable while the other leg is connected
to the outer screen of the coaxial feeder cable. If mounted vertically the centre
of the coaxial feeder should be connected to the leg facing upward.
A simple formulae can be used to calculate the required length of each leg for
a half wave dipole:
75
———————— = Length of each leg in metres
Frequency in MHz
i.e. For 14.2 MHz
75
——————— = 5.28 metres (i.e. the total length of
14.2 the aerial is twice 5.28m.)