"big wheel" is a
horizontally polarized omnidirectional antenna .
Normally, high gain directional antennas are to be used for VHF or UHF
communication, in order to multiply the radiated energy into the desired
direction or get rid of interferences from other than the desired
direction. However, the directional characteristics of a beam antenna is
not always an advantage or wanted. For general coverage purposes, an omni
pattern is desirable allowing the operator to scan in all directions for
signals of interest. Normally the beam stays directed into the general
direction of most radio activities and some possible contacts may not be
heard. That's when the Big Wheel comes to play: It's an ideal antenna to
be used on top of the high gain yagi as well as a great
omnidirectional antenna for contesting. These antennas are made
of anti-corrosion aluminum material and all nuts and bolts are made of
stainless steel. The gain is approx. 3dBd and the antennas utilize an
N-connector. It's possible to stack two Big Wheels horizontally and thus
increase the gain to approx. 5 dBD onmidirectionally! For correct coupling
and tuning of both antennas, it is recommended to use a phasing
line
