Built Your Own Omnidirectional Airband Antenna
Built your own omnidirectional airband antenna.
VHF Airband frequency spread from 118 to 136 MHz.
VHF Airband receiver capability include on many modern Scanner, but standard antenna in Scanner usually portable but poor of gain signal.
to improving the performance of Scanner for Airband reception, you can use external antenna.
you can easy make match antenna such as Ground plane to operate in this band. in this article, i suggest to built self and easy some Ground plane antenna.
The Ground Plane vertical is omni directional antenna, its suitable for Airband receiver, Airband scanner, or Airband radio for monitoring several airport tower or aircraft planes en-route.
this is some explaination about “omnidirectional antenna” from Wikipedia: An omnidirectional antenna is an antenna system which radiates power uniformly in one plane with a directive pattern shape in a perpendicular plane.
This pattern is often described as “donut shaped”. Omnidirectional antenna can be used to link multiple directional antenna in outdoor point-to-multipoint communication systems including cellular phone connections and TV broadcasts.
so whats the meaning of Ground plane antenna?
the vertical length (height) of a quarter wave ground plane antenna, and the length of each of the four radials (often called radiators) for the frequency chosen.
The normal quarter wave ground plane antenna consists of a vertical radiator which is insulated and centered between 4 horizontal surrounding radials which extend out from the base of the antenna.
Each radial is evenly spaced (90 degrees apart from each other) around the vertical element.
The Ground Plane vertical omni directional antenna is very easy to build with just some #12 solid copper electrical wire.
Bend the radials to a 45 degree angle away from the coax and masting. Then trim to length measuring from the outer edge of the dielectric to the tip of the wire.
To optimize the antenna for a frequency RANGE you can choose center the range on frequency spread as needed.
All antenna lengths depend on various factors.
Some of these factors are: the height above ground, the diameter of the wire, nearby structures, the effects of other antennas in the area and even the conductivity of the soil.
(Because of the artificial ground provided by the radials, the height above ground should have little effect on this type of antenna.)
It uses the standard formula, 234/f MHz to calculate the element lengths.
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