About J-POLE ANTENNAS by Mike Walkington, VK1KCK The J-Pole antenna is an omnidirectional antenna that can be used for base, mobile and field day stations. It does not need a ground plane, radials or a complicated matching system. The J-Pole can be cheaply, simply and quickly constructed using a variety of techniques, some of which…
Category: Antenna Theory
Why Are Antennas Built to Look Like They Do?
We come to recognize the proportionate shape and appearance of antennas. If we see a half wavelength dipole we recognize it for the antenna it is. When we see a Ground Plane antenna we know what it is. Its just the same as when we see a Ford automobile next to a Volkswagen we know…
Low Noise Antenna Connection
From: jpd@space.mit.edu (John Doty)Newsgroups: rec.radio.shortwaveSubject: Low Noise Antenna ConnectionDate: 26 Nov 1993 16:55:24 GMT It doesn’t take very much wire to pick up an adequate signal for anything but the crudest shortwave receiver. The difference between a mediocre antenna system and a great antenna system isn’t the antenna itself: it’s the way you feed signals…
Antenna mounting height – the higher the better?
For someone surrounded by houses, power lines and trees, a 30m/98ft high tower is desirable. A high tower is also desirable for someone situated on perfectly reflecting ground, such as saltwater. However, in most “real world” cases, the 30m/90ft height is less advantageous than you might think. Why is this the case? The angle of…