Is J-Pole a good antenna?
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Is J-Pole a good antenna?
The myth is that j-poles have lots of gain and are better than anything else. A j-pole is just a 1/2 wave end fed antenna fed with a 1/4 wave transmission line matching section. If constructed and tuned properly, they only have as much gain (0 dBd) as a dipole.
Do J-Pole antennas have gain?
Primarily a dipole, the J-pole antenna exhibits a mostly omnidirectional pattern in the horizontal (H) plane with an average free-space gain near 2.2 dBi (0.1 dBd).
Is a J-pole antenna balanced or unbalanced?
The J-pole is a good example of a poorly implemented feed system, because it mixes balanced and unbalanced systems. In the J-pole, an unbalanced end-fed half wave radiator is fed by a balanced 1/4 wave stub. The balanced stub is fed by unbalanced coaxial cable.
What is a Slim Jim antenna?
The Slim Jim Antenna. The Slim Jim is a vertically polarized omnidirectional end-fed antenna having considerable “gain” and this is concentrated almost parallel to ground toward the horizon rather than skyward making it more efficient than a ground plane type antenna by about 50 percent better.
How good is a Slim Jim antenna?
The Slim Jim is probably one of the cheapest and easiest antennas to make, and it’s a very handy one too. You can typically make one of these for under £10, they roll up easily for storage and travel, and are great for use at home, or when travelling, for accessing local repeaters.
Is a Slim Jim antenna directional?
SLIM JIM ANTENNA PROJECT. The Slim Jim is a vertically polarized omnidirectional end-fed antenna having considerable “gain” and this is concentrated almost parallel to ground toward the horizon rather than skyward making it more efficient than a ground plane type antenna by about 50 percent better.
How do you ground a Jpole?
hammer the top of the rod with a 5 pound hammer or small sledge hammer. As the rod is driven down, you may need to descend the ladder for the best angle to drive it. Once the rod is within a few inches of the ground, you can stop.
Are Slim Jim antennas directional?