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Pondering a more effective HT Antenna?
James186282 wrote:
I've been trying to understand the basics of HT radio antennas. The first part that puzzles me is the "ground" side of an antenna. Or if I can use a Dipole as an example one side of the dipole. Or if we use a groundplane the radials. With an HT are we just "doing without"? Or is this just my dumbness in action? Antennas are a lot easier to understand if you forget about "ground" unless you're talking about a direct connection to the earth. Calling one side of an antenna "ground" doesn't impart special qualities; current flowing on any conductor creates a field, and it doesn't matter if it's on a "ground" side of an antenna or any other part of it. Some structures like a "ground plane" elevated radial system are designed to carry current yet radiate very little, so they're reasonably called "counterpoises". My second question is in asking how effective is the typical rubber duck antenna versus say a truly resonant antenna or even a 5/8th wave which tries (if I understand it) to squish the pattern down from a sphere to a doughnut so its hears and talks better out then "up and down" A rubber ducky has, for practical purposes, exactly the same pattern as a quarter wavelength antenna. Longer antennas have different patterns. But remember, your HT and body are just as much a part of the radiating antenna system as the "antenna". If you put, say, a half wave whip onto your HT, your body and HT are more effectively removed from the system (although they'll still radiate some due to coupled current). That will likely make more of a difference to the pattern than the difference caused by whip length. In my mind I would simply like an antenna that was effective but flexable. Length is not "critical" as I plan to hang it up high on an LB harness. The idea is a rough and tumble antenna that can work in the woods on a Search and Rescue mission but will give me the very best range out (not so much up/dn) Has anyone done any serious work with HT antennas? Is there anyone clued into how to match these properly? And has anyone looking into using spring steel (Such as Measuring tape) for the antenna as the Military uses in many of their radios? I'd think military implementations deserve a good look, since they have similar requirements to yours. Any solution will be a trade-off, so you have to decide what you're willing to trade for what you'll get. I recommend you get the _ARRL Antenna Compendium, Vol. 4_ and read "An Investigation of 2-Meter HT Antenna Performance" by Ken Pierpoint KF0OW and Ed Brummer W4RTZ. It's the only experimental work I know of on the topic which has been published in the civilian press. The results aren't totally unambiguous, but it's a good study. Roy Lewallen, W7EL |
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