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On 22 Sep, 20:36, Walter Maxwell wrote:
On Sat, 22 Sep 2007 19:19:18 -0700, wrote: On Sep 22, 5:40 pm, art wrote: O.K. I may have muddied things. I hold to the fact that a one wavelength dipole will always radiate at a higher efficiency than a 1/2 wave dipole. If it does, I doubt it's enough to measure on the air.. The example I gave as for an instance was a quad versus a 1/2 wave dipole. This is readily seen by any operator empirically. I've never seen it here. For that reason, I hardly use loops. Neither vertically oriented, or horizontal as for NVIS use. I don't see them as worth the extra trouble. Being I tested them on 75m using NVIS paths, a noticable difference in efficiency should have been readily apparent. It wasn't. In fact, I usually has slightly better performance using the dipoles, which I think was due to the bulk of the max current portions of the antenna being higher above ground in general. The loop sagged a bit in areas, and wasn't all that high above ground. The more wire near the ground, the more ground loss in general. Mathematically it is proven that way also even tho both are in accordance to Maxwell's laws. Where is the math? You should find a very slight difference at best.. It's common knowledge that even a short piece of wire 1/10 of a wave long will radiate nearly all the power that is applied to it. You can go lots shorter than that if you want. If even a short piece of wire will radiate nearly all the power applied to it, what is the point on harping about some magical properties of a full wave length of wire? Art, you are starting to bark at the moon I'm afraid... I was going to comment on some of your other posts, but I think I'll spare you the increase in blood pressure. All I can say is that you are starting to wander off in mumbo jumbo land again.. Replacing known science with conjured mumbo jumbo is no way to live. MK Art, it distresses me to read the misleading statements you profess to be true in your posts. There is no difference in the 'efficiencies' between a full-wave and a half-wave dipole. Let's assume the wire size and conductivity of each dipole is such that we can say they both radiate 98 percent of the power delivered to them. Let's also say that the same amount of power is delivered to both dipoles. What now is the difference in the radiation between the two dipoles? snip Walt. I have no problem with Maxwells laws but I do have a problem with a mathematical stunt to measure radiation of a half wave dipole based on one having to accept that at all points on the radiator the current is sinosoidal. There is no distinct analysis with the specifics of radiation. period. Using a parallel circuity ala tank circuit insights are produced that radiation is created by the shorted energy containers of capacitance and inductance which is an intrinsic part of any radiator in distributed form. The tank circuit is well documented. So the question now becomes, at least for full understanding of radiation is how does a half wave radiator follow the format shown by a spark plug with a flyback transformer or a full wave radiator or even the blast from a nuclear bomb? Yes, a half wave antenna also has distributed inductance and capacitance energy containers but how is the mechanism shown by the tank circuit implimented when the arrangement is not in equilibrium? Now I think I know what happens but I am interested in contrary thoughts from those skilled in the arts without the retoric. As an aside, why does computor programs drift away from planar form radiators as well to full wave radiators when the computor is asked to compute for maximum gain? Is this like the quadratic equation with four answers where you get to determine the imaginary answers? I would suggest for starters those that are skilled in the art quantify the energy used for end effect radiation either in the normal atmosphere or in the rarified atmosphere of Quito Equador when Tesla type emmissions are visable? Without assumptions ofcourse!!!! Regards Art |
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