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![]() It's my opinion that as mentioned, only element static buildup might be reduced. And in most cases, that is usually only a problem in dry areas, sometimes in the winter during snow storms, etc.. Also at high altitudes, one example being HCJB using loop elements. Or they used to anyway. As far as any local noise that is received by the antenna, they should be the same as far as s/n. No difference at all. I'd almost be willing to bet that your case of lower received local noise is due to that antenna having better decoupling from the feed line than the one that seems noisier. Good decoupling is critical. If using coax, poor decoupling will allow noise that is picked up on the outer shield of the coax, to be piped back down to the receiver on the inside of the shield. That's pretty much the conclusion that I had stumbled my way to, after thinking about the question over the past few days. It's possible that the length of the feedline might be an issue. The impedance seen "looking down" the outside of the feedline coax could vary a lot depending on whether it happened to be closer to an odd or even number of electrical quarter-wavelengths. This could significantly affect the antenna system's overall pattern (a low Z along the braid would result in greater current flow and more RF radiation/pickup from the feedline). Adding some ferrites to the end of the feedline, just below the point of connection to the (noisy) dipole, might bring this antenna "to par" with the others. |
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