On Thu, 10/20/16, Steven Dick <[email protected]> wrote: > The vertical loop can be horizontally polarized by feeding it in the middle > of the top or bottom edges. It can be vertically polarized by feeding it in > the middle of the vertical edges.
That's true for a loop having a full-wave circumference, but "Magnetic Loops" have circumferences that are typically only a fraction of a wavelength, and as such operate under a much different mechanism. A vertically oriented magnetic loop, regardless of where it is fed, will achieve the highest degree of coupling to a vertically polarized signal, and have a bi-directional (half-wave dipole-like) radiation pattern. A horizontally oriented magnetic loop, regardless of where it is fed, will achieve the highest degree of coupling to a horizontally polarized signal, and have an omni-directional radiation pattern. This is because a magnetic loop is most responsive to the magnetic component of the RF wave. When we speak of RF polarization, we are speaking of the polarization of the electric field. A vertically polarized signal will have a horizontally polarized magnetic field, and vice-versa. It is the horizontally polarized magnetic field from a vertically polarized wave front that will cut through the center of a vertically oriented magnetic loop and induce a voltage across its terminals. 73, de John, KD2BD ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
