Towertalk
[Top] [All Lists]

## [TowerTalk] Delta (Quad) Loop Polarization

 To: [TowerTalk] Delta (Quad) Loop Polarization n4vi@arrl.net (Chris Adams) Mon, 10 Sep 2001 07:49:27 -0600
 ```Well it's certainly common to extract a non-H/V polarization into these components to do easy mathematical operations. The only reason it is legit to do these operations is that they are equivalent. 73 chris, n4vi Tom Rauch wrote: > > > I have modeled quad loops for dual polarization (H and V) and contrary > > to W8JI claims and others, they have dual polarization components > > nicely filling nulls in the pattern of the "other" polarization. I had > > 3 el. dual polarization quad mounted over salt water on the boat ramp, > > half wave up, 90% of the time beating 4 square over "salty beach > > sand." > > Hi Yuri, > > The reason you see that "dual polarization" is because Eznec only > considers the polarization as two pure distinct polarizations. > > When you have a tilted wave, it shows up as a mixture of V and H > even though it is actually a plane wave of one pure polarization. > > If you stood out in front of the antenna with a small antenna and > checked the radiation, what you would find is a peak at some angle > other than flat or vertical, and a perfect null 90 degrees from that tilt. > > The only way to get two distinct polarizations at the same time is > to excite two similar antennas mounted at right angles in the same > physical location with 90 degree phase shift, to mount a small loop > with a small complementary dipole running through the axis and > feed them both in phase, or to stagger two right-angle antennas 90 > degrees distance and feed them in phase. > > In those cases, you will generate a circular rotating wave. > > It is physically impossible to generate more than one polarization > in any given direction at the same time without doing one of the > above, and without a rotating wave (circular polarization). People > wrongly think it happens because modelling programs display > results as mixtures of pure V and pure H when the wave is actually > just skewed. 90 degrees from that skew the field is zero, so you > have a single polarized wave that is simply tilted. > > For example, a horizontal dipole has a perfectly horizontal electric > field broadside. As we move off towards the ends, the wave starts > to "tilt". Straight off the ends, the electric field is vertical. But it has > ONLY one polarization in any point in space looking back at the > antenna. A loop is no different, neither is a Carolina Windom, > neither are a vertical and dipole that are centered and fed in-phase. > > 73, Tom W8JI > W8JI@contesting.com > > List Sponsored by AN Wireless: AN Wireless handles Rohn tower systems, > Trylon Titan towers, coax, hardline and more. Also check out our self > supporting towers up to 96 feet for under \$1500!! http://www.anwireless.com > > ----- > FAQ on WWW: http://www.contesting.com/FAQ/towertalk > Submissions: towertalk@contesting.com > Administrative requests: towertalk-REQUEST@contesting.com > Problems: owner-towertalk@contesting.com List Sponsored by AN Wireless: AN Wireless handles Rohn tower systems, Trylon Titan towers, coax, hardline and more. Also check out our self supporting towers up to 96 feet for under \$1500!! http://www.anwireless.com ----- FAQ on WWW: http://www.contesting.com/FAQ/towertalk Submissions: towertalk@contesting.com Administrative requests: towertalk-REQUEST@contesting.com Problems: owner-towertalk@contesting.com ```
 Current Thread [TowerTalk] Delta (Quad) Loop Polarization, K3BU@aol.com [TowerTalk] Delta (Quad) Loop Polarization, Tom Rauch [TowerTalk] Delta (Quad) Loop Polarization, Chris Adams <= R: [TowerTalk] Delta Loop, GianLuca Salvia [TowerTalk] Delta Loop, Tim Makins, EI8IC [TowerTalk] Delta (Quad) Loop Polarization, Tom Rauch