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![]() "Richard" wrote in message ... A turnstile is a horizontally polarized antenna. Big downer is that from a polar radiation POV, from the sides, it's got a minus figure. Like -2db or something. I'd call it 'circular' polarization... but OK... Okay, flipp the turnstile so you have one dipole vertical. Not a turnstle anymore, and the element configuration will respond favourably to both vertical and horizontal radiation. What happened to the ground plane when you did that? Is one element touching it now? The antenna will have a bi-directional pattern unless you include the plane to work against (not necessarily bad...). But: 1) Do you have to wire up the "flipped turnstle" in a different way in order, at the same time, (without any switching) to take advantage of: a) mixed polarized waves? b) vertical or horizontal waves? The only time circular is a disadvantage is when the incoming wave is circular, and opposite to what you're receiving. 2) If you put up a "flipped turstile" and you wire it up to handle mixed, vertical or horizontal waves, what is the polar radiation patter in the horizontal plane (ie from the sides) ? Still a minus? It'd be a null... about like a dipole of that polarity (I'm guessing...). Amhoping that a "flipped turnstile" properly wired would perform with mixed, vertical or horizontal waves coming from the sides. And hoping better than a turnstile. An interesting array might be a XYZ affair, three crossed dipoles. Switchable to choose the best axis to null. __ Steve KI5YG .. |
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Help with 900Mhz turnstile.... | Antenna |