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Latest blog entry: Project Covert Ops: Long range ground...
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I hear you on the beliefs. I believe every bill in my wallet states "In God We Trust". -Alex |
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Latest blog entry: Project Covert Ops: Long range ground...
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Latest blog entry: Project Covert Ops: Long range ground...
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This is a circularly polarized antenna. it works best with other circularly polarized antennas. Linearly polarized antennas such as the Vee will experience a 3db polarization loss.
The bluppnik and turnstile are dual polarized. The caltrop is eliptically polarized. These all will match the helical fairly well, but not perfectly. These antennas were designed to work with both linear and circularly polarized antennas. The best match to the helical is the Skew-planar wheel. -Alex |
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Latest blog entry: Project Covert Ops: Long range ground...
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Beam witdth is inversely proportional to the gain and number of turns: 3 turns - 75 degrees 6 turns - 55 degrees 12 turns - 40 degrees -Alex |
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Latest blog entry: Project Covert Ops: Long range ground...
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Joined Mar 2009
185 Posts
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Yesterday I made my first fpv flight using your "v" antena design and it was perfect. Once again, thanks a lot sharing with us
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Currently in your tutorials is the skew-planar the only homebrew that is suitable to match this? I am interested in CP but I have not gone on with it mostly due to the problem of a durable TX antenna. To me the SP looks like something that I would destroy very rapidy, so I am hoping you have some alternatives in the works?
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Saint Louis, Missouri, US
Joined Sep 2010
139 Posts
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Wow Alex, great work! I hate to be the whiny guy, but could you post more/better pics of the #3 & #4 impedance matches (microstrip & conductor), especially how they are installed on the antenna? The Hecker transformer (I never knew it was called that) has been the only impedance match I've ever seen on a home-made helical before, so I'm really curious about these alternate methods. What exactly are you referring to as "height" in the calculations?
What do you think is the best material to use for the support brace? I have access to CNC-cut G10/FR4, but it looks like it has a significant dielectric constant and even adjusted for it there is ~>3dBi loss in gain. I'd like to use something CNC-cut, as the notches could be accurate to within a few hundredths of an inch. Maybe hobby plywood? Do you happen to know if adding a water-resistant coating like Thompson's WaterSeal will change the dielectric properties? Google had no love for me on that one. |
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As for the photos, I will post more after I build some more antennas. The camera memory card went bad on me when I tried to upload the photos. All of the antennas in the tutorial are on their way to Florida for testing. I plan on making a few more in the coming days for some beta testing. -Alex |
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Latest blog entry: Project Covert Ops: Long range ground...
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I fly a 1.3GHz skew planar wheel made from .030" mig welding wire. Despite numerous crashes, it still works great. I haven't broken it yet. -Alex |
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Latest blog entry: Project Covert Ops: Long range ground...
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