Honestly - these three antennas are probably far more complex than needed.
While the coils may help improve phasing and match impedance - the tolerances involved are very very very slim! Even a tiny error or variation in measurement is a huge difference with those designs at these frequencies.
At the height you’ll be placing the antenna, reception should be fantastic (assuming there is not RF interference from the workings of the windmill!)
Unless you’re very experienced with microwave antenna construction, I would stick to a groundplane spider, or “cantenna”
From this thread: ads-b-flight-tracking-f21/three-easy-diy-antennas-for-beginners-t20177.html
With the cantenna mounted inside my window, I was getting range of 120nm consistently.
Currently I have the FA antenna mounted on a pole basically at the roofline of my apartment outdoors, and the range is indeed better.
FlightAware sells a decent colinear outdoor antenna for $40 - for your application, if you can spare the cash, I think it may well be worth the cost simply for the weatherproof nature of the antenna.
If you can’t afford it, cant get it delivered to your location, or are simply adamant about building your own antenna, I suggest "cantenna in a jar"
I would definitely install a bandpass on your setup for two important reasons:
- The generator and switchgear inside the windmill definitely create near-field RF interference. The farther you can get your antenna away from them, the better.
- There is probably already an antenna on top of the windmill for remote control and monitoring, and from what I can tell these are usually cellular datalinks that will run on frequencies near ADS-B (GSM 900mhz seems common) unless filtered, this will have a serious impact on performance - and even with the filter, you’ll want your antenna as far away from the existing antenna as possible, (while also being as far away from the switchgear as possible. Might have to find a happy medium there)
Lastly, and this can’t be helped, you’ll have “RF Chop” on signals when the blades are spinning between your reciever and the aircraft, but this will only affect a part of the sky view, and probably won’t impact reception that badly.
Snap some photos when you get your setup going up there, if you can! very curious to see
best of luck.