I have just built an antenna that I modelled on Eznec pro. Model shows 9.14dBi gain at just above horizon. Testing on my dining room table indoors on dump1090 I am getting aircraft 432kms away.
Next test will be to put it at correct height. Its not an antenna currently in use for ads-b.
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what style or design of antenna did you build?
I’m still experimenting, modelling and testing. So far the antenna does not like height, so difficult to get it above the buildings. It also has nulls where I get no data so now I am playing with additional passive elements.
Elevation plot and swr graph of my new antenna
Will be building the prototype this week.
Has a small resonant bandwidth, so should not be noisy.
Will be about fifteen inches (38cm) high and about six inches (15cm) wide. Mount height modelled is 19.68 feet (6m).
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I cut my antenna original 11,6 cm to 5,2 cm, has shown, but the range down several miles. With the length original my range get many varieties and far. 
Did you place the mag-mount whip on a metallic (preferably iron/steel) plate or food-can to provide a ground-plane?
Cutting the whip to optimum length is not enough, unless a ground-plane is also provided.
A metal surface I noticed did not change the range and quantity of varieties.
Then I will make a copper iron as a 13.5cm rod, a length that should be close to ideal, as it has the speed factor of the medium of the material
Obter o Outlook para Android
As a note for beginners freaking out about having totally correct parameters. I have 2 stations, 1 with a perfectly tuned 5/8 colinear antenna driving my main receiver, and then a secondary receiver (backup and experimental) with a little 1/4 spider antenna under a radome. I live in a valley, so antennas are not really range limiting for me, but I still receive aircraft in the N/S direction to around 200nm. This weekend we had another storm, and I only noticed today that the radome on the 1/4 antenna is gone, and I guess the stub of the radiator is bent over,as I can’t see it from the ground. On graphs 1090 I can just see a small dip… would never even have noticed it if I didn’t look up at the mast. Still get 200nm on it, but I guess I see maybe 1 or 2 fewer aircraft. Have to wait until all the snow and ice is gone before I pull down the mast and do maintenance on the antennas, but yeah, totally surprised I still get a nice performance from a totally destroyed antenna. (It does feed a filtered LNB at the top of the mast).
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This is 2015 information, which is no more valid as now Flightaware Antenna is not available at Amazon. Now it is available at Flightaware Store:
If you are living in Europe, you can also get the Jetvision antenna in their store. Flightaware is delivering this antenna for their own receivers.
The assembly is very good. I would still use it if i didn’t buy one from Vinnant
For these antennas which have a little spiral (pigtail) in the middle of the whip, how do you measure the 67mm for the whip? From the base or from the (top or bottom) of the spiral?
Do NOT cut such antenna. These are custom design. Cutting whip may result in substantial reduction in performance.
Cutting whip is recommended for straight whip only.
You can try following without damaging the whip:
Do NOT cut the whip. Unscrew it, and use a thin wire as whip. You may use a thin steel tie wire or one of the wires in a scrap network cable.
If the wire is thin, it will be easy to wrap it over the threaded brass stud of the magnetic base. With thick wire it is a bit difficult.
Thank you.
Why 52mm, shouldn’t it be 67mm?
Because 15 mm length is hidden inside base.
Total length = 52mm + 15mm = 67mm
Please see sketch below.
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For folks that are building their own antenna, wanted to share my experience building one.
I initially built one based on the recommendation at the start of this thread. 69mm for the vertical element and 69mm for the 4 elements bent at 45 degrees. It was working better than the antenna I got with the SDR but was still limited to about 50 nautical miles. I looked around and found several different calculators. Some accounted for velocity factors some accounted for the thickness of the element and these antennas were much better and able to see flights about 100 NMiles away. However, they measured the length of the bent elements differently. Some included the base radius while others didn’t.
Continuing my search for a better design I stumbled across this site. It has a very clear description of how to calculate the lengths. I built my current antenna using these measurements and now can see flights over 250 N miles.
I have the antenna installed in my attic on a 10 foot pvc pipe 
I am happy with the results.
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Hey now! That’s not always true! Already being a die-hard aviation enthusiast and gadget aficionado when a buddy first told me about FlightAware, I built my first PiAware with the 66cm/26in Indoor/Outdoor 1090 MHz Antenna from FA’s Amazon store. I hi-jacked an retired Dish Network 2" pole that was already ascending about 16’ to clear the roof at our family’s business and I re-pulled a nice and short RG-6 coax drop to replace what had been there for probably 10+ years. I can pick up traffic at 160-200nm but that’s my reasonable limit with my current setup.
I would be less than honest if I didn’t say I’ve had more than one brainstorming session of friends/family/former co-workers who have strategic geographic locations that wouldn’t mind letting me mount my second PiAware setup in another place I’d be passionate about covering.
Best wishes,
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I managed to build an 11 element collinear, from RG-6 solid core. I carefully measured each of the elements, inserted it inside a pvc pipe. I swept it with the nanovna, and found it was really close. A couple preamps, the FlightAware filter and I hoisted the whole think up 70’ into the pine trees. I have reliable tracks out to the 200nm range ring… I typically average during the day 250 a/c… I’ve yet to hit 300, almost one Christmas Eve though… Don’t be put off, try the collinear, used in commercial communications, the good old Station-Master used to be the mainstay for repeaters and public service. I took a lightning struck antenna apart, and sure enough; collinear, made with tubing and braided wire…
73 all
wb7ond
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I have made so far 3 spider antennas all with 4 legs (for simplicity) and what I noticed is that the orientation of the antenna greatly affects its reception. What I mean is not if the antenna is vertical, which is obvious, but the orientation of its legs. So you need to turn the antenna on the horizontal level and watch how much this affects the signal and received planes. From experience if I want to detect as much planes as possible, I have to check their routes on a map and then rotate the antenna in a such a way so some of the legs face these routes. I’m talking mostly for planes that are far away and high, the planes closer to me (I live very close to an airport) are detected more or less no matter what the orientation is. It’s a good antenna and very easy to be made but obviously it’s reception lobes are limited and very selective even though it’s not a directional antenna. Maybe more legs will minimize the need for specific orientation.
What’s your opinion and experience ?