FlightAware Discussions

Coaxial Collinear Antenna : My experiences!

Hello All,
It has been quite sometime now, (an year to be precise) with the ADSB tracking and all the related stuff. In a place like India where ADSB tracking is not as popular as in the western countries like the US and the Europe, it is always difficult to find people with the know-how on technology like ADSB and even more difficult to implement it by self. But thanks to the great team at FlightAware who have always been at help whenever required and of course to some of the resources on the internet.

Now coming to the point, I have been hosting a flightfeeder at my place for a year, but after a few months I observed that the number of aircrafts tracked and the messages received had fallen down significantly.
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Initially I suspected a bad connection and tried troubleshooting with the FA support but unfortunately it did not still work. It was really kind of FA to send me a replacement antenna but even that did not work and the tracking data went further worse. At last, I decided to give a last go before I thought of quitting and surprisingly the coaxial collinear antenna came to rescue with such impressive results. I am satisfied with the coverage and I think anyone facing similar issues must give it a try. It is really cheap and easy to build, but you get impressive results. The one I built could surely have been improvised further but this is all that I could build with my limited knowledge and expertise with antenna. Finally my new antenna is installed and is feeding to Flight Aware.
My Antenna while I built it:


Outdoor Installation:

Enhanced coverage (around 100NM and above):

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My Site - https://uk.flightaware.com/adsb/stats/user/nishantkumarrai23#stats-87214

I would like to thanks @MatthewH2 from FA support for all his troubleshooting help!

If you are using a new cable with the colinear antenna, then i would bet that the cable you were using with the FA antenna got damaged.

Anyway you are covering a good stretch of land, congratulations on a successful antenna build!

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Thanks! :slight_smile:

DIY coaxial collinear antenna is a “Shot in the dark”.
In few cases it may be a hit, but mostly it is a miss.

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Well if that is true, then I must say I was lucky enough in my first attempt! But it is something that must be given a try before going for commercially available antennae. You may end up making one with a little money and have great results!! :blush:

I don’t want to discourage you, but most of the time the FA antenna provides better coverage compared to what you have.
I’d say even a simple quarter wave quick spider can provide similar, if not better results.

The bad performance you experienced from the FA antenna was most likely as i said a cable defect.

Maybe just try making a quick spider:
QUICK SPIDER - No Soldering, No Connector

Will be a good comparison and should be easy after making the colinear antenna :slight_smile:

You might also be interested to check how terrain affects your reception:
What is the Maximum Range I can Get?

Will surely try making the ‘spidy’ whenever I get some time. And thanks for sharing that DIY post. Will be posting my results on the forum once I am done and have installed it. :slight_smile:

Substitution is an excellent diagnostic tool. What you have demonstrated is that the antenna is not the problem.

Looking at your location, elevated antenna position and the performance of your “Nearby Sites”, I think you have a lot of room for improvement.

Unless you have some local obstructions, your coverage should approach this:

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Oh! that was an eye-opener :slight_smile: . I think I can still work on to get the coverage to the maximum. Just want to know if trees can be a hindrance to the ADSB signals? Can you explain what the yellow and blue boundaries mean in the above image?

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This answeres your question: