Ads-b calculated range vs real range

hello, i’ve just made a simple calculation of my ideal ADS-B range based on my height and location… and i made a comparison with my actual range with the feeder. I noticed (pls see attached photos) that i see very very few aircrafts in the zone where teorically i should have the better range!! I also noticed that in that direction i have the house wall, maybe i need to change the antenna location? i actually can’t mount my small antenna on the roof of my house…


check this out :smiley:
[What is the Maximum Range I can Get?]


When checking theoretical range, take note that not only man made obstructions may reduce actual coverage, but also that trees can have a significant effect.

I used this guide. I think is the position of the antenna the problem (there is my house wall in the direction where I should achieve the maximum range). But I didn’t believe that a house can decrease significantly the range. Now I’ll try to put it in the garden to see if I can have some improvements







There doesn’t seem to be any calculation factor for tree density. :slight_smile:

abcd567 rulez :smiley:

For further reading, look at “Fresnel Zone”

For ‘better’ range prediction, try Radio Mobile
Radio Mobile

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Here is range plot by “Radio Mobile” technique at my location. It was not done by me. It was done by someone else (Martin) for me in Nov 2015.

That eHam thread is excellent. It can keep a person busy for a very long time.:grinning:

I was under the impression that a CoCo would be much better than a Cantenna. Not so, discarding all my CoCo files.:wink:

I once build a Jpole antenna for the 2M band using 300 Ohms twin lead TV cable. It worked great. Anybody tried it for ADS-B?

Looks like you have been at this for a very long time. A fantastic journey.


My bitter experiance with both the coaxial colliner, and wire collinears



November 2016

IMAGE 1 OF 4: J-Pole


IMAGE 2 OF 4: Super J-Pole


IMAGE 3 OF 4: Quick Spider


IMAGE 4 OF 4: Message Rate Graph

Thank you!!

I use a Flightaware and a ‘trimmed’ RTL dongle antenna.

I’ll try a spider and a cantenna.

very very useful reply. i think that my big problem is the house wall. I need to find a better position :frowning: