“Any work which does not meet all these requirements will require planning permission.”
Fortunately, some councils look at individual cases and apply common sense. I don’t have planning permission (and under the seven year rule, I now don’t need it).
Nicely done! “Grandfathered in”.
As far as i know it is nation wide. But i did not read all the laws and regulations but as far as i see any antenna pole above 10 Meter in total (including the antenna) needs to be approved.
But some also wrote that this is valid for poles mounted on a roof also. In this case you can build it as long as it does not exceed the 10 meter or the roof top line (what reached first). I am trying to find a readable document somewhere
Whenever one of the two parameters are exceeded, you need a license for it.
In case you just want to catch aircraft, getting the license is not that easy, because you need also a plan for your “Bauvorhaben” (construction project), most of them are only approved in case of a mobile network device. You have a better chance if your antenna can be built on such an already existing pole.
Beside that there a chance of getting in trouble with the neighbor. Some people here don’t like it if there is something going on they don’t know/understand.
Not a problem at all, but not the best option for a good neighbor relationship.
Beeing close to an airport is normally not a problem at all, because it all falls under that 10 Meter agreement.
If you want to go higher, you need the approval and they will clearly check this also against the airport traffic if needed.
But i am really not an expert, there are too many documents to read here. I did not do that in detail as my antenna would never exceed the 10 Meter
But beside that i would not go that high, lightning strikes are not a one-in-a-million event here.
For reference, that antenna has dimensions for the 2m amateur band (146MHz).
You can scale it to get something workable on 1090MHz, but you will discover RF theory has a certain element of black magic (translates to: things don’t always work as you’d expect)
Thank you, I found it and order from Aliexpress.
I don’t think so. I am simply limited by the terrain. If i compare the max range (heywhatsthat) to the range i achieve, it’s pretty much the same. I only have a blind spot with shorter range because my own roof blocks it in this direction.
What you see here is also an issue of the cable and not only of the antenna.
By the way …just for your information
I have optimized my patch antenna and it looks now like this …see the link
The antenna is calculated, simulated …transfered to the real world
Very near to how the ideal ADS-B antenna has to be.
The most interesting thing here is that this antenna is able to receive very high altitude objects > 60000 ft, it is independent to polarization effects and generate a higher resolution frames/sec. The antenna has to be used as a sector antenna means the front beam generate maximum range, the back beam generates max. 300 km
The antenna can be used in horizontal or vertical (sector) orientation.
thank you very much for your attention
…if you need a 50m pole for LoS (line of sight) you are right.
If you have LoS a 50m pole will generate maybe 25km more range max.
Such literal reactions. Lighten up, folks 
so …open speaking if you have LoS it make not so much sense
Yeah towers are the way to go only if your obstacles are closer than maybe 1 or 2 miles.
The closer the obstacles the greater the benefit.
The benefit is minimal if the obstacles are much higher than the tower you’re going to build.
Hello Folks, new here but I have a question that is tricky to me:
I have a length of rg6 cable, 75 ohm impedance, connected to a nesdr smart, which is 50 ohm input impedance.
Which one have less loss, a 50 ohm antenna or a 75 ohm antenna?
Thanks in advance.
Hello, @PA1NT .
this 2250message/second includes S and AC mode?
A 50 ohm coax and antenna will have the least loss as their impedance matches that of your SDR dongle’s antenna connector. That being said, the slight loss due to the impedance mismatch between your 50 ohm SDR and 75 ohm RG6 coax is negligible.
Particular antenna designs* have whatever impedance they have, whether it be 50 ohms, 75 ohms, 300 ohms or whatever and it’s up to the individual to provide a matching circuit such as a balun to match the impedance of their feedline to that of the antenna.
*I’m talking about antennas in general, not just ADS-B antennas (before all the pedants here start trying to correct me.)
Thanks @jaymot
I have in my mind the analogy with pipes (I may be wrong, very wrong), but I guess one mismatch (antenna 75, cable 75, input 50) is better than 2 (antenna 50, cable 75, input 50).
Anyway, I am about to try both scenarios by myself.
Thanks again!
