Hi, How is it possible that my 68mm antenna picks up a aircraft 400+km away?
On 1090Mhz, my VHF radio cant pick up that far without a yagi?
Thanks
Evan
It’s mostly a question of whether you have line of sight or not. For an aircraft at 40000ft, you’ll have line of sight out to a little under 400km; refraction will stretch your range some more. It’s also a digital mode which is fairly tolerant of noise - you need less than a miliisecond of clear reception to pick up an ADS-B position message.
Hi
Since I have you here.
So I made one of those vertical with legs, 67mm etc.
I'm using rg58 quite a length, so alot of loss i reckon, into my pi zero and rtl receiver.
antenna about 7m off the ground. In last 24 hrs, <80 thats 4500, 80-160 thats 66, and then miraculously 400+ I get 4.
I'm not using filters etc, what should I be doing to improve my radiation pattern and ads-b collection.
Thanks
Evan
"Seligs"
Hi Evan
First determine what is the maximum range you can get by the method given in the post linked below. This will act as a benchmark, and enable you to see how much room is there for improvement.