Friends, I need some help. I had some problems with my old Pi, and had to replace it. I used the same memory card. However, now I’m getting terrible results in my reception, where I can’t get more than , where 15/30 before reached 50/70NM. With that, I would like to check what I can do to try to improve my range or if I am having any other type of problem, either with the antenna or my ADS-B receiver
Antenna: Jetvision A3 ADS-B Antenna 1090 MHz
Receiver: RTL-SDR V3
Raspberry: PI 3 - Model B
The antenna is positioned over an open area.
My receiver details:
root@raspberrypi:~# rtl_test -t
Found 1 device(s):
0: Realtek, RTL2838UHIDIR, SN: 00001090
Using device 0: Generic RTL2832U OEM
Detached kernel driver
Found Rafael Micro R820T tuner
Supported gain values (29) 3.4 43.9 44.5 48.0 49.6
[R82XX] PLL not locked!
Sampling at 2048000 S/s.
No E4000 tuner found, aborting.
Reattached kernel driver
I have already changed dump1090-fa to dump1090-mutability
My stats - philippi ADS-B Feeder Statistics - FlightAware
Anyway, I don’t know what else to do, and I’m getting frustrated by the low efficiency of my station.
First of all I would leave dump1090 mutability since that is no longer maintained.
Reinstall dump1090-fa and the latest version of piaware.
Then activate adaptive dynamic gain (check the posts in the forum) and let that run for a day or 2 to see if that improves your reception and range
3 Likes
Thanks for your response.
I returned to dump1090-fa, reinstalled piaware, there was a slight improvement, but still nothing as acceptable. I don’t know if my route is little visited, or if I’m really suffering from some problem that I can’t identify.
1 Like
Install graphs1090 on your system so you can see visually what is happening to it and where the issues might be.
Maybe the reciever is flooded with strong messages and this might lead to a lower reception range.
By using the program you can identify a number of things and work from there on to improve the reception again.
1 Like
Did you cut out the stuff from that output?
Should look like this:
Found Rafael Micro R820T tuner
Supported gain values (29): 0.0 0.9 1.4 2.7 3.7 7.7 8.7 12.5 14.4 15.7 16.6 19.7 20.7 22.9 25.4 28.0 29.7 32.8 33.8 36.4 37.2 38.6 40.2 42.1 43.4 43.9 44.5 48.0 49.6
[R82XX] PLL not locked!
In general there can be many issues that can cause something like this.
The new pi is using an original RPi power supply? That can be important.
Using an USB extension? That can also cause issues.
Usually SDRs that are specialized for 1090 MHz (with LNA and filter) will get you better reception.
Examples of those are the FA Pro Plus (availability is a bit complicated) or a similar one from adsbexchange (https://www.amazon.com/ADSBexchange-com-RTL2832U-Antenna-Software-Industrial/dp/B09F2ND4R6)
Maybe the coax is loose?
Possibly moisture in the coax or antenna (that usually shows up gradually though and not from one day to the other).
If you have bad luck, can also be the SDR is just going bad.
1 Like
Hi, thank you for your response
Below is the complete rtl_test file
root@raspberrypi:~# rtl_test -t
Found 1 device(s):
0: Realtek, RTL2838UHIDIR, SN: 00001090
Using device 0: Generic RTL2832U OEM
Found Rafael Micro R820T tuner
Supported gain values (29) 3.4 43.9 44.5 48.0 49.6
[R82XX] PLL not locked!
Sampling at 2048000 S/s.
No E4000 tuner found, aborting.
I also installed graph1090, although the results don’t tell me much
https://cathartic-lizard-7381.dataplicity.io/graphs1090/
I’m using an original Raspberry charger, but I’ve already made the switch without any major changes.
No USB extensions
Coaxial cable ok, I even removed the protections and renewed it again with insulating tape.
Anyway, as I only have one USB dongle, I will be purchasing another one to check the results.
1 Like
I looked at both of your links and your positions by distance is extremely limited which you already know. What antenna are you using? Your gain seems too hot to me. I would drop back 10 points to start with. So many possibilities. How high is your antenna? Is it above the peak of the house if that’s where you are mounted.
1 Like
Forgot to ask what coax are you using? Is it a 50 ohm coax for starters? Hopefully a 240 or 400 series coax.
1 Like
My antenna is a Jetvision SCO-1090-GPS with a 10 meter 50 ohm cable
and is located high above my house with a clear view of the sky, although I live in a valley, and have received receptions at 80-100nm
I’ll try reducing the gain a little and see.
1 Like
Looking at your test results and the graphs my suspicion would be that your dongle is dying.
The limited set of gain results is strange as Wiedehopf stated.
Do you have a spare dongle to test with?
A max gain of 58.6 dB is normal for a RTL-SDR v3 dongle as being the value.
This equals AGC or the 49.6dB that is seen on a FA Pro stick dongle.
4 Likes
They show that you are receiving very low signal levels, even though you have a high gain setting. Given the strange gain value response from your dongle, I would suspect that the dongle is failing. It could however be an antenna or coax fault.
2 Likes
I ordered a new dongle, which should take a few days to arrive. As soon as it is in hand, I will carry out further tests. I thank everyone for the help.
4 Likes
Good news guys.
After exchanging the dongle for one from FlightAware, the problem was resolved and we once again had good statistics. I appreciate everyone’s help in detecting the problem.
You can lock the topic
4 Likes
