anything
AirNav RadarBox
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with username, password and session length
 


Author Topic: Range display and feeder issue  (Read 280 times)

0 Members and 1 Guest are viewing this topic.

supashot

  • New Member
  • *
  • Posts: 3
Range display and feeder issue
« on: August 17, 2021, 04:33:02 PM »
hi,

I feed for years (Raspberry Pi 4 Model B Rev 1.4, RTL-SDR RTL2832U DVB-T Tuner Dongles, RTL-SDR Blog ADS-B Triple Filtered LNA (Bias Tee Powered), and high quality coax)and noticed for the past days that I cannot see my range displayed on the map.
My stats profile shows adsb 30,37.
I ssh to see the status:
sudo systemctl status rbfeeder
rbfeeder.service - RBFeeder Service
   Loaded: loaded (/lib/systemd/system/rbfeeder.service; enabled; vendor preset: enabled)
   Active: active (running) since Tue 2021-08-17 15:17:20 UTC; 50min ago
 Main PID: 563 (rbfeeder)
    Tasks: 11 (limit: 4915)
   CGroup: /system.slice/rbfeeder.service
           └─563 /usr/bin/rbfeeder

Aug 17 16:06:59 piaware rbfeeder[563]: [2021-08-17 16:06:59]  Can't connect to 978 source (127.0.0.1:28380). Waiting 5 second...
Aug 17 16:07:04 piaware rbfeeder[563]: [2021-08-17 16:07:04]  Can't connect to 978 source (127.0.0.1:28380). Waiting 5 second...
Aug 17 16:07:05 piaware rbfeeder[563]: [2021-08-17 16:07:05]  ******** Statistics updated every 30 seconds ********
Aug 17 16:07:05 piaware rbfeeder[563]: [2021-08-17 16:07:05]  Packets sent in the last 30 seconds: 7, Total packets sent since startup: 374
Aug 17 16:07:05 piaware rbfeeder[563]: [2021-08-17 16:07:05]  Data sent: 17.3 KB
Aug 17 16:07:05 piaware rbfeeder[563]: [2021-08-17 16:07:05]  Data received: 1.3 KB
Aug 17 16:07:09 piaware rbfeeder[563]: [2021-08-17 16:07:09]  Can't connect to 978 source (127.0.0.1:28380). Waiting 5 second...
Aug 17 16:07:14 piaware rbfeeder[563]: [2021-08-17 16:07:14]  Can't connect to 978 source (127.0.0.1:28380). Waiting 5 second...

See likes up and running? Am I missing something ?

I also feed for flightaware, I noticed also almost no feed.
Any reason why I would be able to track very few? I just added a 1090 filter, no coax (that worked fine and gave an an amazing range.)

In RB24 my last tracked plane is 3A28AC EUROCOPT 2021-08-17 07:07

I email the support but any help or hints would be appreciated.


UPDATE: went to check the 20m cable, all the connections are ok, no water in the antenna. I still don't understand how it went from 90 planes per days to almost nothing.


Update august 18th: Big detail I missed when I connected the ADS-B Filter https://www.aliexpress.com/item/32956847941.html : RTL-SDR V3 has bias tee power built into it and this can be activated in software
Please note that this LNA FILTER requires bias tee power to work.

I use the official RTL-SDR SDR V3 R820T2 RTL2832U: https://www.aliexpress.com/item/32939551915.html


So to get the filter to work we need to enable Bias tee on the usb stick, this can be by software in V3, I run PiAware 5.*
To enable it:
cd ~
git clone https://github.com/rtlsdrblog/rtl_biast
cd rtl_biast
mkdir build
cd build
cmake .. -DDETACH_KERNEL_DRIVER=ON make


To test the bias tee:  sudo service dump1090-fa stop && cd ~/rtl_biast/build/src && ./rtl_biast -b 1 && sudo service dump1090-fa start

You should get something like that:
Found 1 device(s):
  0:  Realtek, RTL2838UHIDIR, SN: 00000001

Using device 0: Generic RTL2832U OEM
Detached kernel driver
Found Rafael Micro R820T tuner
Reattached kernel driver

To get Bias enable every time you reboot you MUST add the following:

sudo mkdir /etc/systemd/system/dump1090-fa.service.d
sudo nano /etc/systemd/system/dump1090-fa.service.d/bias-t.conf
 
Then paste in the following

[Service] ExecStartPre=/home/pi/rtl_biast/build/src/rtl_biast -b 1



My Raspeberry is connected to the USB stick that is connected to the filter then to the antenna 15m away.

Now it kinda work: the antenna is in the same position and I have some strange tiny corridors with a max coverage up to 52nm instead of 89 nm 2 weeks ago. While is used to be a clean radius, and yes nothing changed around the antenna( no new build etc...).

I feed for RadarBox, FlightAware, FlighRadar24 I now see some light traffic (night here only few cargo plane).

What is strange is that it worked out of box with a range of 89NM and stopped few days ago with unknown reasons when I first connected the filter. Went from 50nm to 90nm in few minutes after connecting the filter and a new thick coax, then gone.

I would HIGHLY recommend https://github.com/wiedehopf/graphs1090 that helps to get detailed stats live on my system, it should be installed by everyone very useful to debug with live data when loosing a feed. Easy to install and live.


Remark: I compared the range on all my feeds, none are the same! Flightaware shows me planes up to 160 km up, RB up to 107km, and FR up to 100km.
FR android app show a lower range than the web interface about 90km.
« Last Edit: August 18, 2021, 03:40:22 PM by supashot »

Runway 31

  • Moderator
  • Hero Member
  • *****
  • Posts: 31050
Re: Range display and feeder issue
« Reply #1 on: August 18, 2021, 02:27:52 PM »
Are you getting anything throught the flightaware feed?

Alan

supashot

  • New Member
  • *
  • Posts: 3
Re: Range display and feeder issue
« Reply #2 on: August 18, 2021, 03:41:56 PM »
Yes, I updated the post with details to avoid confusion. It kinda work again except that I still have a lower range, almost 50% lower.

Runway 31

  • Moderator
  • Hero Member
  • *****
  • Posts: 31050
Re: Range display and feeder issue
« Reply #3 on: August 18, 2021, 04:30:41 PM »
If the LNA is filtered will that not interfere with the new filter, have you tried removing the new filter it to see if the range improves.  Using Wiedehopf's graphs is very sensible for anyone using a Pi

What is your RB feed number?

Alan

supashot

  • New Member
  • *
  • Posts: 3
Re: Range display and feeder issue
« Reply #4 on: August 19, 2021, 08:56:14 AM »
hi Alan,


I tried removing the filter, I spent the past 48h to try all combination, Software activation of Bias Tee was a MUST to get the LNA working properly. I saw few posts saying tracking sometimes was worst than with with filter, it was mainly because Bias Tee was not activated.

Latest update: for station EXTRPI023778 range now shows up with better than anytime before: about 145 NM instead of the poor 52 NM.

I still don't understand why it worked before even if the bias tee was not activated.


Now all is good and remember to activate Bias Tee when using those LNA filter and this USB device.

Runway 31

  • Moderator
  • Hero Member
  • *****
  • Posts: 31050
Re: Range display and feeder issue
« Reply #5 on: August 19, 2021, 10:50:51 AM »
Good advice and thanks for sharing

Alan