SDR Raspberry pi, mounted remote at antenna?

[delta_charlie]

Hi all, I had just got back from my morning run and was looking at my discone antenna when the thought came to mind why not shorten the cable (reduce loss) and setup and mount a SDR Raspberry pi combo next to the mast. Then I should be able to access the Raspberry pi by WIFI and not have the coax cable running into the house. This time of year we get lots of bad lightning storms and I really do not feel comfortable with the coax being next to the kitchen. I felt uneasy enough that I pulled the cable out and coiled it up at the mast.

Anybody played around with SDR on a Raspberry pi?

Going to have to look into this some more.

 

[Magic Static]

There's a long thread by fred555 where he uses a raspberry pi with a DVB tuner to wifi the signals from the dish. A interesting project for sure.

 

[delta_charlie]

Update - just got the first big step done. Headless Raspberry pi 3+. I do not have a HDMI monitor, only the TV so I thought the first thing to do would be to try and set the Raspberry up as headless and that's how I plan to use it at the antenna so why not start there.

Headless Raspberry setup is well documented online so I won't go into details but it is quite extincting to see a new mac show up in the router (it's alive!)

Had a little trouble figuring out the ip to ssh to because I could not find the ip in the router, just the mac. Found the ip for my desktop and TV and with a little guessing, started to make progress. Did have a little login issue but got the command in the screen shot to work.

Next step will be to try and get a remote desktop working. Should be a fun and interesting project. Stay tuned

 

[KE4EST]

Very nice! I open the picture and tried to "ls", but that didn't work.

 

[delta_charlie]

Long story short, my original thinking was to run Gqrx on the Raspberry pi and use remote desktop to view the display. Almost got it working but hanging at an audio error when I ran across a web page that had a completely different approach. Run the client on the desktop and access the Raspberry/SDR dongle over tcp/ip. Got to read up more on this as it may be a much better way to go.

Setting up Gqrx Software Defined Radio on Ubuntu 18.04 Using Remote Raspberry Pi SDR with rtl_tcp

The picture show the link above displayed on my desktop from the Raspberry using remote desktop.

 

[Inclined Orbit]

Computer cables like USB can carry RFI on the outside shield, so if you remote a Pi at the antenna you might want to use the recommended mix of ferrite and number of turns for the USB cable or whatever you will used to control the Pi. Otherwise I tried a Raspberry Pi 4 with an RSP2pro SDR and didn't like the GUI that much compared to the Windoz version. The Pi 4 ran ok but an earlier test with a Pi 3 was not so good, the Pi 3 ran out of poop.

 

[KE4EST]

I lost interest in the Rpi4 after I discovered the Nvidia Jetson Nano and Xaviar NX.

 

[delta_charlie]

Computer cables like USB can carry RFI on the outside shield, so if you remote a Pi at the antenna you might want to use the recommended mix of ferrite and number of turns for the USB cable or whatever you will used to control the Pi. Otherwise I tried a Raspberry Pi 4 with an RSP2pro SDR and didn't like the GUI that much compared to the Windoz version. The Pi 4 ran ok but an earlier test with a Pi 3 was not so good, the Pi 3 ran out of poop.

The goal is to access the Raspberry at the antenna using WIFI with no wires other then power. Might even try using a 12 volt battery instead of using mains power.

Running Debian Linux 10 (Buster) on the desktop so the Windoz version would not work for me.

 

[delta_charlie]

Woo-Hoo ! It's working

Have the Raspberry PI 3+ on the floor using the built in WIFI hooked up to a NooElec R820T SDR. Using only a jumper as an antenna pulling in a local FM station.

The client program is running on the Desktop using TCP to connect and control the Raspberry. Here are a few screen shots:

 

[delta_charlie]

Setting the Raspberry up this way does not require for it to run the X-server (display manager) so I decided to free up some memory on the little Raspberry.

First screenshot shows the stats running X-server and playing a FM radio station.

Second shows the stats after disabling the X-server.
Looks like it did free up a good bit of memory.

From the history command:
98 command used to disable X-server
101 command used to start TCP after reboot
------------------------------
Here are a few notes that may help someone that might want to give this a go.
81 sudo apt install gqrx (this is obsolete)
82 sudo apt install gqrx-sdr (use this instead)
---
90 rtl_tcp -a 192.168.0.7 & (start TCP)
91 netstat -a | grep 1234 (test TCP)
---
95 uptime
96 vcgencmd measure_temp (check running temp)
97 free -b -h (check memory)
98 sudo update-rc.d lightdm disable (disable X-server)

 

[delta_charlie]

It's picking up the WX station with a jumper for an antenna. It's going to really start to find stuff when I hook it up to the discone. Being able to shorten the coax should help on the high frequencies (less loss).

 

[KE4EST]

This is great work!

 

[delta_charlie]

This is great work!

Thanks, now that I have it working really well I think I may go back and burn a new SD card with Raspberry Pi OS (32-bit) Lite (no desktop display) and make a step by step how to. (just the tricky part of Gqrx on the desktop and the driver for the USB dongle.) Everything else on the Raspberry is already well documented online.

 

[delta_charlie]

Just mounted the Raspberry at the Discone antenna, really pulling in the signals now. I cut a piece of scrap chip board to fit on top of the bracket holding the antenna mask just under the roof eave (should be a nice dry place). Check out the roll of coax I was able to cut out, will reduce loss on the higher frequencies.

It's now able to run FM wide in stereo with excellent sound on the desktop computer. I was also able to pickup a WX station based out of Melbourne Fl, on the screen shot below the red line is the local Orlando WX the right line is the Melbourne WX I see some others there too.

I went back and burned a new SD card with the Raspberry Pi OS (32-bit) Lite image and set it up to run headless. The little Raspberry Pi is very responsive with the minimal OS and it is amazing how little it takes to get it going. Check out the screen shots below.

 

[Art7220]

So, is it online? They do have SDR online you can listen to.
This is the only way to get WWV streaming.

http://websdr1.sdrutah.org:8901/index1a.html?tune=5000

 

[Scott Greczkowski]

So, is it online? They do have SDR online you can listen to.
This is the only way to get WWV streaming.

http://websdr1.sdrutah.org:8901/index1a.html?tune=5000

I love listening to these. Here is a better list of them.

Wideband shortwave radio receiver map

 

[kshaw]

Hi all, I had just got back from my morning run and was looking at my discone antenna when the thought came to mind why not shorten the cable (reduce loss) and setup and mount a SDR Raspberry pi combo next to the mast. Then I should be able to access the Raspberry pi by WIFI and not have the coax cable running into the house. This time of year we get lots of bad lightning storms and I really do not feel comfortable with the coax being next to the kitchen. I felt uneasy enough that I pulled the cable out and coiled it up at the mast.

Anybody played around with SDR on a Raspberry pi?

Going to have to look into this some more.

I have built several Stratux ADS-B receivers for pilots which are built on a Raspberry PI 3 or 4 with two tuners. These recieve weather radar and aircraft traffic from FAA towers and broadcast this information via WiFi to an IPad. The Pi''s with builtin WiFi SDR are more reliable than the ones using the WiFi dongles. Mine also has a GPS chip for location services.

 

[harshness]

Of course since you can't typically get your hands on a full-sized Raspberry Pi, it is all kind of academic in 2022.

 

[KE4EST]

Of course since you can't typically get your hands on a full-sized Raspberry Pi, it is all kind of academic in 2022.

Plenty of ARM based SBC's that will work in this application and that are available.

 

[harshness]

Plenty of ARM based SBC's that will work in this application and that are available.

"Will work" and a fully tested building plans are often quite different things.