RTLSDR Scanner FAQ

1 Installation

1.1 How do I install RTLSDR Scanner?

1.2 Import error: Error loading librtlsdr. Make sure librtlsdr (and all of its dependencies) are in your path

1.3 Import error: matplotlib requires pyparsing

1.4 Other ImportError: No module named ...

 

2 Terminology

2.1 Scan vs Sweep

2.2 Decibels per root Hertz

2.3 Occupied Bandwidth

 

3 Usage

3.1 Pan and zoom

3.2 Selecting a range

3.3 Hangs and pauses

3.4 Command line GPS

 

 


 

1 Installation

 

1.1 How do I install RTLSDR Scanner?

The easiest way is to install on Windows using the installer, otherwise look at the installation page.

1.2 Import error: Error loading librtlsdr. Make sure librtlsdr (and all of its dependencies) are in your path

The rtlsdr driver is either not installed of the software cannot find it in your PATH, check the driver installation page for more information.

1.3 Import error: matplotlib requires pyparsing

Under Windows you may need the Microsoft Visual C++ 2010 Service Pack 1 (probably the 32 bit version) for pyparsing to work.

Alternatively you can try download easy_install and from the command prompt run:

cd \Python27\Scripts
easy_install pyparsing

1.4 Other ImportError: No module named ...

The software is missing one of it's dependencies.
For Windows run the installer again and select the appropriate library.

For Ubuntu run sudo apt-get install python-wxgtk2.8 python-matplotlib python-numpy python-imaging pyserial
For Fedora run sudo yum install python-matplotlib-wx python-pillow pyserial
For OSX run sudo port install <name> where name is the module (check on the installation page)

If you still get errors check the installation page which is updated as necessary.

 


 

2 Terminology

 

2.1 Scan vs Sweep

A scan consists of one or more sweeps of a frequency range.

2.2 Decibels per root Hertz

The scanner analyses signal data using power spectral estimation which produces data with these units.  The data is scaled to the frequency so in this case it can be interchanged with Decibels.

2.3 Occupied Bandwidth

The bandwidth that contains 99% of the total power.

 


 

3 Usage

 

3.1 Pan and zoom

Drag the plot to pan and use the mouse wheel to zoom.

3.2 Selecting a range

Use the middle mouse button to drag a selection

3.3 Hangs and pauses

If the software becomes unresponsive try changing the display to 'Status' before a scan as plotting the spectrum is very time consuming.
Reducing the frequency range and the number of sweeps will also keep the speed up.

If you have Visvis installed (the Windows installer has an option for this), you can change the display type to 'Preview' for faster but less detailed rendering.

3.4 Command line GPS

GPS can be used from the command line by using the '-c' switch to point to a configuration file, e.g.:

rtlsdr_scan.py -s 88 -e 108 -c path/to/config.conf scan.rfs

An example configuration file can be found here.

Comments

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Hi, I been using your (excellent) Software for spectrum measurements, is there a way to estimate the total time of a scan from the dwell time and total bandwidth?
Thanks for your time!

Al's picture

Hi Guillermo,
I'll add a measurement time estimation when I get chance. Good idea, thanks.

Hi. Thank you for creating your excellent software. I'd like to ask if you could provide a "periodic image save" function which will capture the plot or spectrogram at regular, user defined intervals, and with the option of JPG as well? Or is there a command-line solution for doing this?

Thanks again,

Al's picture

Hi. I like the idea and I'll add it as soon as I get a chance.

Hi!
Thank you for this fantastic software.
I was using it, but accidentally removed usb dongle during a scan.
Now, sw don't work any more, i've tried to reinstall but i have the same problem.
The dos box appears, i can read:
Rtlsdr scanner
found rafael micro R820T tuner
Then a lot of errors but it close the window so fast i can't read.
Can you help me? Is it a known problem?
Sorry for my bad english
Thank you
Max

Al's picture

Thanks max, glad you like it. Your problem sounds like it's the dongle.

Try opening a 'Command Prompt' and typing:

rtl_test

You should get something similar to:

Found 1 device(s):
  0:  Realtek, RTL2838UHIDIR, SN: 00000013

Using device 0: Generic RTL2832U OEM
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 4
0.2 42.1 43.4 43.9 44.5 48.0 49.6
Sampling at 2048000 S/s.

Info: This tool will continuously read from the device, and report if
samples get lost. If you observe no further output, everything is fine.

Reading samples in async mode...

If not there could be a problem with the dongle.  One of my dongles didn't always start up properly when I plugged it in, I could get around this by unplugging it for a few seconds then plugging it back in (it could take several tries), or using a different USB port.

My problem turned out to be a dodgy decoupling capacitor in the dongle, I placed 1µF capacitor across pins 1 & 4 of the USB connector to fix it.

Thank you for your fast answer.
My dongles and usb port are ok, i've tested.
By the way, rtlsdr scanner should start even without any dongle, right? (it was so before the problem)
I've saved a part of error message with prtscr key but i'm not able to copy here.
By the way, after 'found etc' i read:
Traceback :
File "c:\programs etc etc \rtlsdr_scan.py", line 116, in
frame = framemain<"RTLSDR scanner", pool>
And so on for a lot of lines.
As told, i've uninstalled and reinstalled all, but no solution.
It seems something is not correctly deleted-rewritten or the problem is in some part modified once
by the installer (p.e. registry key?)
I've installed all on another pc and it works fine, but i need it on the first pc, and i would like to avoid
complete format and reinstall of S.O.!!
Can you help?
Thank you very much.
Max

Hi!
I've uninstalled, deleted all files and directories related to 'python' and 'rtlsdr' (not deleted by the uninstall),
manually deleted all keys from registry ('python' and 'rtlsdr')
and reinstalled.
Now it works fine, but if i try to use any of the menu 'edit' (p.e. radio devices)
a windows error appears, that kind with send or not send boxes,
and close all.
In the 'technical info' box i can see 'python.exe error'.
So, any idea about this problem?
Thank you very much,
Max

Al's picture

Hi Max,

I haven't been able to track down the problem with the registry but if it happens again could you post the full error message here if you get chance?

Thanks for the information about both device windows, I'm aware of it and trying to track it down at the moment.

Hi.
I've completely reinstalled my o.s. to be sure to delete all.
I've downloaded installer, and run it.
It stops after a while with message: "can't find pyton, aborting..."
It seems the installer looks fot pyton before installing it.
So i've installed pyton manually. and restarted installer.
It works, upgrades pyton at newer version, till the end.
After restarting pc, i start rtlsdr, all ok, but when i click on radio devices i obtain the usual windows error
'error in pyton.exe, will close'
Remember, on the same pc the first time it worked fine, till i accidentally removed the dongle, so it's
not a problem of hw or o.s. configuration on my pc,
From the first installation to now the installer version has changed.
Is it possible to have the last week version?
Thank you very much
Max

Al's picture

Thanks for the information about the installer, I'll try and get that fixed soon.

Have you tried 'Edit -> Reset settings' from the main menu? Removing the dongle may have left the configuration in a mess.

Hi all,
I have a problem, I use RTL2832U USB on Win7.
When push Start, Status bar appear Error code -12 when opening SDRInfo : ice index= -1.
And on Dos screen : Found Rafael Micro R820T tuner usb_open error -12.
Can you help me ?

Did you use zadig? Sure to have installed correct driver (winusb)?

Al's picture

It does sound like a driver installation problem, Windows is probably trying to use it as a TV tuner so the rtlsdr driver can't access it. Try the installation instructions here

Thank you.
The problem was solved, but I also do not understand why.
I add one other receive radio equipment (localhost: 1234) but did not select it and the error disappeared !!!!
Can you explain?

Al's picture

Sounds like a bug to me, I'll try and track it down.

Al's picture

I've just uploaded a fix which should stop this error (fingers crossed!)

How do I increase the sample rate, by default it uses 2MS/s but from my testing, I can use the device stably up to 2.8MS/s

Al's picture

The sample rate is currently fixed, I did try adding an option to change it a while ago but I ran into too many problems and removed it.

At some point I hope to reinstate it.

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