(This guide is based on this page from rtlsdr.org. If there are any ambiguities, please check the original source)
Before we continue, we'll have to install the Windows driver for the RTL USB stick and then swap it for a 'low level access' driver. The default driver assumes you'll just be using the RTL-SDR for watching TV or radio but we want to be able to control it to do much more.
Steps to install
- Follow the instructions here.
- Note you will need to download a ZIP file from Airspy. Find the downloads button on the top menu. Next to the 'SDR Software Package' heading click on the download button to download sdrsharp-x86.zip.
- Extract the file and use the install.bat to install SDR# and RTL-SDR.
- After plugging in the USB tuner, open '
zadig
' to configure the USB tuner. Make sure that the 'List all devices' option is enabled under the Options tab.
Now, to get the command line utilities you can get the 'pre-built' windows RTL-SDR files
- Get prebuilt binaries: here.
- Extract the files and open it in the command line (Start > Run > CMD).
The files inside the x32/x64 directories are as follows:
Testing the RTL-SDR Device
- Test the tuner with the following command:
rtl_test -t
Capturing Data (Standalone)
- Capture some samples (to a file):
rtl_sdr -s 2e6 -f 110.9e6 -n 2e6 dump.bin
- Selected examples will capture 2 million samples (-n = number), at a sample rate of 2 megasamples/second (-s) and with a center frequency of 110.9 MHz (-f). Samples will be captured into
dump.bin
Capturing and Displaying Data
Before capturing data for your assignment, it is a good idea to have some real-time information about the signal. This is where the tool SDRSharp comes in (which you installed when getting the driver above) - it can show the spectrum in two ways - a spectral density as well as a waterfall map.
In SDRSharp there are two main ways to connect to your tuner stick, via a 'Spectrum Server' (aka RTL-SDR TCP), or directly - RTL-SDR USB. If you want to use the spectrum server, in the command line run
rtl_tcp
, and then connect to the spectrum server in SDRSharp. Otherwise just use the USB version.Next to listen / decode data use the 'Play' button in the top left hand corner of the screen. The spectrum and water-fall plot will begin changing. If all of the spectrum is flat, you might need to increase the gain of the device (otherwise you are just receiving noise!).
FM radio is known as 'wide band FM', other forms of frequency modulation may be for walkie-talkies etc, which will be 'narrow band FM'.
After you have identified a signal in SDRSharp, you can then 'stop' SDRSharp and record this using
rtl_sdr
- as shown in the previous section. Substitute the appropriate centre frequency and sampling rate (which depends on the bandwidth). The RTL-SDR device will adjust its filter bandwidth relative to the sampling rate (to some degree).References
- rtlsdr.org/softwarewindows.
Troubleshooting
![Download Download](/uploads/1/2/5/7/125734955/672463287.jpg)
- If you are using Windows 7/8 and having issues, check out more information here
- For Windows 7 the Zadig software (which installs the USB Driver - WinUSB) needs to be run as 'Administrator'.
- For Windows 8 it seems running it as Non-Administrator works better (try both if one fails!)
- If the device seems to fail, it often helps to get Windows to not 'auto-load' the driver for this device. If hard to do, then in ZADIG do a 'show all devices'.
- If you are getting no signals in SDRSharp (also known as you only see noise no mater what frequency you tune in to), adjust the gain (even use auto gain - AGC - automatic gain control).
- If you are getting bad signals, you may need to adjust the antenna. It is good to put the magnet of that antenna on a large metal object, and generally closer to a window/outside will give you better signals. (Some parts of the lab in 50-S202 and 78-212 have very poor signal quality).
- If one of the
rtl_*
programs needs to be stopped you can stop it withCtrl-C
- Getting an error message like 'usb_open error -3, Fix the device permissions' usually means that you already have one program using RTL-SDR. You need to close the other program (or at least 'stop' it if it is something like SDRSharp).
- Some anti-virus software doesn't like the idea of having alternative drivers for USB devices. So check that your anti-virus isn't deleting any files such as libusb-1.0.dll
- If your virus scanner is breaking zadig, you can get it directly from the source: here
- Windows Powershell says it cannot load the file in current directory. Use .rtl_sdr etc