Scanner Radio for PC using SDR RTL

RTL-SDR:
SDR is a Software defined radio. An SDR RTL is a software defined radio using a DVB-T TV tuner dongle. Previously the software defined radios used to be very expensive. Now that there is a new driver developed which accessed the I/Q data, the DVB-T TV tuner dongle can be used as a software defined radio. An SDR RTL is nothing but a Software defined radio with the RTL2832U chipset. I got my SDR RTL from amazon. It is a $20 cheap dongle. You will be amazed with what you can do with these surprisingly cheap dongles. We can access the whole spectrum of radio communication and play with the settings a bit to do what expensive SDR's like SDR play, Airspy and BladeRF can do. 

Parts:
1) The Dongle itself. I ordered my dongle from amazon. 
It is a NooElec NESDR Mini USB RTL-SDR : RTL-SDR

2) A PC with UBUNTU.
Why Ubuntu? Nothing in specific but it is easy to work on Ubuntu with the drivers compared to windows which involves too many installations. I tried both and i felt Ubuntu was much easier. For people with window OS, a Virtual Box or any other parallel operating system installation tool can be used to install Ubuntu.

Installation:
I own a Lenovo Think-pad Edge with an  Ubuntu 16.04 operating system on it. It is a pretty much old laptop but I'm using it only for the software defined radio which should be fine. We use the Ubuntu terminal to type in all the commands. Find terminal in the dashboard or type win+T. This will open the terminal.

Step 1: Before we start any installations, we need to update the PC.

sudo apt-get update

sudo apt-get upgrade

Step 2: Remember to unplug the RTL-SDR from the PC. Keep it unplugged until the driver is installed. With this remembered, Type in 

sudo apt-get install rtl-sdr

Step 3: Now, plug in the device and test if it is detected. 

rtl_test

If the device is detected, go to the next step. If it doesn't, it might be because the device is already plugged in before installing the driver and it is now being used as a DVB-T tuner. We need to fix this. Type in 

lsusb

There should be a device found with the chip-set number on one of the ports. This means that the device is being detected but being used as a DVB then,

sudo nano /etc/modprobe.d/no-rtl.conf

This will create a new blank file called no-rtl.conf where you can blacklist the usage of the tuner as a DVB. Now, after the blank file is created, type in 

blacklist dvb_usb_rtl28xxu

Now, close and save the file saying ctrl x and Y. Then, type in following command and make sure it is not being used.

rmmod dvb_usb_rtl28xxu

Now, test again if the device is detected and this time it should be detected.

rtl_test 

If detected, continue to the next step.

Step 3: Remove all the packages that were previously installed just in case they were installed earlier because we are going to re install some of these.

sudo apt-get purge --auto-remove gqrx

sudo apt-get purge --auto-remove gqrx-sdr

sudo apt-get purge --auto-remove libgnuradio*

Step 4: Now, we install all the packages and drivers needed for the final setup.

sudo apt-get-respiratory -y ppa:bladerf/bladerf

sudo apt-get-respiratory -y ppa:ettusresearch/uhd

sudo apt-get-respiratory -y ppa:myriadrf/drivers

sudo apt-get-respiratory-y ppa:myriadrf/gnuradio

sudo apt-get-respiratory -y ppa:gqrx/gqrx-sdr

It should all finish without errors. Then proceed with the next step.

Step 5: Now, continue with an update and then install the gqrx.

sudo apt-get update

sudo apt-get install gqrx-sdr

This will install the gqrx package. Now, we need to optimize the performance of the GNU radio on the PC being used. For that, we install libvolk1-bin package. This is a package is a vector optimized library which help an application work in the specific instruction set of the specific processor. They help boost the performance.

sudo apt-get install libvolk1-bin

volk_profile

Now that all the installations are done, we can open gqrx by typing gqrx in the terminal or we can also find it on the Ubuntu dashboard.

Usage:
As already discussed, this is a very powerful dongle. Look into the legality of using this in your specific nationality. Now that we are using it responsibly, we can watch the spectrum at all different frequencies and select the specific frequency to listen to it. We have to playing with the type of filter, the bandwidths and the squelch levels to have a good reception. Remember to have this dongle in open air to have a better reception. 

The range of the reception is 52 - 2200 Mhz. You can here several radio stations, police radios, weather channels etc. 

References: 

https://www.rtl-sdr.com/
http://gqrx.dk/