Notes
on Using The RTL2832U + E4000 USB DVB TV Dongle
as a V/UHF SDR
Richard Cooper G4WFR
Having
seen mention on the Internet about the possibility of using a low cost
USB TV dongle as an SDR (Software Defined Radio), I decided to find out
more as at the costs mentioned, there really wasn't much to lose if it
didn't work.
With SDR software, a frequency range of 64 MHz to 1700 MHz is possible
& AM, FM (narrowband & wideband), LSB/USB & CW
modes are supported.
The
USB TV dongle is the type designed
for digital television reception & it contains the Realtek
RTL2832U chipset & the tuner part is an Elonics E4000. A quick
search on eBay using the search criteria RTL2832U E4000 produced
several hits. Some units are available for around £12.
I chose a 'Newsky DVB-T Stick' sourced on eBay from seller cosycave,
although there are many others available. This dongle is supplied with
a short antenna adapter cable to convert the miniature socket to a
standard Belling Lee style TV socket.
I
use Windows 7 O/S although there appears to be lots of software for
Linux systems. For Windows users, a special driver is required, this
file is called zadig.exe. This driver is available at http://rtlsdr.org/softwarewindows
although version 2.0.1.154 is available here.
Plug the USB dongle into your USB port. Run the zadig.exe program,
select 'Options' - 'List All Devices'
Now, in the drop down box of the main Zadig window select RTL2832U
& the driver file below this should show WinUSB (vx.x.xxxx.xxxxx) Click
on install or replace driver (ie the big button below the driver file
details)
Once the driver is installed, you need the SDR software. SDR# (called SDR Sharp) works perfectly well & is the software I use with success. SDR# is available from http://www.sdrsharp.com/index.php/downloads. Select the SDR# Dev version as this works with the RTL2832U dongle. The file name is sdr-nightly.zip, just download this and unzip to either a folder on your desktop or a folder in your C: drive. There is no installation routine, just click on the SDRsharp.exe file, you may now need to confirm you wish to run the program, click 'Run' if you are asked and the SDR# software should launch.
You
are nearly there!
There should be 2 large windows with black backgrounds, the top will be
the spectrum display, the lower will be the waterfall display.
On the left are various settings. First, nest to 'Front end' is a pull
down box, select 'RTL-SDR / RTL2832U', Press the 'Play' button near the
top left & you should see the spectrum & waterfall
displays. Select your mode (a good test is to select WFM) and enter a
frequency in the 'Centre' box. The frequency is entered in Hz so a
frequency of 105.200 MHz is entered as 105,000,000 (press enter) and
this will be the centre frequency of the spectrum display. The spectrum
display will show this frequency & the range +/- 1 MHz. This
would allow you to view for example, the whole of the 2m amateur band.
When listening to narrow FM signals (used for normal radio
communications) I found that reducing the filter bandwidth from 12500
to 9500 improved signal to noise ratio without affecting the quality
too much.
Tuning can be carried out by clicking & holding mouse then
dragging horizontally. If you see a signal on the spectrum or waterfall
display, just click on it to immediately tune to the signal. Have a
play, you can't break it!
One
important
entry is the 'frequency correction'. I found that I had to use this as
there were frequency errors which increased
as you tuned higher in
frequency. To get to this, when the software is running, click on the
‘Front
End’ box and you will see where you can enter the frequency
correction (ppm). For my dongle, I had to
set it to 105 but each dongle
may differ.
Below are the receive sensitivity test results, measuered
on narrow FM (NFM) with the 12.5 KHz filter (set to 12500) selected.
| Frequency | Sensitivity (NFM) |
| 70.4000 MHz | -112dBm |
| 101.1000 MHz | -116dBm |
| 121.1000 MHz | -119dBm |
| 145.2000 MHz | -114dBm |
| 168.5000 MHz | -114dBm |
| 432.2000 MHz | -119dBm |
| 458.0000 MHz | -115dBm |
| 1050.0000 MHz | -116dBm |
For further information, please try these sites:
SDR#
reddit
RTLSDR
SDR#
Yahoo Group
I
hope you all enjoy experimenting with very low cost VHF/UHF SDR. Have
fun......
Richard
G4WFR.