Friday 31 August 2012

Cheap receiver for 23 cms DVB-T



I recently bought a Newsky DVB-T Dongle with a 
RTL2832U / E4000 chipset. This is the type of Dongle 
being used by Amateurs and others as a wideband SDR.
Using the provided BlazeHDTV 6.0 Windows software it 
was possible to receive DVB-T transmissions sent by 
my USRP2 code on 1.3 GHz, see above screenshot.
The reason I look a bit green at the edges in the picture
is because I was Chroma Keyed onto a backdrop of my
antennas. I am staring into space because I was looking
at a monitor in the shack. The picture is a full screen grab
of the live transmission.

For interest the parameters were DVB-T, 7 MHz Channel,
2K mode, QPSK modulation, 3/4 FEC, 1/16 guard with a
video rate of 5.8 Mbits/s, frequency 1.3 GHz and power
about 2 watts. These parameters were an arbitrary choice.

I had to use Windows to display the received pictures
because I could not get Linux to create the /dev/dvb 
device for the Dongle. A quick Google search showed 
that I am not the only person having this problem. 

The SDR software works perfectly on Linux.

4 comments:

  1. How did you get the stick to tune 1.3GHz - or were you using a converter?

    ReplyDelete
  2. I just told the BlazeHDTV software
    to scan 1300000 - 1320000 KHz and
    it locked onto my signal. The DVB-T
    Tuner uses the RTL2832U / E4000 chipset
    which is the same chipset being
    used by the osmosdr
    http://sdr.osmocom.org/trac/wiki/rtl-sdr
    people and will tune part of 23 cms.

    ReplyDelete
  3. OK thanks for that - would have thought the software would limit the frequencies you can tune to the tv bands. Good news keep up the work - enjoy reading your missives.

    ReplyDelete
  4. Yes so did I but if you put rubbish data
    in it, it just says enter a frequency between
    10MHz and 2GHz. However it will only scan
    properly the first time after starting the
    program. If you try to scan again it won't
    do it, you then have to restart the program,
    weird!

    The program also works with DVB-S too. Not bad
    for £12 for the DVB-T dongle and Blaze software.

    ReplyDelete