SoDiRa

Software radio

Version 0.084


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last changes

  • CELT codec implemented
  • Bug fix DRM AM FM switch
  • Bug fix text messages DRM+
  • 384 kHz samplerate added

  • soundfiles

    (saving via right mousebutton, with SoDiRa via "play" button starts playing )

    France Bleu 864 kHz AM Stereo demonstration, AM signal close right
    Radio Klassik VHF FM stereo with RDS, 192k samplerate
    Radio Vatican 7190 kHz DRM with high SNR > 35 dB
    Spark DRM+ demonstration generated with Spark and 1000 Hz frequency offset
    AM Signal 17700 kHz IQ balancing demonstration, (button "IQBal")
    RTL Radio 6095 kHz noise blanker demonstration, (button "iNB")
    DCF77/HBG Signal DCF77 Decoder demonstration

    characteristics:

  • Software Defined Radio (SDR) for analogue and digital modulation types
  • modulation types: AM envelope, AM synchronous, AM stereo, AM synchronous upper/lower band, LSB, USB, FM, VHF FM mono/stereo, DRM30, DRM+
  • decoding of AMSS, DCF77, RDS
  • minimal requirements:

  • 1 soundcard fullduplex, stereo, 48 kHz or 96 kHz samplerate
  • at least Pentium 1000 MHz
  • 32 Bit Windows OS (Windows 98/2000/XP/Vista)
  • additional requirements for 192 kHz samplerate:

  • 1 soundcard fullduplex, stereo, 192 kHz samplerate
  • Windows XP SP1 or Windows Vista
  • supported receiver:

    model name tuning range audiobandwith oscillator chip communication device distributor/developer
    Elektor DRM receiver 03/2004 500 kHz - 20 MHz 12 kHz AD9835 DDS COM-Port,
    FTDI-USB seriell adapter
    Geist Electronic
    Burkhard Kainka
    DRT1 30 kHz - 30 MHz 12 kHz AD9951 DDS COM-Port,
    FTDI-USB seriell adapter
    SAT Schneider
    DiRaBox DRB30 30 kHz - 30 MHz 15 kHz AD9951 DDS DRB30/32 USB-LPT adapter NTI
    DiRaBox DRB32 30 kHz - 30 MHz 15 kHz AD9951 DDS DRB30/32 USB-LPT adapter NTI
    Elektor USB receiver 05/2007 30 kHz - 30 MHz 20 - 200 kHz IQ Cypress CY27EE16 FTDI-USB intern Burkhard Kainka
    HCJB Pappradio 30 kHz - 30 MHz 20 - 200 kHz IQ ICS307-03 COM-Port,
    FTDI-USB seriell adapter
    Pappradio Homepage

    supported communication devices:

  • COM-Port
  • FTDI-USB seriell Adapter via Bit-Bang mode (fast mode)
  • DRB30/32 USB-LPT adapter
  • Elektor USB receiver 05/2007 FTDI-USB intern

  • first beginning:

  • download software and driver for FTDI Chip, unzip this in any directory, install FTDI driver
  • plug communication device cable to PC and receiver (COM or FTDI-USB port)
  • plug wave device cable to PC and receiver (line-In or mikrofon-In)
  • select wavedevices and mixerchannels (->config ->wavedevice)
  • select receiver hardware (->config -> receiver), click "connect"
  • select a frequency via mouse or keyboard
  • select a demodulation or decoding mode at the main window right below

  • operating:

    mouse click spectrum above:

    The new frequency is the pointed frequency aligned to 1 kHz grid.

    mouse click spectrum below:

    The new frequency is the pointed frequency not aligned.

    mouse wheel spectrum above:

    The frequency is increased/decreased by 1 kHz.

    mouse wheel spectrum below:

    The frequency is increased/decreased by 100 Hz.

    arrow left/right

    The tuningstep is increased/decreased to the next intern defined step. (1 Hz, 10 Hz, 100 Hz, 1, kHz, 2.5 kHz, 5 kHz, 6.66 kHz, 9 kHz, 10 kHz, 25 khz, 50 kHz, 100 kHz)

    arrow up/down

    The frequency is increased/decreased by one tuningstep.

    align - button "l"

    The frequency will be aligned to the tuningstep grid.

    direct edit - buttons:"0".."9" "k" "enter" "m" "h" "esc" ","

    With "enter" or with "k" the frequency will be changed with kHz as unit. With "m" the unit is Mhz, with "h" Hz. "esc" will be escape the last edit and the old value will not be overwritten. For the broadcast example Deutsche Welle 6075 kHz: "6" "0" "7" "5" "enter" -or- "6" "," "0" "7" "5" "m"

    main tuning - button: "a"

    The oscillator frequency will be changed directly the IF frequency will be changed indirectly. The input range in the upper window will be changed due to this. If the new frequency is not supported by the oscillator the IF frequency will be also changed by a small offset.

    disadvantages:
  • only slow tuning because data has to be send to the receiver
  • strong glitches will be produced by some receiver
  • intermediate tuning - button: "i"

    The intermediate frequency will be changed directly the oscillator frequency will be changed indirectly.
    Within the inputspectrum you can select a frequency. If you are close to the feft or right border the oscillator frequency will be also changed.

    advantage:
  • fast tuning is available
  • mirror tuning

    Some receiver produce mirror frequencies with this option you can tune very easy to the true frequency, vice versa, if you have the true frequency you can find all mirror frequencies.

    searching

    The receiver search a new frequency. The conditions for the the stop are internaly defined by ca. 20 dB SNR.

    shifting

    For the optimising of the distance to interfering signals. The oscillator and the IF frequency will be changed together to lock the main frequency to the equal frequency. But a potentially interfering signal will be moved to outside of the filterborders.

    oscillator lock - mlock

    If activated the oscillator frequency can not changed anymore. Then the intermediate tuning is available only. Use this if you use the intermediate tuning and you dont want to change the oscillator frequency.

    antenne/input selector

    Some receiver supports multiple inputs. Here you can choose any of this.

    attenuation selector

    Some receiver supports multiple attenuations. Here you can choose any of this.

    receiver options

    Some receiver supports any other options. Here you can choose any of this. See receiver descriptions.

    impulse noise blanker - iNB

    Strong glitches that will be get from oscillator frequency change or from antenna by man made noise by switches will be here suppressed.

    IQ-Balance - IQbal

    IQ receiver must have for the I- and Q- channel (inphase , quadraturephase) the exactly same phase and amplitude behavior for the whole inputspectrum and the whole path from IQ-mixer to the AD-converter. Otherwise some pseudo frequency will be displayed and heareable.
    Here a algorithm correct this behavior.

    DC offset filter - DCfilt

    A potentially missing DC filter can produce a stable spectraline at the upper window. This will influence the behavior of searching and demodulation.
    With this option you can filt out the DC by software.


    known problems, questios and answers:

    DRM is not operating with 192 khz samplerate

  • with version 0.072 this problem is solved
  • that is the DRM decoding performance?

  • since version 0.060 close to DREAM, practically the performance is the same
  • The DRM signal is good but the decoder is not working

  • DRM mode C und mode D are not supported at this tiome
  • sometimes synchronisation is wrong, use "reset" button
  • the audiocodec is not supported
  • How can i receive the VHF FM? The receiver range is only up to 30 MHz.

  • you need a second receiver with 10.7 MHz IF output signal and a soundcard with 192 kHz samplingrate
  • plug this signal to your receiver, select 10.7 MHz with SoDiRa
  • choose FM mode
  • Is the DCF77 time ecactly?

  • about 50 - 200 ms is the differences
  • The DCF77 time is not taking over after "synchronise systemtime"

  • The program has to started with admin permission