====================== Cloning the repository

• Clone as usual
• Checkout the f4exb branch: git checkout f4exb

============== Funcube Dongle

Funcube Dongle Pro+ support will need "libasound2-dev" installed. ("libhid" is built from source). Install the rules file "fcdpp.rules" in "/etc/udev/rules.d" to gain the "root access" needed to control the dongle.

Funcube Dongle Pro+ USB drivers are broken on some hardware with recent kernels. It works well for me with an Atom Chipset, which has Full Speed USB ports, or a "Valleyview" Chromebook (kernel 3.10). A Desktop with the "same" chipset needs kernel 3.2, available with Debian 7 "wheezy". YMMV.

========== For Ubuntu

sudo apt-get install libqt5multimedia5-plugins qtmultimedia5-dev qttools5-dev qttools5-dev-tools libqt5opengl5-dev qtbase5-dev libusb-1.0 librtlsdr-dev

mkdir build && cd build && cmake ../ && make

librtlsdr-dev is in the universe repo. (utopic 14.10 amd64.)

Use cmake ../ -DV4L-RTL=ON to build the Linux kernel driver for RTL-SDR (Experimental). Needs a recent kernel and libv4l2. Will need extra work to support SDRPlay. Needs cp KERNEL_SOURCE/include/linux/compiler.h /usr/include/linux/ and cp KERNEL_SOURCE/include/uapi/linux/videodev2.h /usr/include/uapi/linux/ and package libv4l-dev.

The Gnuradio plugin source needs extra packages, including liblog4cpp-dev libboost-system-dev gnuradio-dev libosmosdr-dev

For non standard installations of RTL-SDR library, the GNU Radio runtime and gr.osmocom drivers use the following variables in the cmake command line. The paths specified are just examples:

• For GNU Radio runtime:
  • Includes: -DGNURADIO_RUNTIME_INCLUDE_DIRS=/opt/install/gnuradio-3.7.5.1/include
  • Library: -DGNURADIO_RUNTIME_LIBRARIES=/opt/install/gnuradio-3.7.5.1/lib/libgnuradio-runtime.so
• For gr.osmocom:
  • Includes: -DGNURADIO_OSMOSDR_INCLUDE_DIRS=/opt/install/gr-osmosdr/include
  • Library: -DGNURADIO_OSMOSDR_LIBRARIES=/opt/install/gr-osmosdr/lib/libgnuradio-osmosdr.so
• For RTL-SDR library:
  • Includes: -DLIBRTLSDR_INCLUDE_DIR=/opt/install/rtlsdr/include
  • Library: -DLIBRTLSDR_LIBRARIES=/opt/install/rtlsdr/lib/librtlsdr.so

There is no installation procedure the executable is at the root of the build directory

============ For Debian 8

Debian 7 "wheezy" uses Qt4. Qt5 is available from the "wheezy-backports" repo, but this will remove Qt4. Debian 8 "jessie" uses Qt5.

sudo apt-get install cmake g++ pkg-config libfftw3-dev libusb-1.0-0-dev libusb-dev qt5-default qtbase5-dev qtchooser libqt5multimedia5-plugins qtmultimedia5-dev qttools5-dev qttools5-dev-tools libqt5opengl5-dev qtbase5-dev librtlsdr-dev

mkdir build && cd build && cmake ../ && make

The same remarks as for Ubuntu apply...

============ Known Issues

• Actually NFM seems to be working pretty well
• Does not work properly for RTL-SDR sampling rates not multiple of AF sampling rate (48000 Hz). This is because the interpolator/decimator is not a rational resampler actually (just does one or the other). For now please use 288, 1152 or 1536 kHz sampling rates,
• RTL frontend will have bad aliasing in noisy environments. Considering the size of the hardware there is no place for proper filters. With good filtering and a good antenna up front these devices work remarkably well for the price!
• Aliasing can be annoying for broadcast FM. In this case try to shift the signal until you find a clear background for your station. This is a limitation of the RTL hardware so just use this workaround.

=================== Done since the fork

• Added ppm correction for the LO of RTL-SDR. This uses the corresponding function in the librtlsdr interface (range -99..99 ppm)
• Added a preset update button (the diskette with the yellow corner) to be able to save the current settings on an existing preset
• Added variable decimation in log2 increments from 2^0=1 to 2^4=16 allowing to see the full 2048 kHz of spectrum if so you wish
• Better handling of rtlsdr GUI display when settings change (initial load, load of presets)
• Added display and precise control of the shift frequency from center frequency of the NFM receivers.
• Removed useless spectrum visualizer in NFM receivers. Created a null sink class to fit corresponding parameter in NFMDemod class constructor.
• Added display and precise control of the shift frequency from center frequency of the SSB receivers.
• Make the sidebands appear correctly on SSB channel overlay. Limit to +/- 6 kHz to fit channel spectrum analyzer window
• SSB bandwidth can now be tuned in steps of 100 Hz
• NFM and SSB receiver in focus trigger the display of the central frequency line on the spectrum frequency scale thus facilitating its identification
• Added AM demod so now you can listen to air traffic!
• Added the possibility to change the brightness and/or color of the grid.
• Make the low cutoff frequency of the SSB filter variable so it can be used for CW also.
• NFM demodulation without using atan and smooth squelch with AGC suppressing most clicks on low level signals and hiss on carrier tails. Only useful modulation comes through.
• Added working WFM demodulation.

===== To Do

• Missing de-accentuation on WFM
• Optimize (no atan2) and enhance (stereo, RDS?) WFM.
• Make the the SSB filter frequency bounds tunable so that it can be used for CW. Change marker overlay accordingly.
• Possibility to completely undock the receiver in a separate window. Useful when there are many receivers
• Larger decimation capability for narrowband and very narrowband work (32, 64, ...)
• Even more demods ...
• Triggering capability like on expensive spectrum analyzers to trap burst signals
• recording capability