
Current Version 4.2a

A simple FM receiver

The FM receiver will operate in conjunction with rtl2832u based DAB sticks.

Control for the dongles is based on osmocom software (see
their site for details). 
the gui and control is based on the jsdr-fm receiver.

Software is tested with dongles with the fc0012, fc0013 and rt820 tuner.
The e4000 tuner is included but NOT TESTED. Simply because
I have no opportunity to test.

Operation of the FM receiver is quite straight forward. It supports
as input devices:
a. no rig, the software will process whatever is coming in on the input selected sound card 
b. file input, the software will process the contents of a previously
recorded data file
c. the "dongle", the software will process the data coming in from the
dongle - decimated though - and will give control on settings of the dongle.

On start-up  various switches, sliders and buttons will be set according to
a suitable default which can be ovverruled by settings in an ".ini" file.
The default ".ini" file is $(HOME)/.jsdr-fm.ini. Its structure is
quite simple <key = value>, where the key is the internal name of the
switch, slider or button.

Starting the program

When an output device is selected, in relevant cases an input device is selected
and a "rig" is selected pressing the start button will actually start the program.

Two spectrum displays show resp. the incoming data unprocessed and demodulated.
The two average buttons average the spectral values, one for the HF spectrum,
the other one for the LF spectrum.

Selecting a frequency is easy: just key in the frequency in KHz.
The "f--" and "f++" buttons cause the frequency to step to a next
value.
The "cf--" and "cf++" buttons start a timer changing the frequency
on a timer base. Pressing the buttons again change the time, as shown
in the middle. 

The range of frequencies for the RTL2832U based dab sticks is app 64MHz to
app 1700 MHz, depending on the tuner in the stick. Currently, there is support
for the FC0012 and FC0013 as well as for the E4000 tuners. Support for the 2580 tuner is in preparation.

Note that since these sticks have 8 bit samples as output, resolution is
insufficient to decode rds.

A variety of options and switches is available when decoding FM, decoders
may be selected, rds decoders may be selected, a selection may be made
of what data is showed on the display. Of particular interest is the "log"
option, that allows some log data to be written out into a file.

A second interesting option is selecting a bandfilter on the incoming data.
The filterwidth as well as the filterstrength (it is a FIR filter) can be
set.


Note that the permissions are needed to write to the usb gate!!!

look at "what is needed" (and run it on Ubuntu) when you want to
ensure the availability of the various libs that are needed.

When all libraries are available, just run qmake and make


have fun,

jan

