9 December 2012

Feeding baudline with the KX3's I/Q Output

After someone mentioned in ##rtlsdr that it was possible to pipe I/Q data into baudline via stdin, I wondered if I could do the same with I/Q data from the KX3.  As I'm already feeding the I/Q data from the KX3 into gr-kx3 using pulseaudio, I needed to use pulseaudio as the source for baudline but it isn't supported, so I used parec to pipe the I/Q signals into baudline.

# blkx3 - a bash script to feed I/Q data from a pulse audio device into baudline

parec --format=s16le --channels=2 --rate=$SAMPLE_RATE --latency-msec=5 | \
$BL_BIN -scrollcontrol -record -stdin -channels 2 -quadrature -samplerate \
$SAMPLE_RATE -basefrequency $1

You may need to change the path to baudline in the script and maybe also the sample rates. The script takes the baseband centre frequency as its only parameter.

$ blkx3.sh 7184500


Dirk said...

Are you feeding fldigi with the audio or the i/q input from your KX3?

g0hww said...

Hi Dirk,
I'm using PulseAudio devices for both the I/Q and audio out of the KX3. I can feed both signals into multiple software programs. I'm feeding fldigi from the SignalinkUSB that I use as a soundcard for digimodes. The I/Q output is fed into a Griffin iMic soundcard (not so great) via a stereo line isolator.