Connect your VLF signal and start recording

Now connect your VLF signal into another one of your soundcard inputs. The "UltraMSK.sh" can be used to start up the receiver software. One msk process is started for each VLF station that you wish to record. In the script below, three receiver processes are started to record VLF stations NLK, NWC & NPM.

[james@swan UltraMSK-1.0.2-F17]$ more UltraMSK.sh
#!/bin/bash

#sound card & input channel numbers
#edit these to suit
CARD=M1010LT
PPS=8
VLF=3


#kill the JACK server if it running
killall jackd
sleep 1

#and then start it
#Fedora 17: jackd needs X server
#use Xvfb to create one
if [ -z "$DISPLAY" ]; then
echo "No DISPLAY. Creating virtual X Display"
Xvfb :1 &
export DISPLAY=:1
fi
jackd -R -d alsa -d hw:$CARD -n 20 -p 256 -r 96000 &> jack.log &

#kill any msk processes
killall msk
sleep 2

#and then start them
./msk -f 19800 -l -c NWC -s $VLF -p $PPS -d -m > pps.dat &
./msk -f 21400 -l -c NPM -s $VLF -p $PPS &
./msk -f 24800 -l -c NLK -s $VLF -p $PPS &
[james@swan UltraMSK-1.0.2-F17]$

Note that you may need to install Xvfb. Run "yum install xorg-x11-server-Xvfb" as root.

Back 18 Aug 2012