Using tx3. send wspr signals using #!/bin/sh while true do for j in `seq -100 1 100` do for i in $* do cat data_ve4feb_raw | awk -v freq=$i -v offset=$j -v port=ttyUSB0 -f ./wspr_tx3 > /tmp/wspr m=`date '+%M'` s=`date '+%S'` a=2 tx_time=`expr $m % $a` while test $s -ne 0 -o $tx_time -ne 0 do m=`date '+%M'` s=`date '+%S'` a=2 tx_time=`expr $m % $a` done sleep 1 date sh /tmp/wspr date done done done