Changed -g 50 to -g $GAIN

receive_iss.sh

@@ -1,3 +1,3 @@
 #!/bin/sh
 datetime=$(date +"%Y%m%d-%H%M%S")
-timeout 660 /usr/local/bin/rtl_fm -M fm -f 145.8M -s 48k -g 50 -p 55 -E wav -E deemp -F 9 - | /usr/bin/sox -t raw -e signed -c 1 -b 16 -r 48000 - /usr/share/html/iss/iss-$datetime.wav rate 11025
+timeout 660 /usr/local/bin/rtl_fm -M fm -f 145.8M -s 48k -g $GAIN -p 55 -E wav -E deemp -F 9 - | /usr/bin/sox -t raw -e signed -c 1 -b 16 -r 48000 - /usr/share/html/iss/iss-$datetime.wav rate 11025