# What is this signal I've recorded?

I've recorded what I believe packet radio signal. I tried few decoding tools on windows to no avail. Can anyone please have a look at this youtube video and tell me how to decode this signal or what it is?

That is POCSAG (Post Office Code Standardization Advisory Group). Typically used by numeric and text pagers.

Wikipedia also has a sample of the audio that you can compare against.

Some have used rtl_fm combined with multimon-ng to decode POCSAG. A snippet from this site shows:

rtl_fm -N -o 4 -A lut -s 22050 -C -f 148.397M - | multimon-ng -t raw -a POCSAG512 -a POCSAG1200 -a POCSAG2400 -f alpha /dev/stdin

• Many thanks, I'll have a go with multimon-ng! Jul 30 '14 at 0:51
• Are you sure? I'm not familiar with the protocol nor have I tried to verify with a decoder, but the sync tones at the start of each transmission do not sound the same. Jul 30 '14 at 20:54

PDW in windows will do just fine... no need to grab a linux box (unless you have one setup). Certainly much easier than some rtl_fm/multimon setup.

http://www.discriminator.nl/pdw/index-en.html

• Thanks very much for suggesting pdw, will give it a go (; Sep 1 '14 at 4:33