Pager network snifffing

Kenneth tapping a pager’s output to sniff pager traffic. He bought an old pager and was happily surprised that he could easily tap into the demodulated digital signal.

A little poking around between the circuit boards and Google and I found that this pager uses the Toshiba TA31142 FM detector specifically designed for pagers.  What luck that the datasheet was even kind enough to indicate which pin the finally demodulated FSK data was outputted on (the red emphasis in the figure above is my own).  This means that with some tricky soldering, I can take advantage of the fact that Motorola put all this effort into building a good FSK quadrature detector, and I can spend my time in the much more interesting and pleasant digital electronics land.

Adafruit has also demoed this before.

Leave a comment

Your email address will not be published. Required fields are marked *

Notify me of followup comments via e-mail. You can also subscribe without commenting.