datatrak:start

Datatrak reverse-engineering

Datatrak was a land-based radio navigation system which used the phase difference between several long-wave radio signals to pinpoint the location of a receiver.

I acquired a few of Datatrak location-only “Trakbak” receivers from eBay, and have been slowly reverse-engineering them.

I'm currently trying to build a desktop Datatrak LF signal simulator, and reverse-engineer the receiver to the point where they could be used to receive signals in the 136kHz (2200 metre) UK LF amateur radio band.

You may also find the presentation I gave at CampGND 2020 interesting: (slides) (recording).

UPDATE: I'll be presenting an updated version of my talk at EMF Camp in June. This time around I'll be concentrating more on the reverse-engineering project. It's worth watching the CampGNDd talk first, or at least skimming through the slides.

NEW - April 2022

Datatrak was featured on TV several times during its development.

Thanks to Alasdair for finding these and sending the links. Both videos are on Youtube.

  • BBC Tomorrow's World, 28 May 1987 – featuring either a prototype or Mk.1 Locator being demonstrated in the London area, using the initial three transmitters.
    • Shows early demonstration software and either a prototype or Mk.1 Locator receiver.
  • Top Gear, 1990 season, 5th episode – Jeremy Clarkson tries to steal a Vauxhall Cavalier (!) which was fitted with Datatrak.
    • This episode also features the Autotag immobiliser, which allows the car to be remotely disabled using a radio paging signal.
    • Shows what is believed to be the later 'base station' software used by the Datatrak call centre at the time
  • Last modified: 2022/05/17 02:06
  • by philpem