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).

I presented an updated version of my talk at EMF Camp 2022, but mostly covered the hardware reverse-engineering side of things. Sadly EMF's camera broke (or something) and my talk was one of several which weren't recorded.

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
    • Shows the Datatrak software running on a PC at Datatrak HQ, as part of a segment on car theft and “cut-and-shut” crime.
Find me on Mastodon
  • Last modified: 2022/11/23 17:44
  • by philpem