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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.
Contents
- The Datatrak signal – technical details
- Locator Mk.II EPROM cartridge emulator – a replacement EPROM cartridge which allows fast-turnaround firmware patching and debugging.
- Network Simulator – generates signals which simulate a network of Datatrak transmitters.
- Software tools – for analysing the network based on data obtained from Locators
- References – other sources of information
Media coverage
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