Tracking Device Teardown | Hacker News Reader

Tracking Device Teardown

ifixit.com

83 pointsaburan289 comments

As well as the teardown, the disclaimer is pretty interesting too:

> We love the FBI. We've worked with them on several occasions to fight crime and locate criminals. We've helped them with instructions on gaining entry into certain devices. We have nothing against them, and we hope they don't come after us for publishing this teardown.

This doesn't have a date on it, but the corresponding blog post suggests 2011: http://www.ifixit.com/blog/2011/05/09/fbi-tracking-device-te...

It's history (https://www.ifixit.com/Guide/history/5250?page=3) shows the first edit to be on April 13, 2011 @ 3:31 PM.

The accompanying wired article (http://www.wired.com/2011/05/gps/) was published May 2011, says the device was found in 2005, and the teardown suggests parts were as old as 1999.

Anyone else wondering where all the transponders are located ?. I would have expected a tracker to piggy back on cell towers so that they could use existing infrastructure but that probably doesn't work from an intelligence standpoint.

It works fine and this is commonly their connectivity arrangement. This one is remarkable because it has some UHF radio hardware. They don't need to have a network of transponders: one will work just fine if the victim regularly comes into its proximity. At those times it can be queried for position information.

What do you think the range on that transmitter would be ?

According to the datasheet [1] the transceiver outputs -5dBm. (This is 5dB less than 1 mW.)

This specific device is not analyzed enough to reveal whether or not there is an additional amplifier, which "could" be made from a single transistor and some passives.

Assuming that there is no amplifier, and taking into account the short wire antenna and detrimental environmental conditions, I feel safe guessing the upper bound of useful range will not be more than a 250 m distance. Probably it's half that.

I will also guess that the fixed part (you can call it a transponder or base station) will not have power budget to worry about so it will periodically be announcing itself (you don't want the mobile part to do this because it will consume the battery.) The mobile part will answer when it hears this transmission. If this is true, then a TSCM beginner will be able to play "find the beeper" pretty easily.

[1] http://www.datasheetarchive.com/dlmain/Datasheets-40/DSA-798...

Too bad that there aren't many details on the wireless link (e.g. frequency, protocol)

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