Science Info

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Cellular Phone/GPS "Burs

t" Tracking Device Jammer

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Developed for GBPPR's Directorate of Operations case officers operating out in the field, this device uses a neat little trick to j

am most of the common cellular modem (CDPD or analog AMPS) controlled GPS tracking devices.

First, a custom cut Fox 225.06 MHz clock oscillator is filtered with a 1575 MHz GPS bandpass filter isolating its 1575.42 MHz 7^th harmonic. This harmonic is further amplified and sent to a small, low cost, surface mount antenna. This produces a limited range continous wave (CW) jammer centered on the GPS L1 frequency.

This jammer only has an effective range of a few meters and only jams the lower-cost standard positioning service (SPS) GPS receivers.

Second, a common 45 MHz clock oscillator drives the local oscillator port on a Mini-Circuits mixer. The RF & IF ports and connected to two small, low cost, surface mount 800 MHz antennas. Here's the trick, any cellular phone that attempts to call out is "jammed" by its own signal! This works because the phone's transmit and receive frequency are always separated by 45 MHz.

Example: your phone transmits on 837 MHz and receives at 882 MHz. If you were to mix the 837 MHz transmitted signal with a 45 MHz signal, the new mixer output frequency would be 882 MHz - and the phone would essentially jam itself.

This is very useful against "burst" tracking devices which may record your movements for a week or so at a time, then wait until 3 A.M. when your sleeping to burst out a quick phone call to KGB headquarters to upload the tracking data. It also prevents any computer record of phone calls or RF direction finding of the phone's signal from revealing your location.

This jammer also only has an effective range of a few meters (if that) and only jams analog AMPS cellular phones or CDPD modems.

This jammer should also work on the General Motors' (GM) OnStar Navigation System. The unit I saw utilized an old Motorola AMPS phone for communication.

Schematic

• Cellular Phone/GPS "Burst" Tracking Device Jammer Schematic (57k PNG)

Device for Detecting GPS Receivers

Here is an example of using an old AM radio to detect GPS receivers.

• Device for Detecting GPS Receivers

Simple 800 MHz Cellular Phone Jammer

Passive cellular phone jammer.

• Simple 800 MHz Cellular Phone Jammer

There is NO Monthly fee, and never any service fees. With the Ti-GPS you are always able to receive free worldwide GPS tracking using the American GPS satellite networks.

Many people are misinformed on the topic of GPS, fully unaware there is in fact no monthly fee for GPS access. Something which can be fully realized with the AyAy Sir Ti-GPS receiver. The advertising of many other automotive GPS navigation systems suggests otherwise, requiring monthly access fees. This is a fairly common misconception, one which needs to be laid to rest. GPS(Global Positioning System) was designed for and is operated by the US Military, and is entirely funded and controlled by the US Department of Defense. GPS satellite tracking signals are offered as a FREE public service by the American Government, and are a free resource regardless of the application, be it piloting, sailing, or driving. There are absolutely NO monthly fees or setup fees required for access to GPS tracking signals.

Pictured is a Sony VAIO laptop equipped with the AyAy Sir Ti-GPS, allowing it to function as a full fledged 3D GPS navigation system.

The Open GPS Tracker is a small device which plugs into a $20 prepaid mobile phone to make a GPS tracker. The Tracker responds to text message commands, detects motion, and sends you its exact position, ready for Google Maps or your mapping software. The Tracker firmware is open source and user-customizable. This looks like a great project if you’re into GPS projects.


source:http://www.youritronics.com