Sticking with the mobile phone theme, here’s a cellular phone (or mobile phone) radio signal jammer, designed to knock out phones in a 15 metre radius. The unit features a rechargeable battery and will run for 90 minutes on a single charge.
The jammer has 3 aerials to match the 3 frequency bands it’s designed to block out. If an aerial does not match the wavelength (and thus frequency) of the transmitted radio signal, then the strength of the signal can be severely limited. Therefore to maximise the output of the device, the jammer has an aerial length that matches the average frequency of the major frequency bands.
The jammer is intended to block out the following frequencies:
- 851 – 960Mhz
- 1805 – 1990Mhz.
- 2100 – 2170Mhz
However, if you look at the commonly used frequencies on the GSM frequency band allocation:
- GSM900 -> 880 – 915 MHz paired with 925 – 960 MHz
- GSM1800 -> 1710 – 1785 MHz paired with 1805 – 1880 MHz
- GSM1900 -> 1850 – 1910 MHz paired with 1930 – 1990 MHz
GSM900 and GSM1800 are typically used in Europe, and GSM1900 is typically used in the US. You’ll notice that GSM1800 is not completely knocked out. The 1st set of frequencies on GSM1800 do not fall within the specified range on the jammer. However, GSM900 and GSM1900 are completely covered by the jammer. I wonder if the jammer does completely knock out service providers using GSM1800?
However, it’s illegal to own and use a frequency jammer in Europe, and some parts of the US too I imagine. You’ll notice that Spy Catcher will not sell a jammer to anyone in Europe. Considering they are based in the UK, I wonder if they stock the devices in the UK. Remember, it’s illegal to own one!