High Power 800 MHz/AMPS Cellular Phone Jammer
This is an outdated project.
It is possible to build an AMPS cellular phone system jammer using commonly available parts. This will only work with the older, analog 800 MHz cellular phone system and is for reference only. The theory is to generate a signal that is in the same frequency band as the phone is operating in, but at a much higher power than the normal received phone signal. Sweeping that signal across the entire cellular phone band will jam any phone in the immediate area.
The most important part of the jammer is the initial RF signal source. Generating the RF signal is very easy today with an IC from . The MAX2622 is a monolithic voltage-controlled oscillator that covers the frequency range of 855 MHz to 881 MHz. Review the datasheet (151k PDF) then order a few MAX2622's from Maxim directly. The device is in a tiny little 8-pin µMAX package, so you may want to mount it on a SurfBoard from , part number 33108CA-ND, to make it more easy to work with. Note that you'll need to glue a copper ground plane to the bottom of the SurfBoard using a scrap piece of copper clad PC board material. Drill the ground vias as needed.
The next part of the jammer is the sweep generator circuit, this can surprisingly be built using (mostly) parts from . It's just a twin-tee tone generator buffered/amped by a LM1458 op-amp. This outputs the sweeping voltage that connects to the MAX2622's voltage tune pin.
You'll also need to aquire an old bag-style cellular phone (Nokia/Tandy/Uniden are best) for it's power amplifier module, usually a PF0030. This will be the intermediate power amplifier and will drive the final power amplifier. There are a few possibilities in this stage and they will be described later.
Jamming distance depends on RF output power and antenna. Doesn't work on those PCS phones (yet!)
Additional Notes
Can also be used to jam 800 MHz trunking and SMR radios (i.e. racist cops) and will do a little damage to the 900 MHz ISM band.
The third harmonic of a sweeping 800 - 828 MHz signal will jam devices operating in the 2.4 GHz ISM band. Great for taking out overzealous ISPs.