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Cellular Phone Blaster...

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Advanced Member level 4
Mar 14, 2002
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I posted this topic a year ago and never got an answer. Elektroda family has grown a bit, maybe we have the knowledge now...

I need a simple enough circuit to seriously disturb a cellular phone reception to make it loose the caller. I intend to use it in my car to cut the reception of a driver that does slalom (ski term) with his car while on the phone.

Can we just transmit a high amplitude and disturbing square wave around the cell frequency? I know there are not just one freq, but a big carrier could mess with the cell freq locking...

Any suggestions?

It can be done but is illegal

This is technically possible, but very illegal at the federal level. You would also block other calls which may be of importance or even emergency level.

you must transmit a broad band signal to cover the whole GSM,PCS band

Not easy, illegal, but possible

Transmitting without a license in a frequency band somebody has paid money for is illegal. Blocking is possible, but not so simple.
Typically a cellular network has a very large variance in the link margin. This means that at some places you need very little extra noise to block, and at other places you'll need to add a lot of noise.
What you may attempt to do is to take advantage of the fact that you are much closer to the cell-phone than the base-station transmitting to it, and you also know the direction to it.
Try transmitting amplified noise. Use a directional antenna with very narrow horizontal and vertical beam-width (NOT an omni) and point it at the cell phone you want to interfere.
This way you will interfere less with other phones, and also direct all your power where you want it to go.
If you transmit enough power (when enough depends on the local link margin), you'll cause the cell phone to lose the base-station.

Thanks for the help.

BTW, I know that interferring with cell reception is illegal, but it's not like I'm going to jam the overall city for a long time. I need something that can jam the cell for a couple of seconds. Just to be annoying...

The directional antenna is a good idea...




tanveerriaz said:

Directory is there, but file not found... :(


here you have guys.... but this works only on 800 MHz ... GSM network works much higher around 900... If you can do something with that please let me know...

Does somebody try this circuit and get some result?

Where is the key point?

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