[el mechanico]

Today I got the cell jammer. It worked when it was right next to my phone but would not work when when it was 2 ft away. My employees have Sprint android phones and I have an ATT Iphone.
I even had two people call me with cheaper metro pcs phones and it would not break the call from 5 ft away.
Im bringing it with me to the DMV right now to test it again.
Sorry for the news...

[Tuthmosis]

That sucks! I was hoping that inexpensive model would do the trick. It could be that the newer-model phones simply outwit it. We may have to try the home model one of the other cats was using.

[el mechanico]

It did'nt work at the Dmv or the smallest Mexican place I had lunch. It would'nt even scramble the wireless land line.
It was worth the excitement of opening the box for $20 I guess..

[Kickb]

aw, that sucks. we had such high hopes for it too

[thegmanifesto]

el -

Did you try this one:

http://www.jammer-store.com/albatross-gs...ocker.html

I am not giving up hope on this.

This one:

http://www.jammer-store.com/mgt40-deskto...ocker.html

Says 40 meter radius.

I might have to bring that desktop model into a bar.

[el mechanico]

Last night was a cellular disaster. I am going to do some serious research and make sure I find one that works good.
I had an issue with the size of the one I ordered. I want to find the smallest strongest one possible. It was awkward when I was reaching in my pockets to get cash and when I had to run after a shopping cart that was ready to dent my car. And that was only one outing.

[oldnemesis]

(07-13-2011 12:42 PM)el mechanico Wrote:  

Today I got the cell jammer. It worked when it was right next to my phone but would not work when when it was 2 ft away.

This is a typical case. However there are four questions.

1. How did you test it? Some people make a mistake by testing the jammer by watching the reception level on their phone. This is a mistake. The base station has a much stronger signal than your jammer (or it would be dangerous for you to carry it), so what jammer does is interfering with the phone transmission. So don't just watch the antenna on your phone display, try to make a call.

2. Most GSM jammers I've seen transmit on 900MHz, which is Europe/Asia GSM frequency. However most US operators use 850/1900MHz, so if yours transmits on 900, it will only work very close to the phone (like 1/2 feet or so).

3. The coverage area of a transmitter does NOT look like a plain circle. The worst reception is usually NEAR the transmitter. Meaning the signal may be weak 2ft away, but strong 4ft away. This could be adjusted with antenna, however it is pretty much impossible to have flat coverage from a non-stationary device.

4. Unfortunately making a jammer which would transmit on two frequencies at the same time, fit into a small box less than your Wi-Fi router, surviving reasonable time on regular batteries and fitting into the amateur budget is pretty much impossible. So you'd have to choose between high-quality equipment designed for law enforcement (and its the price tag; also most models I've seen look like a boombox so while portable it is not something you can pocket), or crappy Chinese-made jammers. The last one usually ends up in one of following ways:

1. It will die in ten minutes after it drains your battery completely.
2. Once you put a better battery, it will die after working for twenty minutes because the transistors/IC in output cascade overheat. Chinese guys are notorious at saving money on heatsinks.
(both items 1 and 2 assumes a properly designed device which generates good output, which is rare).
3. It will work the same way as yours, i.e. transmit using the maximum legally permitted power, making it useless 3ft away.

Unfortunately there is no silver bullet.

[thegmanifesto]

Any update on this?

I would like a sure fire solution for when I get back to Acirema.

[oldnemesis]

G, if you have contacts with the companies which sell equipment to law enforcement, talk to them. Their equipment is top notch, and it does the job. Just don't expect it to be pocket size (and of course it won't be cheap).

[Andreas]

How much money would i earn if i made a prototype cell phone that jams any other cell phone? Someone said that today people learn to use their cellphones better than their brains. So it should sell a lot to people who do use their brains.

[el mechanico]

Old nem is right. These things need power to work and will be big.

Now that this is in my head i see that cell phones are fucking up me getting laid continuosly.
I was fighting with this girl on my boat yesterday who kept pulling it in and out of my dry cooler where my phone was and told her to keep it somewhere else because I wont touch mine on the water. in case of an emergency it has to work and be dry and charged (she was getting salt water in my dry cooler)
Needless to say her android is now trash and she went fucking ballistic and had a total meldown, fell off the boat etc.

[oldnemesis]

(07-24-2011 10:45 PM)Andreas Wrote:  

How much money would i earn if i made a prototype cell phone that jams any other cell phone?

They are easy to develop - a couple of ICs and some logic, so don't expect to get the Nobel prize for it. The main problem is to keep it small, powerful and covering all frequencies. Those can be resolved, but it won't be cheap and it won't be a device you could (or would want to) carry in your pocket.

Note that those devices are already available, they're just not being sold to the general public (but you won't be able to sell it to general public either), because this is a transmitter, and to use a transmitter you have to get a license from FCC for those frequencies, which you obviously won't be able to. They're however quite often used by law enforcement, some private investigators, and of course military.