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Electronics => Electronics => Topic started by: TrickyNekro on March 04, 2009, 05:37:04 PM

Title: OMFG!!!!! Look at that range!!!!!!
Post by: TrickyNekro on March 04, 2009, 05:37:04 PM
http://www.sparkfun.com/commerce/product_info.php?products_id=9086 (http://www.sparkfun.com/commerce/product_info.php?products_id=9086)
No words.... No....



Sorry for shouting....

Lefteris
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: Canabots on March 04, 2009, 05:55:11 PM
http://www.sparkfun.com/commerce/product_info.php?products_id=9086 (http://www.sparkfun.com/commerce/product_info.php?products_id=9086)
No words.... No....

GASP!!!!!! Ditto!!!!!! :o

Wow! That price doesn't look too bad either! This would be awesome for anyone doing some sort of exploration robot. This probably opens up lots of possibilities for UAVs too!

WOW!

Canabots
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: airman00 on March 04, 2009, 06:01:55 PM
holy crap
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: Razor Concepts on March 04, 2009, 06:19:06 PM
Line of sight.. even small obstacles will block the signal. I have trouble imagining 100mw traveling 15 miles?? Maybe in the desert or something.
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: TrickyNekro on March 04, 2009, 07:04:03 PM
Sure... But with a air UAV it's far useful....
Even 200m without line of sight is very good for a ground vehicle....

I'm gonna get some and test 'em....
Bad thing antenna comes extra.... :P
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: Hawaii00000 on March 04, 2009, 10:45:07 PM
Excuse my ignorance but ummmmm whats it for? Is it some kind of wireless serial transmitter?
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: cosminprund on March 05, 2009, 02:38:31 AM
Quote
The modules are optimized for use in US and Canada.

Is that a nice way of saying those modules are illegal in Europe? We've got GSM Cell networks on 900Mhz.
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: Soeren on March 05, 2009, 02:57:02 AM
Hi,

Yes, they'll probably be illegal in Europe.
Don't see why anyone would buy them though - two old cell phones (can be found in dumpsters sometimes) and a bit of hacking, and you have a 2W encrypted link :D
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: airman00 on March 05, 2009, 06:52:07 AM
two old cell phones (can be found in dumpsters sometimes) and a bit of hacking, and you have a 2W encrypted link :D

with or without paying monthly for service?
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: paulstreats on March 05, 2009, 07:10:51 AM
without paying, the radio modules can be used independantly. The paying part is contained within the phone companies communications software layer.

the radio modules would normally connect straight to a proper transmitter / receiver station which then routes your call either through existing land lines or satellites. its only here that you are using their service. so if you dont let the radio module connect to the station then theres no need for any charges cause youre not using their services.
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: Soeren on March 05, 2009, 04:16:45 PM
Oh well, there's still one charge remaining... Your batteries   ::)
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: airman00 on March 05, 2009, 04:19:15 PM
without paying, the radio modules can be used independantly. The paying part is contained within the phone companies communications software layer.

the radio modules would normally connect straight to a proper transmitter / receiver station which then routes your call either through existing land lines or satellites. its only here that you are using their service. so if you dont let the radio module connect to the station then theres no need for any charges cause youre not using their services.
any resources online for it?
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: HDL_CinC_Dragon on March 05, 2009, 10:00:21 PM
It just so happens I have 3 or 4 old cell phones sitting on my shelf across the room right now :D Please have some good links PaulStreats :)
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: tralfam on March 06, 2009, 05:32:49 PM
Hi,

Yes, they'll probably be illegal in Europe.
Don't see why anyone would buy them though - two old cell phones (can be found in dumpsters sometimes) and a bit of hacking, and you have a 2W encrypted link :D


Are any good write-ups on how to do this available? It sounds intriguing.
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: Soeren on March 06, 2009, 10:35:25 PM
Hi,

Are any good write-ups on how to do this available? It sounds intriguing.
I have seen a few on the net years ago, but don't know if they're still around. However, it's just a matter of whether you can find datasheets for the chipsets.

Another source for long distance UHF TX/RX is PMR's, some of them are sold as being able to do 8 km (in open country).
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: TrickyNekro on March 07, 2009, 06:55:59 AM
I hate it to say again.... but.... links!!!! please!!!
That mods are very very nice!!!!!!!
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: Admin on March 25, 2009, 12:23:12 AM
Hmmm, despite the 'up to 15 mile range', it says '9.6 kbps throughput data rate' . . . impressive range, but you can't transmit much at that data rate . . .

But hey, transmitting GPS coordinates to find your UAV after it runs away could be useful!
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: Asellith on March 25, 2009, 05:54:31 AM
umm hacking old cell phones to transmit your own data is illegal. Using the cell phone with a carrier is ok because they have the license to transmit on those frequencies. Once you start hacking it to send your own signals then your gonna confuse cell towers and provide noise on those frequencies. Then the cell company is gonna investigate who is transmitting on their stuff and using really cool equipment (I have played with some of it) find you and then call the cops. Unless the FCC finds you first. That and cell phones use GSM or CDMA encoding so unless you encode your data into one of those protocols then your not going to get anything on the other end. Not sure about GSM but when your cell phone transmits it uses a bandwidth that is huge and spreads the signal over a large area then uses complex math to extract the signal from the noise. You put a standard signal in that bandwidth and every cell phone in the area will be get interference.
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: MaltiK on March 25, 2009, 06:39:57 AM
Such an interesting subject, and I dont see how it is illegal if you are not using their pay-as-you-go service.
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: Asellith on March 25, 2009, 07:38:08 AM
We are talking about hacking the radio to transmit a different signal. As it is now the signal is sent out and captured by a tower then routed and sent to the second phone. This takes their system and paid services. Now you hack the phone and build a transmitter/receiver pair out of them. This sends illegal signals inside their protected bands. That is whats illegal. Not the hacking but the transmitting. Same as if you reconfigure your ham radio equipment to broadcast at 89.5 Mhz in Pensacola, Fl. then I come hunt you down and send the cops after you because I have the legal right given by the FCC to broadcast in this area on the frequency. Well my company has the right not me personally but you get the idea. Even if no one is using the frequency they are protected by the FCC. Only a few frequencies are open to transmit on and most of those require a license with the exception of CB but only a low wattage.
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: Soeren on March 25, 2009, 10:15:06 AM
Hi,

umm hacking old cell phones to transmit your own data is illegal.
So is making transmitters for eg. the broadcast band (like bugs), but that doesn't seem to stop people doing it.


Once you start hacking it to send your own signals then your gonna confuse cell towers and provide noise on those frequencies.
Noise?
Towers ain't gonna be confused, because you obviously change the frequency (else you'd get interference from any phone happening to be using "your" channel at the time).


Then the cell company is gonna investigate who is transmitting on their stuff
They couldn't care less, as long as you don't interfere with their service, which you don't.


and using really cool equipment (I have played with some of it) find you and then call the cops. Unless the FCC finds you first.
It's gotta be, not just clever, but really really clever, since GSM, CDMA etc. transmit in short bursts.


and cell phones use GSM or CDMA encoding so unless you encode your data into one of those protocols then your not going to get anything on the other end.
Nonsense, you use the two phones own circuits, no big deal.


Not sure about GSM but when your cell phone transmits it uses a bandwidth that is huge and spreads the signal over a large area then uses complex math to extract the signal from the noise. You put a standard signal in that bandwidth and every cell phone in the area will be get interference.
GSM, CDMA, GPRS etc. are what's used for ell phones, are you perhaps referring to very old and outdated technology with your term "cell phone"?

Still, it's nonsense.
First of all, it is not allowed to use a "huge bandwidth", second, it would be a waste of power - on the contrary, it uses a narrow bandwidth.
Cell phones are very resilient to interference and noise on the input, due to clever software - perhaps you confused "receive" and "transmit" ?
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: jsmoker on March 25, 2009, 12:04:20 PM
Hmmm, despite the 'up to 15 mile range', it says '9.6 kbps throughput data rate' . . . impressive range, but you can't transmit much at that data rate . . .

But hey, transmitting GPS coordinates to find your UAV after it runs away could be useful!

Ditto on that.  Especially if you're trying to get any real time sensor data.  But the thought of a 15 mile range is pretty cool.
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: MrWizard on March 25, 2009, 01:43:19 PM
Oh well, there's still one charge remaining... Your batteries   ::)

Thats correct they are illegal in Europe, in a lot of countries more also. Maximum power allowed in Europe is 100mW (free)  above these figures you are going to need a permit.
900Mhz is the old GSM network, but still in use....
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: Soeren on March 25, 2009, 05:59:26 PM
Hi,

Oh well, there's still one charge remaining... Your batteries   ::)

Thats correct they are illegal in Europe, in a lot of countries more also. Maximum power allowed in Europe is 100mW (free)  above these figures you are going to need a permit.
900Mhz is the old GSM network, but still in use....
I fail to see the connection with the quote from me?

Sure it's illegal, like bugs which, for some reason, is one of the most wanted circuits world wide for strange reasons - it's rare to find a request for a small receiver to go with it.

*Phew* sure glad I didn't post schematics for a cheaply build transmitter/receiver pair for data comms - wouldn't wanna offend any -pushers.
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: Admin on April 08, 2009, 12:29:46 AM
Just so everyone is aware of this - in the US you are allowed to transmit anything on any frequency if:

- its a short term one off experiment (such as for hobbyists)
- it causes no serious interference, or interference is minimized best as possible
- it in no way interferes with emergency service frequencies and systems

For example, you can block cell phone transmissions if it lasted just a few minutes, is considered an experiment, and its done where the likely hood of it disabling emergency phone calls is minimized. But it'd be illegal to do it long term and/or with the sole intention of causing interference.
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: TrickyNekro on April 08, 2009, 04:54:06 AM
That's why they can only nag about 2.4GHz model pilot systems...
They are interfere with WiFi companies selling internet on wifi....
But since 2.4GHz is a free band.... Not exceptions...
I think that a 800 something or a 900 something frequency that it's close to mobile freqs...
is open... take an example ZigBee modules...
And ZigBee Pro is supposed to have some miles range...
Since frequency pollution is great in many many countries, only smart software can
solve the channel problem...
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: airman00 on April 08, 2009, 09:08:36 AM
That's why they can only nag about 2.4GHz model pilot systems...
They are interfere with WiFi companies selling internet on wifi....
But since 2.4GHz is a free band.... Not exceptions...
I think that a 800 something or a 900 something frequency that it's close to mobile freqs...
is open... take an example ZigBee modules...
And ZigBee Pro is supposed to have some miles range...
Since frequency pollution is great in many many countries, only smart software can
solve the channel problem...
ISM Bands are free for everyone - http://en.wikipedia.org/wiki/ISM_band (http://en.wikipedia.org/wiki/ISM_band)
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: paulstreats on April 08, 2009, 09:44:00 AM
There is a book called "hacking mobile phones" that goes through how to independantly use their radio modules explaining the concepts and that most people dont realise that they are only radio transcievers.

Any web searches just seem to pull up bluejacking techniques or ways to hack into non existent fictional free bands for phone calls (no matter what radio band you use, when the phone registers at the station and makes a call request you get charged). Hacking the actual radio transcievers for direct communication seems to have faded away into history... probably because hacking them can give terrorists an untraceable remote detonation unit
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: frank26080115 on April 09, 2009, 10:50:38 PM
We are talking about hacking the radio to transmit a different signal. As it is now the signal is sent out and captured by a tower then routed and sent to the second phone. This takes their system and paid services. Now you hack the phone and build a transmitter/receiver pair out of them. This sends illegal signals inside their protected bands. That is whats illegal. Not the hacking but the transmitting. Same as if you reconfigure your ham radio equipment to broadcast at 89.5 Mhz in Pensacola, Fl. then I come hunt you down and send the cops after you because I have the legal right given by the FCC to broadcast in this area on the frequency. Well my company has the right not me personally but you get the idea. Even if no one is using the frequency they are protected by the FCC. Only a few frequencies are open to transmit on and most of those require a license with the exception of CB but only a low wattage.

Question, hypothetically, if you were a radio station and somebody who doesn't like you broadcasts on your frequency (completely overpowering your signal within 1km of his house, lets say), what would the response be and how fast would it be? I mean, would it be the police who get involved? Would they make an arrest? Immediately?
How fast can you pinpoint a location and what kind of evidence do you need before anything is done about it?
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: Admin on April 10, 2009, 12:07:48 AM
Quote
Question, hypothetically, if you were a radio station and somebody who doesn't like you broadcasts on your frequency (completely overpowering your signal within 1km of his house, lets say), what would the response be and how fast would it be? I mean, would it be the police who get involved? Would they make an arrest? Immediately?
How fast can you pinpoint a location and what kind of evidence do you need before anything is done about it?
I don't know the whole answer to this, but I know part of it from experience . . .

When I was young (12 years old? don't remember) I found a schematic for a frequency jammer. I quickly figured out how to tune it with a pot to jam radio stations of my choice. Then I learned that hooking up a 40 ft antenna to it gave it incredible range . . .

To jam properly you need a radio listening to that channel, so when I turn my jammer on I can hear the radio stop working. Well after playing around with it for 30 or so minutes the radio channel suddenly stopped playing music.

Instead it played loud tonal beeps and said something like 'testing service' or something like that. I assume they were trying to figure out what the interference was and localize it, too.

I never tried that again . . . :P
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: Asellith on April 10, 2009, 07:21:59 AM
Well to tell you the truth it depends on the radio station. Commercial Band broadcasters would do more contour checking then I would working at a Non-Commercial station. It would depend on listenership as well. If one of my listeners calls me and says they get nothing but static or someone else is broadcasting on my frequency then I would get involved. I don't have the equipment to locate a rouge transmission but I could get it easily enough. Or use my spectrum analyzer I do have and play with it a bit to get a bearing on the transmission. And yes if I find the location of a pirate broadcast I will call the cops. A pirate station in Orlando just got busted a few weeks ago. These pirates last a few weeks maybe a month or so and run like a normal radio station except for the government regulations so their overhead is lower. That and they don't pay royalties. Some don't make money but others actually have advertisers and make some cash along the way.

The hardest part about finding the rouge transmission would be knowing it existed. I cover a large area in 4 different states. I can't drive that distances on any normal basis. The most I do is a yearly contour check and that just on the major highways in 3 directions. (ocean is to the south so no checking that direction)

Again if a listener complains I think even without the best equipment I could find you in less then a week. Maybe even one day. I one of the guys here is a ham and if he puts the word out I bet we could have some bored ham junkies tracking for us as well. In a rural area where your going to affect like 5 people you might never get caught. In downtown Pensacola or Mobile, I'd find out rather fast and cops would be involved.
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: Admin on April 10, 2009, 09:38:21 AM
Asellith, whats the accuracy of this tracking, and how exactly does it work? Some form of triangulation?
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: TrickyNekro on April 10, 2009, 10:34:31 AM
Wouldn't UAV help this job....
It's quite difficult with all those reflections get the transmitter, thus you need a week....
I think UAV like these are being used by Israel to destroy mobile radar stations....
So technology exists!!!
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: BANE on April 10, 2009, 02:23:51 PM
"15 miles"

Do you have to get some special antenna to get that range?  I have a wireless PS2 controller; is it possible to up grade the RF module or can you do that with this?

Bane
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: Asellith on April 10, 2009, 03:06:22 PM
I've never had to do it but as far as I understand it you take a special antenna that attached to a mobile spectrum analyzer. Then you can figure out peak power output from one point and get a bearing then triangulate from several points based on signal strength. The antenna is basically a directional antenna that when pointed that gives you the ability to get a bearing. More advanced guys use antenna arrays and triangulate on the fly. I have seen some crazy Ham setups mounted on cars to chase signals. Evidently its a sort of game they play sometimes. One guy will put a transmitter up and others try and find it. Or he will mount it to a vehicle and drive around till they trap him.

TrickyNekro is right about the reflections but most of the time they are such small wattage TPO (Total Power Output) to begin with the reflections are a lot lower in power. Tracking my 95kW transmitter might be rough if it was in the middle of a city (its in the middle of nowhere) You'd get reflections that where close to that wattage all over the place because of reflection. But a guy transmitting a pirate transmission will not have that kinda wattage.
Title: Re: OMFG!!!!! Look at that range!!!!!!
Post by: Soeren on April 11, 2009, 02:14:18 PM
Hi,

[...] what would the response be and how fast would it be? I mean, would it be the police who get involved? Would they make an arrest? Immediately?
How fast can you pinpoint a location and what kind of evidence do you need before anything is done about it?
The speed of response will depend on a mixture of the owner of the radio station, how fast listeners report the interference etc.
Somebody will come knocking at your door pretty soon and they will bring the law, you'll be booked and your equipment will be confiscated down to the last power supply component.
It's very easy to use triangulation to pinpoint a jammer with a constant carrier.