LimeSDR Jammer


I was watching some YouTube videos on SDR and like usual fashion ended up “drifting” to other topics. Was watching a video on wifi jammers and then it dawned upon me, and hence my question… couldn’t the LimeSDR with it’s wide 60+MHz transmit capability be able to jam say wifi (i.e. 2.40-2.46) or RC model signals or even cell phone signal, especially if an amplifier was installed on the output connector?

Before everyone gets their panties in a knot on how illegal this is… this is simply an intellectual exercise.



Yes, LimeSDR can jam signals. Simplest way to do a jammer is to transfer a noise signal in GNU Radio on a frequency you want to jam.


So, what I’m wondering is will LimeSDR transmit that noise over the whole 60+MHz at once, so that the waterfall plot is one large noise plot? Also, I’ve been reading that the LimeSDR is actually capable of receiving/transmitting over 80+MHz and upto 120MHz, is that true?


I think what he’s getting at is what is the widest bandwidth that the unit can transmit?

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I have been able to receive and transmit two separate 40MHz bands that are 10MHz apart. That 90MHz could be just about anywhere in the range of the device, I would think.


Somebody nearby has a heart attack, while you are playing around jamming mobile calls. You are directly blocking their access to medical services, you could potentially cause someones death.

It is not just illegal, it is socially and ethically wrong.

EDIT: I see the OP’s question in the same light as I would someone asking how to dump raw sewage into the communal local water supply. It may be ridiculously trivial to do, but I am not going to answer it.


Imagine, drone flying over-near the forest fire so super scooper CL415 is not able to operate
and someones house is just about to catch fire…
How about that case regarding wrong and right / socially and ethnically ?!

So much better to go back on technical topic…


There are plenty of legal application for such a use case besides jamming, no need to attack the OP for asking.
Also I personally would like to know as well, how wide can you get this thing to transmit.
Plenty of SHF and higher apps for that too.

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Sometimes a friend comes to visit my house and answers a social call whilst we were chatting. He’s on the phone for 5 minutes making me feel slightly annoyed. He does not have the decency to leave the room. Since I actually like this person and don’t want to offend him:

In this case, I’d quickly switch on my LimeSDR, with a transmit range of 5 metres, and make it send a sine wave sweeping rapidly and repeatedly through all the local cell phone base station Tx bands. Alternatively, and probably more effective, I’d upconvert neighbouring white noise into the whole base Tx band, one band at a time until I’d worked out which band his phone was on.


Sawtooth waves work better, academically.

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So simply clarifying a transmitters capability is akin to causing bioterrorism? Thats a little bit over the top dont you think. The device is a USB powered SDR. Its not running 4 Svetlana’s or even 1 for that matter. The man is asking a simple clarification on the specifications of a device he has or is purchasing. I myself would like to know how clean the device transmits, and its transmit capability. EW, ECM, ECCM, Tempest, are all subjects I am interested in and have maintained, being a retired R.A.N ET-C Rate, and as a Full Call Amateur Radio Operator who pays for his Licence every year on cue, I like to ensure my foot print is as small as posible. Being curious is part and parcel to Amateur Radio and if it wasnt for this curiousity, no one would have found out that a germanium cats whisker could demodulate an am transmission. In the last 12 months in Australia, we have had multiple attempts by prisons, to Jam Cell Towers such that prisoners who manage to illegally receive mobile phones in maximum security prisons, cannot use them. Each time the ACMA knocks back the request to jam. Jamming in itself, in that case is the dumbest thing to do. Firstly, if each prison cell was its own Faraday cage, there would be no problem, secondly, running a pico-cell would give you more information on these criminals than you could hope to achieve, from an ELINT view point. Ive worked in more vaults and faraday cages than I can count. Ive been jammed. Trust me, a USB SDR with an FPGA didnt do it. I am not saying that one cannot emit a harmful signal at a frequency that can interfere with bio-electronic medical devices with an SDR. But the dose makes the poison, proximity, directionality, and power are all factors. And if a USB Powered SDR is capabable of misfiring a pacemaker, or other type of implant, than does that not highlight a significant failure by the manufacture to protect against such attacks. Anyone driving to an airport, with Air Search Radar, could drop dead, same as anyone driving past the log periodic towers in certain locations, repeater stations, cell towers, and the list just goes on. One harmonic retransmission, could cause in theory a failure of such a bio-electronic medical device. Joe blogs having a play in his shack is hardly going to kill granddad or nanna. Necessity is the mother of invention. How many people who will purchase a Tx capable SDR whether it be LimeSDR, HackRF, BladeRF or other, actually have an Amateur Radio Licence? I could sit here all day and compliain about the number of SDR users who may not be licenced operators. What good does that do me? Nothing. I could sit and complain about the number of Racing Quadcopter/Hexacopters etc, that are Tx-ing on 5.8GHz in contravention of current power limits for non amateur operators. Thomas Jefferson once said [sic] “What do I care that my neighbour might believe in more than one God, it does me no damage” (Or words to that affect). The answer to the Jamming Question is undoubtedly yes. The Effectiveness (Without a frequency specific Antenna and Amplifier) is marginal/neglible at best. Operating it in any mode, on a frequency that might affect a pacemaker or insulin pump or some other device, without actually trying to jam it, may affect it without you trying. Thats why the ACMA in Australia, and the FCC along with the ARRL in the USA have BandPlans. And despite the morality pedestal, it takes a penetration tester, to ensure companies ameliorate the security of their products. If it wasnt for hackers, nobody would be able to get their money out of a bank, as it has been White Hats that have helped Governments and Corporations secure their data. I just dont get how one can come to a conclusion that asking about jamming is like committing bio-terrorism. That one has me stuffed. And as we Aussies sometimes say, fair crack of the whip!


Too Funny!!!


I am glad that you were suitably entertained. I’m sure I will never actually get round to doing this jammer project. I think it would be better just to tell the guy to go outside.


Believe me, theres been plenty a time, Id like to have EMP’d my next door neighbours stereo, or when I lived in the city, a directed EMP at certain nightclubs and bars keeping me awake til 0400hrs on a Monday morning. The problem with that, is having to build a faraday cage to save everything you own that you dont want to fry. And, directed energy systems are kinda loud, so getting missiled by my own warship wouldnt have been a good look, just to take down the bar across the street.

Oh and by the way, you could probably achieve what you want to do in that respect with multiple CC1101 Wireless RF Transceiver 315/433/868/915MHZ modules.

Here is an example of a 2.4GHz Jammer for Wifi

Im sure that one works, not too sure about this one though

Whatever floats your boat, caveat emptor I guess. Youtube is full of projects on jamming and creating EMP devices.

Whether legal or not, probably not a good idea to take it through the Xray machine at the airport. Just sayin :slight_smile:

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Yes, I would like to know has well the max TX bandwidth or it’s even possible at all. This could be used to make really interested things like active monitoring of all 13 wifi bands at the same time, a thing we can’t do with usual wifi cards.