SDR thread

>>60751479
>Software Defined Radio anyone?
I bought a LimeSDR weeks ago and this device is really great. I will be doing my own 4G base station soon. What device do you have and what SW are you using?, I prefeer GNU Radio and Matlab.

>>60751479
BladeRF I started by making my own stingrays on it, now I'm looking for other fun projects.

just bought one of those and looking forward to examining signals around my home. probably going to invest in a couple more so i can do signal triangulation.

>>60751622

what's the learning curve like for gnu radio?

i was debating which one of the transceiver sdrs to get and it's down to hackrf, limesdr, bladerf and usrp b200. not sure about needs, but full duplex seems important for certain things.

>>60751723
>just bought one of those and looking forward to examining signals around my home. probably going to invest in a couple more so i can do signal triangulation.
>>>60751622 (You)
>what's the learning curve like for gnu radio?
>i was debating which one of the transceiver sdrs to get and it's down to hackrf, limesdr, bladerf and usrp b200. not sure about needs, but full duplex seems important for certain things.

Great!, Both blade and lime have limemicro chips. I've been working with Xilinx Sysgen for SDR, also with SystemC but GNU Radio is much more easy due the graphical building blocks, you'll feel very comfortable with it and I am pretty sure you will be doing good shit very fast.
LimeSDR have a big community, I think the same for Blade. That's one of the more important things.

>>60751479
give me a use-case for SDR. what the heck can I do with it?

I saw one guy on YT pull down weather maps from a russian satellite that was orbiting the earth. is that all?

Bought one a few weeks ago. Got the drivers installed on linux only to find out that the only SDR software that works is some autism tier GNU shit that you basically have to write pages of scripts for to make it do anything. The other popular linux SDR software is not compatible with the most recent two versions of Ubuntu.

>>60751967
or, as I've recently taken to calling it, GNU plus autism.

>>60751935
make your own LTE/3G basestation.

Basically a home made stingray.

>>60752038
>make your own LTE/3G basestation.
You do realize you could just buy a fetomocell for a fraction of the cost

>>60752003
Better to stick with GNU/autism if you are not willing to pay the money to have NI shit doing the work. Anyway SDR is a Jewish market (look for the price of NI devices or even Nutaq).

I remember seeing some guy who made a hardware RNG from it by tuning in to white noise.

>>60752057

can it do what a stingray can tho?

>>60752038
Got any good tutorials/guides to do this?

>>60752080
in about a 10m radius, while a BladeRF will hit a 150 meter radius.

>>60752057
>fetomocell
Which femtocell did you have in mind? I've never seen them under $100. And an SDR stick is like 10 bucks.

>>60752089
https://evilsocket.net/2016/03/31/how-to-build-your-own-rogue-gsm-bts-for-fun-and-profit/

>>60752109
thanks! looks like a great thing to learn. useful for just a general data gathering experiment.

>>60752105
>And an SDR stick is like 10 bucks.
Those are only the ones based on RTL tv tuners and dont transmit. As with everything you get what you pay for

>>60752133
ah, you're right. they're like half-duplex.
anyway, have you ever fucked around with a femtocell? I'm not sure which of them is well supported under linux etc.

>>60752158
>they're like half-duplex.
Its not half duplex. Do you even know what half duplex is? Obviously not. IT CANT TRANSMIT, HOW THE FUCK CAN IT BE HALF DUPLEX IF IT CANT TRANSMIT.

>>60751935

passive radar for detecting drones :D

>>60752203
kek'd. it will be useful in few year's time tho.

>tfw it turns out your single core CPU is actually decent enough for SDR
Now if only I could get this fucking serial driver to install I'd be set

>>60751479
Can I use a Wifi YAGI antenna on a RTLSDR? or do I need to make a pots and pans one.

>>60753030
You should get a different antenna, a Wi-Fi antenna's going to be either 2.4GHz or 5GHz and RTLSDR receivers cap at 2.2GHz

>>60752234

It's useful right now. Do you know what's flying over your home?

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>>60751723
>signal triangulation
This topic interests me. What front ends do you plan on using?

I see RTl-SDRs have been used though there is a lot of work to continuously re-sync the units to maintain phase coherence.

Best solution would probably be a unit with 4 ADCs and a goniometer implemented in an FPGA, I guess. Any suggestions on what is out there?

http://websdr.ewi.utwente.nl:8901/

Huge resource here: http://www.rtl-sdr.com/

>>60752203
how the fuck does that work?

>>60757221
You need a high powered transmitter. In this case he could use a nearby radiostation.
If the signal from a radiostation hits a drone, it will produce an signal that is slightly out of phase.
From that you could somewhat accurately deduce where the drone is.

Better would be to have 2 SDR using 2 different radiostations to have better accuracy

>>60757221
Look up passive radar.

Simple explanation: use a broadcasting station/base station/existing radar/GPS satellites/etc or anything that emits a signal.

Use 2 receivers:
one to listen to the direct signal from the emitter you are using, and
one to listen to a reflected signal from anywhere

Preferably listen for reflections from anywhere except from that direct line (to avoid saturation)
Preferably listen to doppler sifted signals only

Use a correlator to determine time offset between received and reflected signal. This gives you a hyperbolic solution.
Use a doppler analyser to determine radial velocity.

Then use multiple transmitters or multiple receivers to resulve the hyperbolic ambiguities.

Then use a tracker, better use a Kalman filter, to make sure the shifts match the doppler data. Offsets between real speed and doppler speed is the engine signature,

Probably sounds bloggy and complicated but really isn't. A dude in Finland demonstrated this a few years ago using RTL-SDR which has only 8 bit resolution.

Upgrade:
- use high precision receivers, at least 12 bits, better with 16 bits
- use bands from HF to SHF
- use multiple antennas in sectors
- use multiple polarisations

In the near-ish future probably most co-location base stations will be provided with a military box the size of a suitcase to do this and feed readings into a fibre connected centrakl correlator.

The reason to resist this is that the F-35 will be plainly visible this way. It was designed for monostatic radars only.

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>>60751935
When I'm in a city, where HF reception is impossible, I just listen to the airband (plane chatter) and police/train/fire dept/taxi services, eventually hams.

But when I'm in the countryside I just hook up to my aerial+yagi combo and receive HF, like chinese or arabic radio despite being in europe.
I sometimes even get something on 8992k but rarely. Here's a pic of what I can get after sunset on HF.

>>60753030
>>60753841
it will work, but the performance won't be that good since 2.4GHz is waaay above the typical wavelenghts you tune with RTLSDR into. E4000 chipset can go to 2.2GHz with abyssmal perf, R820T2 goes to 1.7GHz, but has better filtering.

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I'm checking ebay for these SDR USB dongles. I notice these terms:

>RTL2832U+R820T2
>HE RTL2832U+FC0012
>RTL2832U+R820T2 Y8
>R820T2+8232

What do these component IDs mean? Which of them should I buy? They're all around the same price...

>>60758399
Name of demodulator and tuner chip. Get anyone but the second one, FC0012 has smaller range than R820T.

>>60758467
Thank you!

So I'm guessing RTL2832U+R820T2 is the best combo? Or some other choice maybe?

Also, any preference for a manufacturer or is this all the same?

>>60758522
>So I'm guessing RTL2832U+R820T2 is the best combo?
Yeah.
>Also, any preference for a manufacturer or is this all the same?
It's the same.
If you want to change the antenna you might want to get one with SMA port, but if you're new you probably shouldn't worry about that and you can always buy an adapter.

>>60758399
>ebay
Careful, there are many scams there with fake parts.

so since i dont see a amateur radio thread, does anyone want to share here what software they use on linux for ham radio? i got a baofeng and my technician license recently and was wondering what i could do on linux, i like the concept of a logger if it can show the data to me in an interesting way

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LimeSDR

>>60764357
>Cyclone FPGA
must be expensive as fuck.

how much?

>>60764418
$289

>>60764478
yeah, that's a lot. but it's a cadillac of SDR I guess.

>>60764298
There is a ham category for Debian.

I see many use Linrad.

>>60764610
why? what are you able to do with it?

>>60764845
It is a front end for a large selection of digital receivers. It is huge. Start here: http://www.sm5bsz.com/linuxdsp/usage/newco/newcomer.htm

>>60752164
RRRREEEEEEEE

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what about this one?
cheap + good performance?

picked up an el cheapo nooelec sdr off of ebay last year, still a cheaper model but it was one of the higher ppm accuracy models they sold and it's fairly well calibrated compared to another el cheapo baofeng

next on the shopping list is a downconverter and maybe an upconverter, but I was mostly interested in shortwave so a downconverter is higher priority

>>60752057

Yeah but that's a lot less fun.

>>60751479
Can you hack drive-through systems with SDR?
https://www.youtube.com/watch?v=KyOHgNK0v6E

>>60751479

I wish I had money to do anything.

I'm too poor to buy any equipment. The only thing I have is one of those cheap TV RTL-SDR receivers.

>>60768448
When I worked at McDonald's we'd take our headsets and go fuck with Taco Bell employees, who used the same frequency

Do I need a license for this shit? (US)

I'm just learning about this now and it sounds fun to mess around with.

>>60768523
So what do you do with it?

>>60768604
License only to broadcast, receiving is free.

Cracking encrypted bands is not.

>>60768620
Thanks

>>60768639
IANAL, and cracking encryption is technically free, just illegal.

>>60768532
That's fuckin rich, man.

>>60768604
you need a license for transmitting on ham bands. fortunately tech license exam is easy as it gets and allows all modes on 30MHz and up.