Lutetium-
Hack Chat Transcript, Part 4
09/18/2019 at 20:40 • 0 comments![]()
RF will never cease to baffle me...![]()
ah ok as for aerial i use a discone antenna buit from pipe fittings and stainless steel rods![]()
Put it on a service monitor/sepctrum analyzer and feed a noise source into one side while changing the length of the open coax and you'll see the notch frequency change![]()
RF will always be magic to me :)![]()
:)![]()
@Dan Maloney I think it's like optics too... there's some wave particle duality think going on. :-)![]()
What kind of bandwidth does a filter like that have?![]()
There is always more to learn and I love it![]()
It's amazing. I got the opportunity to get a basic look into it at university :)![]()
think = thing![]()
And I am glad to be able to practice RF![]()
and communications systems in general :D![]()
@Dan Maloney I'm honestly not too sure, it's not a lot but it's enough that we've used them in commercial situations before to notch out a nearby interfering frequency on our repeater input![]()
Well, I mean, a notch is a notch, right? Should be pretty tight, I'd think.![]()
Yeah it's tight I just don't recall the exact bandwidth![]()
Read like a good scenerio to demonstrate in a video and/or write-up.![]()
it'll notch out a 25khz wide FM signal so I'd say at least 30khz![]()
Mathematically it's just the one frequency![]()
I should measure it some time![]()
Maybe can incorporate into the RTL-SDR way cost effective toolkit as a way to measure? Maybe compare with a better performing device to see capabilities?![]()
@James Finch you can use a noise source, RTL and an RF bridge![]()
Planning to do a video on that too![]()
@Signals Everywhere/KR0SIV - If I can put my $0.02 in and request a video on what you can do with an SDR and a digital scope to troubleshoot and design filters, etc. I think that's what you were mentioning before, but just wanted to plug for that. I'd find that super-useful![]()
https://www.rtl-sdr.com/tuning-an-hf-antenna-with-an-airspy-swr-bridge-and-noise-source/
Tuning an HF Antenna with an Airspy, SWR-Bridge and Noise Source
Over on his blog Anders J. Ørts has created a good writeup showing how he used the combination of an Airspy SDR with SpyVerter upconverter, SWR-Bridge and a noise source to tune his HF dipole for the 40 meter and 20 meter bands.
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Oops - missed @James Finch while I was typing. Same thing basically![]()
@Dan Maloney for sure, I want to do one filters and such, I may not have the work space to build a filter right now but I can take a ready-made cavity filter and tune that to show how the tools work![]()
Sounds awesome!![]()
It's crazy how much you can do with SDR these days![]()
Yeah... the Airspy HF+ with Spyverter looks good (maybe better in some freq ranges) compared to the SDRplay RSP1 and SV1AFN DC-55MHz upconverter.![]()
Heh I feel like I'm going crazy sometimes, I honestly have more than 50 ideas I could rattle off right now for videos I want to do (and have parts to do most of them) it's just a lack of time that keeps them back sometimes![]()
@Dan Maloney We need the redundancy... it's like a survey without the website.![]()
@James Finch Suposedly the RSP1 has true DB measurement which would be extra useful![]()
I still need to test mine out. Wound up working on outside projects.![]()
Wondering how the Spectrum Analyzer application performs also. The noise floor is great on those systems too.![]()
The analyzer software is hit/miss sometimes![]()
@James Finch - Basically I'm too cheap to buy a legit spectrum analyzer but I still want the capability![]()
There is one for the RTL that does 'okay' but I prefer the SpectrumSpy software![]()
I'll be using an AirSpy for my videos on filters/antenna tunning just because the software available is better![]()
@Dan Maloney Welcome to my life lol :)![]()
SpectrumSpy... I'll have to read into that. Is that what comes with the AirSpy?![]()
Thank you @Signals Everywhere/KR0SIV this was all very interesting and I can't wait to get home and continue playing with my RTL SDR:) But for now I have to go. Bye![]()
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I was lucky enough to get one of these though![]()
@James Finch yes it comes with the SDR# software/airspy![]()
Yeah... @Dan Maloney I was all over the web find ways to hack the FFT option to use on the TDS-520 and TDS series of oscilloscopes.![]()
https://www.rtl-sdr.com/spektrum-new-rtl-sdr-spectrum-analyzer-software/
Spektrum: New RTL-SDR Spectrum Analyzer Software
Recently a reader of RTL-SDR.com, Pavel wrote in to let us know about a new program called 'Spektrum' which he has written. Spektrum runs on Windows and Linux and turns an RTL-SDR dongle into a spectrum analyzer in a similar way to rtl_power GUI front ends and RTLSDR Scanner.
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The RFExplorer and RTL-SDR wasn't cutting it at the time. I could only do so much with microphones and Spectrum Lab and am still planning to invest in a better microphone.![]()
That's what could be used with the RTL![]()
It works but finiky![]()
Spektrum is handy... that's what I've used with the RTL-SDR.![]()
Not a bad application by any means but I'll probably still use spectrumspy over it given the choice![]()
I use it in this video where I was playing with a cheap ADE passive mixer ![]()
a HackRF & qspectrumanalyser is a nice option too. i was recently using it with a near-field probe set for some EMC pre-compliance work![]()
I didn't even realize SpectrumSpy is bundled with the somewhere in 2016 and later SDR# downloads:https://www.rtl-sdr.com/spectrum-spy-new-spectrum-analyzer-software-for-the-airspy/
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@Mike Walters VERY true! Wow how did I forget that one, it was the first thing I used![]()
iirc @James Finch it's also bunled with adsb software or at least used to be![]()
Does qspectrumanalyzer work with RTL-SDR's also?Here is a reference for the record: https://www.rtl-sdr.com/tag/qspectrumanalyzer/
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There is one dedicated for the HackRF too that works alright, it sometimes causes the HackRF to lock up on re-tune but you just re-plug it and it's fine https://github.com/pavsa/hackrf-spectrum-analyzer![]()
[Arsenijs] will have to try that one again - IIRC last time I tried that spectrum analyzer, it just segfaulted on me all the time.![]()
yeah, qspectrumanalyser works with RTL-SDR too. the nice thing about using it with HackRF is the tuning speed - it sweeps at ~8GHz/s![]()
^![]()
50mhz - 6GHz iirc and it scanned like no tomorrow![]()
wow, that sounds amazingly fast!![]()
I used HackRF spectrum analyzer to find my cell phone signal ![]()
Too much bandwidth can be a henderance sometimes but other times... it's exactly what you need to find something odd over a swath of bandwidth![]()
for this ability alone I'll always have a HackRF -
Hack Chat Transcript, Part 3
09/18/2019 at 20:07 • 0 comments![]()
Hiya!![]()
Way more complex when getting into the microwave range. Just watched a Keysight presentation noting how every section of a circuit in a system has to be studied to understand the affect... where I perceive is like an antenna basically so not to cause reflections, impedance mismatches, losses, etc.![]()
Speaking of filters the next one I need is going to be for broadcast AM, I need to get into VLF soon![]()
@James Finch very true, as you go up in frequency even the PCB material can affect the signal/circuit![]()
Well, every part of a RF transmission system has to be matched to achieve optimal performance![]()
@Signals Everywhere/KR0SIV any thoughts about Software Defined Antennas (for hobby use)?![]()
and yeah, it can get tedious quick![]()
@Max-Felix Müller What do you mean software defined antennas?![]()
@Signals Everywhere/KR0SIV Totally, the demonstration was just a via causing the losses around 20GHz.![]()
microwave is really finicky :P![]()
@Max-Felix Müller or I suppose you're asking what antennas to use with your SDR?![]()
@Signals Everywhere/KR0SIV antennas that can be tuned by software to have specific directionallity and/or use different frequencies![]()
A lot of it is still magic to me xD![]()
like https://en.wikipedia.org/wiki/Plasma_antenna ?![]()
or more beamforming?![]()
Generally you want a tuned antenna if you can, 2m antenna for 2m, L band antenna for L band etc..However for general reception you could go with a discone antenna
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Or phased-array like radar.![]()
The antenna is the MOST important part of your radio system, doesn't matter if the radio cost $10M if your antenna is crap it's not going to work![]()
I am picking up Spanish AM/FM? stations up around 500 MHz on the RTL_SDR V3? Any idea how it gets mixed in. My Spanish is not good enough to tell which station. In terms of algorithms, it would be nice to have standard ways to identify strong interference sources, frequency drifts, sferics (lightning), and identify stations location and information automatically.![]()
beamforming is already done by an array of antennas; if you can vary the phases going to the antenna elements; you can "steer" the array electrically![]()
I use a discone on my FlightAware SDR and I find it to be a poor performer. Could be the long and lossy feedline, to be fair.![]()
@RichardCollins It could ben a strong harmonic mixing or intermodulating![]()
I'd tune around to see if you can find which station it is in the broadcast band![]()
There must be an FM nearby--very nearby--to get images at 500 MHz.![]()
then look it up with the FCC to get the location![]()
and power![]()
While talking antenna questions, I just typed this one up, n00b question incoming:Great chat, thanks for it. Quick question. Wondering what the term is for what I ran in to this past winter.
I had (still use) a cheap 800mhz Yagi antenna and at this point I had it distributed to many (6 or 7?) RTL-SDR v3's all monitoring the same (800mhz) P25p1 system via UniTrunker/DSD. I'm sure this distrib/amp thing was not the best choice but it worked: https://www.amazon.com/gp/product/B002M1EPL0 And this sytem worked for a good long while but sucked in that it was LSM system with UniT and bad quality.
Well this past winter I stood up a TrunkRecorder/TrunkPlayer linux system and moved some of those SDRs to the new linux system. Still monitoring the same system/freqs, no problems at all. Loved the new quality, TR/TP very much wipes the floor with the old system.
The problem occured when I took some of those same SDRs fed from the same antenna and used them to monitor a 700mhz system. Once I did that it started killing the SDRs that had been rock solid on the orig 800mhz system.
Took me a few days to realize the root cause, but now I'm fine. But I'm curious what that was. I imagine it is some Radio Basics 101 thing, but if you or anyone could just give a search term I'd super appreciate it.
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Right @Joyce That's probably going to be the limiting factor in dirt cheap really wide frequency range and bandwidth COTS hackable systems for now, until a high volume produced system that can be hacked openly will bring the price point down or is cost effective to begin with. I'm wondering about the 5G chips and evaluation boards... as much as I am nervous about not being aware enough of the lower latency, back door and interception concerns since from what I understand is developed outside the U.S.![]()
I had been talking about that for the past few days with a few friends![]()
The FCC site has a geographical search; if you know where you are, search for the 30 km radius around you. I use it to look for interesting signals.![]()
To me at least, the mobile phone and its network is like a blackbox![]()
@Joyce Right! Once you learn the tricks... it's "eye" opening. Like they even use eye diagrams that literally open with improved performance characteristics.![]()
It's hard to understand, and a lot of details are hidden and/or behind NDAs![]()
@Dan sounds to me like your antenna wasn't matched SDRs generally have a 50ohm or in the case of cheap eBay units a 75ohm impedance, if you don't match these you'll end up with signal losses and when transitting it's even possible to damange the radio![]()
Try for example, figuring out how the baseband processor in your phone works![]()
I know a French guy on Twitter who works for La SNCF, the railroad. They use a form of GSM for their comms. He's in the telecom dept.![]()
I will use those terms to look. This must happen all the time. But the SDR software does not have that neatly package. Likewise SDR radar, meteor tracking, lightning mapping, radio astronomy, direction finding and many other applications of SDRS and SDR arrays.I am mainly worklng with problems that require thousands of detectors globally. Steering those required high sampling rates and 3d reception. (Three axis and tensor sensors)
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try getting even the datasheet, the registers details![]()
etc![]()
Not matched antennas and receivers will lead to reflection which is likely to damage your sender if not protected![]()
OK, here we are at an hour into the Chat, which is where we usually let the host off the hook so he or she can get back to work. If @Signals Everywhere/KR0SIV wants to hang around and keep answering questions, he's more than welcome to. I'll keep monitoring the Chat to make sure I capture all this great stuff for the transcript.@Signals Everywhere/KR0SIV - Thank you so much for hosting today. Your enthusiasm is infectious, really has me worked up to improve my SDR game.
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Speaking of direction finding, the KerberoSDR is amazing when paired with the android app for it![]()
@Joyce I agree with you about datasheets and registers. LOL!![]()
Btw, if you join the Discord, we can chat about this and other related topics more ;)![]()
Here is the FCC geosearch:![]()
Thanks !![]()
https://wireless2.fcc.gov/UlsApp/UlsSearch/searchGeographic.jsp
License Search - Geographic Search
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Thanks @Dan Maloney yeah I'll hang around for a little bit more, if anyone want's to hook up with us down the road after the hack chat we're also on discord https://signalseverywhere.com/discord![]()
Yup that FCC Geosearch can do wonders![]()
I've a SDR project of my own that I am still working on![]()
just a few miles up the road I have WKKY a several KW FM station at 104.7 mhz![]()
even with a BFM filter a little gets in![]()
and I see it all the way up into the L band![]()
Yeah, the KerberosSDR looks nice... glad to see that application.![]()
It's a little late on schedule though, thanks to daily work commitments xD![]()
Okay good stuff. Very possible mismatched ohms. I joined the Discord a bit ago, might f/u there if that's ok. It just seems the issue started when I started using the same Yagi to monitor both a 800mhz and 700mhz system with diff radios. Is that a known basic radio thing, you can't use an antenna to monitor that big of diff freqs at same time? I![]()
As in: 2 radios, one antenna?![]()
yes via that splitter I linked,... more than 2![]()
all RX only![]()
Then you'll effectively halve the signal power from the antenna![]()
Yup each time you spit it you'll lose 3db if I'm not mistaken ie: half![]()
If one receiver is mismatched its reflections will also affect the other one, right?![]()
Think about how the signal is induced into the antenna, and how the current has to split into 2 paths![]()
@Max-Felix Müller et.al. I just commented to Andriess Spies wondering about the most cost effective way to tune sections of the TX/RX system. ![]()
yeah,..vaguely aware of that.... I think its less db loss and more harmonics and the stuff you're talking about now![]()
I'll chew it over some more,... thanks for the info@James Finch interesting, thanks
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Using an RTL-SDR or other SDR and noise generator. Here is another link with references in the comments also where @Signals Everywhere/KR0SIV was my hero in exposing signals more on a way cost effective budget (specifically the pan adapter and discrimination tap). https://hackaday.com/2019/07/31/rtl-sdr-seven-years-later/
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I'll check it our later but I made a note so I won't forget :)![]()
@Max-Felix Müller I'm wondering if he or someone else will make an updated video for tuning components or sections of the system.![]()
@James Finch @Max-Felix Müller I am absolutely going to do some videos regarding tuning antennas and filters using SDR and the NanoVNA![]()
Just need to sit down and record them![]()
Amazing what old equipment can be hacked into more process able systems. Like... who'd a though you can make an SDR out of an Oscilloscope.![]()
@James Finch They actually have kits for making low bandwidth soundcard SDRs![]()
@Signals Everywhere/KR0SIV cool. Did you already post a link to your channel and I missed it?![]()
It's an interesting idea, and heck, even your sound card can be used as part of a SDR RX/TX chain![]()
WB5RVZ Software Defined Radio Homepage
This site is devoted to the area of Software Defined Radio (SDR), more specifically, the "Softrock" series of technology sampler kits and the GenesisRadio.Com SDR transceiver. These kits are for working amateur radio HF receivers and transceivers. These kits have provided an economical, relatively risk-free, and exciting entry into the SDR tent.
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just need the proper analog frontend![]()
@Signals Everywhere/KR0SIV - +1 on those videos, can't wait. Was actually pricing out a NanoVNA today - about to take the plunge.![]()
Or older systems are way cost effective used and can have a pan adapter and/or discrimination tap ran out to run into an SDR, video or Audio input for way more processing.![]()
@Max-Felix Müller https://youtube.com/signalseverywhere![]()
@Joyce for sure.![]()
I was going to mention that, @Signals Everywhere/KR0SIV![]()
A somewhat shallow plunge at only $80, but still...![]()
I think I only spent $38 on mine, did the price go up?![]()
$45 for this one https://www.ebay.com/itm/NanoVNA-Vector-Network-Analyzer-HF-VHF-UHF-Antenna-2-8-TFT-Screen-50-900MHz-USA/254342318350?hash=item3b37fbc90e:g:gRwAAOSwgR5dZO-L![]()
@Signals Everywhere/KR0SIV Looking forward to, that would be awesome. I was amazed what LMR400 and being careful with lengths of the feedline and placement of the RTL-SDR did to the discones performance.![]()
I saw low-rated knock-offs on Amazon for about $50. Higher rated ones were $80![]()
for sure, everything affects your signal![]()
You can actually make notch filters out of LMR400 @James Finch![]()
hi guys![]()
and also matching stubs! :D![]()
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out of coax![]()
i see you are talking about sdr![]()
@Signals Everywhere/KR0SIV Nice!![]()
Yes, @jmcservv The SDR HackChat was about an hour ago but I'm still hanging around for a bit![]()
Does the 1/4 wave stub just dead-end in an open circuit?![]()
@Dan Maloney Yup, it's just an open length of feedline![]()
The 1/4 wavelength filter has the benefit of dampening also harmonics of that frequencyHack Chat Transcript, Part 2 09/18/2019 at 20:05 • 0 comments
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@RichardCollins I'm playing with Viasat Surfbeam 2 modems and their TRIA's (Outdoor units) that supports Input (RX) Frequency 18.3 to 20.2 GHzOutput (TX) Frequency 28.1 to 30.0 GHz. I'm getting them on various none-ebay portals for really cheap. Drop me DM and I will share with you my wiki. Or join Signals Everywhere discord where I'm pulling out my RF knowledge.
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[Arsenijs] Discord? Got an invite link?![]()
@Chris Capobianco You don't need an LNB, that range is covered by most RTLs, I'd recommend a helix antenna on a dish![]()
@IRC https://signalseverywhere.com/discord![]()
Absolutely agree. But that dog won't hunt around here - people here have a bit of a blindspot when it comes to law enforcement. Even RadioReference.com will ban you now if you complain about encryption. Kinda nutty.![]()
yeah encryption is a very hot button topic![]()
I hear there are a few groups planning on breaking it and presenting at Defcon, we'll see if they manage but if so it'll change the landscape![]()
Totally need to monitor the monitors for sure. Let's see... representative government is sworn with oaths and like President Lincoln stated... for the people and by the people.![]()
@BSA Secure Thanks I will contact you after this![]()
More than nutty, seems like a blatant compounding and concealing.![]()
This is probably a dumb question, but are these chats logged? Can I just load this URL later and grab all the chats from this page?![]()
@Sheridan-Tech I believe @dan![]()
there will be a transcript posted after![]()
welp that didnt work :p![]()
Yes it'll have a transcript![]()
@Signals Everywhere/KR0SIV Thanks, Much appreciated!![]()
@Sheridan-Tech - I post transcripts right after the chat.![]()
Ok. At this link? Or found elsewhere?![]()
I'll post a link when it's live.![]()
Just keep in mind, that by observing encrypted traffic you can know of stream is voice transmission , drone-high-bandwidth video footage or small telemetry. Its like listening train that is passing by - you can know if its empty or is full of heavy elephants (even with oracle padding)![]()
Hack Chat Transcript, Part 1 | Details | Hackaday.io
TBD
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may be not know but rather assume![]()
My opinion is we need to hack relevant U.S. Jurisdiction (State, District, Tribe, Territorial and Nation) Constitutional and Statutory Law into the Public School's from kindergarten on up ASAP. Post 1960's change in being able to be admitted into the bar with a J.D. was a root cause from my observations.![]()
thank you![]()
Very good point @BSA Secure that's true of most digital modulations.Once you have listened for a while you get an ear for things and you can quickly determin what type of modulation it is and often if it contains data or not
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Looking back at transmit capable SDRs I'm pretty excited about DVB-S for digital amateur television![]()
@Signals Everywhere/KR0SIV I started listening to some FM stations using an RTL SDR but I'm not sure really where to go from there...![]()
Prior to the 1960's I think most had a basic Ten Commandment fundamentals to counter claim and defend Rights... and like Yale was the last to admit into the bar with a Bachelors of Law.![]()
Any recommendations for a software/security person? IOT is the punching bag. If I get an SDR I want to try metasploit's hardware bridge![]()
There is a lot of good software support for them now and you can transmit low bandwidth digital tv with a PlutoSDR or limeSDR.. heck even a Raspi on it's own can do it![]()
When using my RTL-SDR on ham frequencies I hear some unusual signals. Does anyone know where I can find a list or page with samples that I can compare to, to help me identify what I'm hearing? For instance if it is just interference, the signal needs to be attenuated, some type of side band, digitial, or it is encrypted.![]()
OK... back to finding links for simplifying installs...![]()
@James Finch legal stuff is different topic - I'm from EU and here listening on ADS-B traffic is illegal. There are laws that generally forbid you to decrypt eg P25 traffic. Putting OpenBTS is illegal in US and EU and people are doing this. Just dont f-ck with the legit service![]()
There are a number of algorithms to pull the human signal from the radio data. Like "AM" "FM" "USB" "LSB" and so forth. It is scattered in the software, but perhaps should be set aside to investigate and test as a separate discipline.So "Demodulation" algorithm suite that can be plugged into any SDR software?
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@Max-Felix Müller You'll want to install virtual audio cables and try to decode some stuff. there are decoders for almost anything you run into![]()
@Maave You'll be interested in things like RTL443 https://github.com/merbanan/rtl_433 and URH https://github.com/jopohl/urh![]()
https://www.sigidwiki.com/wiki/Signal_Identification_Guide for visual references. I've not seen a compile app to perform a pattern recognition processing and output ranking of most likely signal yet.![]()
These are great for discovering telemetry data and tearing apart modulation types![]()
sweet, thanks![]()
Thank you![]()
Just wrote up a hack that used rtl_433...![]()
Nice! @Dan Maloney Not sure if I saw it or not, can you post the link?![]()
I still need to do a video on it![]()
@BSA Secure No kidding... still Pro Se defense from my perspective unless Deliverance style juris is the best defense... and even then get's them ew ew'ing differently.![]()
You noted a great pro se defense tactic/strategy.![]()
Cheap Sensors And An SDR Monitor Conditions In This Filament Drying Farm
We don't know where [Scott M. Baker] calls home, but it must be a pretty humid place indeed. After all, he has invested quite a bit in fancy vacuum storage containers to keep his 3D-printer filament dry, with the result being this sensor-laden filament drying farm.
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Forgot which one it was. He ended up using 315 MHz for his sensors but rtl_433 still worked for that band.![]()
You've gotta love how cheap these little modules are![]()
Awesome that will be helpful. Sorry for inundating everyone with questions. I am just new to this particular portion of wireles![]()
I've been considering reversing a 315 mhz RC car board so I can use an SDR to control an RC car![]()
@Sheridan-Tech That's what this is all about! Fire away, I'm here to answer questions the best I can![]()
:)![]()
I often see "Donate" and "Support" and "patreon" on software and hardware sites in this SDR community. But I am NOT going to put my credit card info on a flybynight site. Is there any thought to having better standards for things like fund raising, crowd funding, individual support? I see lots of things I want to enourage, but there is not a "safe" way to do that. Thoughts? Suggestions?![]()
@RichardCollins I'm still working my way back in Reddit posts since searches aren't coming up with what I'm looking for. I did find these references to consider for procedures development in GRC:https://wiki.gnuradio.org/index.php/Guided_Tutorial_GRC (GRC Tutorial Wiki)
https://www.instructables.com/id/RTL-SDR-FM-radio-receiver-with-GNU-Radio-Companion/ (Instructable for FM Radio)
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@RichardCollins it all depends on what you consider safe I suppose. My donate button my website uses PayPal which I trust to do right by consumers and Patreon has never done me wrong. Some accept cryptocurrency but that's not something I generally play with.![]()
I'm curious if some day with ADCs > 1Gsps, we might eventually see direct sampling SDRs, with the ability to captures masses of bandwidth instantaneously?![]()
@anfractuosity I could see that, the problem then would be how to get that data onto your computer, USB probably wouldn't be the interface of choice at that point but rather ethernet which would drive up cost![]()
oh yeah heh, might need pcie![]()
Seems like the extra cost could be worth it though![]()
Always, the issue is not about acquisition![]()
@anfractuosity they already exist, they're just in "call for a quote" price territory![]()
I just bought a 5.85 GHz drone camera receiver just look at. VERY nice looking hardware, but I have not a clue how to get the signal from it into my SDRs. I am a mathematical statistician not a digital engineer. Is there any way for ALL these hints and clues and methods to be kept where it accessible to everyone - all the time?Richard Collins, The Internet Foundation
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@anfractuosity I guess it's not just the ADC but also further down the line. FPGAs, USB, your CPU which has to handle all those samples at some point in time...![]()
but how do you get the data into your system![]()
Being able to capture lots of bandwidth is nice but I still prefer to use the least I can, it's part of why I use an RTL-SDR when I have an Airspy R2 sitting there. They both work well but the more bandwidth you're looking at the more likely you'll lose your signal in all that nosie![]()
@RichardCollins et.al. Found the reference for the Windows 10 GRC install:https://www.reddit.com/r/GNURadio/comments/ao79a5/grc_on_windows_7_pro/
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noise*![]()
at such high speed![]()
(also hiiii! :D )![]()
The ethernet technology is much more mature and less costly than USB. Steep learning curve but worth it.![]()
@RichardCollins Not many SDRs go that high but the PlutoSDR can as well as the HackRF![]()
https://www.pervices.com/shop/ - 1GHz BW for only $73k :p![]()
You can technically use an RX5808 as a down converter too![]()
haha cheers @Mike Walters , bit out of my price range![]()
to me it's less about bandwidth and more about frequency range![]()
ofc with the ranges most SDRs cover today you can down convert almost anything else you might want/need![]()
Sampling rate also.![]()
What would be nice is if I could find a 4 or 5 ghz oscillator and build a down converter for 5ghz![]()
Seems Ethernet when I looked at last for being most cost effective. Fiber optic interfaces would be awesome, though cost more.![]()
Sample rates are important but generally 2.8msps is plenty imo![]()
I'm sure you can, just don't know the cost :P![]()
I have SDRs that'll do 10-20 and even 30+ msps but limited to a USB 2.0 interface![]()
Generally the most I'll use is 20msps since I can look at an entire trunking system at once![]()
I guess I'm thinking in more a real or near real time wide frequency range... and to obtain a more accurate widest frequency range.![]()
but with two RTLs I can track it all the same so it's nice to have but my focus is on rx sensitivity![]()
@Signals Everywhere/KR0SIV You are talking about the difference between looking at a source at a particular center frequency, and looking over a range of frequencies. I am setting up to scan the full range of each of my SDRs continously for decades. It is to map the electromagnetic "weather" of the earth at fine detail. It requires global networks of SDRs continuously recording, analyzing, comparing, calibrating and working together. We are just at the very beginnings.![]()
interesting concept![]()
Like I said it's all about individual needs, for something like that I could see where that would be beneficial![]()
You mentioned earlier about using a filter, when transmitting, can you get a little box, that you can easily change the filter properties, for different bandwidths/ frequencies?![]()
Yeah, love to see a writeup, even if you're still just planning![]()
for me and many who are just playing around generally it's about having the capability tune to whatever freq they want and decode or manipulate it... or it's about tx capability![]()
you'd rather do that in DSP @anfractuosity![]()
@anfractuosity not that I've seen, those I've seen people build them for HF![]()
which is what makes SDR so powerful :P![]()
im referring to transmission though, to filter harmonics @Joyce![]()
oh haha![]()
Hi @Joyce !![]()
I am looking mainly at the microHertz to kiloHertz range. The signals are mixed and have many human interferences. So mapping the earth's electromagnetic field is just so I can tease out the low frequency interference with theHack Chat Transcript, Part 1
09/18/2019 at 19:35 • 0 comments![]()
OK, everyone, it's noon here in the Pacific time zone, so let's get started. Today we have @Signals Everywhere/KR0SIV to talk about software-defined radio, which I can't believe we've never done a Hack Chat about.@Signals Everywhere/KR0SIV - Welcome! Can you kick us off with a little about yourself and how you discovered SDR?
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Sure thing @Dan Maloney So my name is Harold Giddings although most online know me as Corrosive or my amateur callsign KR0SIV
I originally got involved with SDR when the RTL drivers were originally modified from old TV Tuners to an SDR platform.
This was years ago when I was still active on IRC and once I saw these things in action. I was officially addicted
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I'm currently employed as a commercial radio technician and so thankfully I get to have radio fun most days even when I'm not playing with an SDR (which I still find excuses to use at work)![]()
What SDRs are you using now, and what software do you use?![]()
Software Defined Radio is really what got me back into radio. I take my amateur exam shortly after getting into SDR.It was like opening an entirely new world being able to look at the radio spectrum via the waterfall rather than scanning individual channels.
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[Arsenijs] should work now (ignore this message)![]()
@RichardCollins Currently my primary daily drive is still the RTL-SDRv3 from the https://rtl-sdr.com blog however I have a large plethora of SDRs these days. My favorite SDR client software would have to be SDR# however, I make often use of CubicSDR and SDRConsole as well as when transmitting... SDRAngel![]()
Do you have particular "targets" or frequency ranges, or just browsing generally?![]()
My primary SDR for transmit has to be the PlutoSDR because it was affordable, has a good housing on it and is of course full duplex![]()
Totally awesome the visual representations of what you first hear on the radio (or maybe other sensor stimuli too)... then see in other ways to identify, qualify and quantify.![]()
Frequency ranges really depend on what I'm doing. Generally I like to play around in the SW/HF bands as well as looking for digital stuff in the commercial end of the 440 MHz range as well as 800-1090 for P25/trunking/ and ADS-B![]()
I can't wait until lab-grade spectrum analyzers are as cheap as SDR dongles ;)![]()
Satcom is also a big thing of mine so I'll often be playing in the L-Band around 1.5ghz![]()
Have you ever come across unencrypted 'sensitive' data? If so, how did you handle it?![]()
for satcomms do you need a dish, also what kind of data do you pick up from them?![]()
The PlutoSDR hack looks nice, thanks for sharing that.![]()
I'm keeping my setup simple and cheap by using RTL-SDR's... until I've decided to extend my knowledge and play around wide bandwidth Ka-Band satellite links that and bought LimeSDR (after getting WAF .. Wife Approval Factor. Now .. everyday I'm learning from Signals Everywhere community so I can dive deeper in RF "Hacking".![]()
@Joshua Conway I do sometimes come acrossed sensitive data.. The key is simply not sharing it, if I do a video that contains such data I'll blur it out (such as my decoding of a pager signal)![]()
The SDRs are improving, but they still have issues with comparison between different actual devices. I have two SDR V3s and they give totally different results on the same antenna.![]()
@anfractuosity This depends on the satellite you are looking at, sometimes I'll be in L-Band looking at inmarsat or iridium, a dish can be helpful but a tuned panel antenna works fine. There are also UHF band satellites that have analog voice on them![]()
Generally a dish is needed for Ku band / C band and other SHF![]()
@BSA Secure you can still do a lot with a typical RTL based SDR![]()
@Seth I recently found another oscilloscope plugin for SDR# that I haven't verified/tried yet that isn't the one from IN3IEX: http://www.amfone.net/Amforum/index.php?topic=34858
https://qsl.net/e/ea1kr//sdr/rtlsdr/
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for example looking at Ku band![]()
You can use the LNB as a down converter, technically... that's what it is![]()
You just need an external bias-t to push voltage to it for power![]()
@Joshua Conway, whenever you will take a look on something, you will see that you can find sensitive data. For example, military traffic is encrypted so you cannot (and shouldn't) put your hands on - but still you can notice that protocols allows you to e.g. count how many participants are on the channel - it means that by monitoring traffic you can count how many military / police units are in the area.![]()
@Seth et.al. this reference to SDRSharper doing a Google search from a Twitter post to find the above links and will try when I get the time:![]()
@RichardCollins I'm curious what kind of differences you are seeing![]()
@Signals Everywhere/KR0SIV Do you have any experience with radio astronomy using SDRs?![]()
Thanks @James Finch ! I'll check that out!![]()
@Chris Capobianco I've not yet delved into radio astronomy yet although I know you can detect the Suns radiation with a typical Ku LNB, it's something I want to get into but am currently limited in places I can set up a dish![]()
cheers @Signals Everywhere/KR0SIV , the data from irdium/immarsat is digital then? what kind of software do you use to decode that data?![]()
@Signals Everywhere/KR0SIV Same here. Thanks for the information.![]()
Hello to everybody, Anybody here has experience on electric utility remote telemetry unit signal decoding on 450MHz with RTL-SDR?![]()
@Seth et.al. Right, very welcome. This was interesting finding also in that same search as I've been wondering and thinking can so, something I've wanted to try with my TDS-520 test bed frankenscope either directly or with a pan adapter in some way:https://www.rtl-sdr.com/gr-oscilloscope-using-an-oscilloscope-as-a-software-defined-radio/
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@anfractuosity Inmarsat is pretty straight forward, you can use USB in SDR# (or whatever) and pipe that audio using virtual audio cables into various applications for decoding. I have a video on this here: ![]()
cheers, will watch that!![]()
Iridium I generally don't recommend playing with as all the data contains are phone calls/text messages and other private information![]()
Although, there is software for this too![]()
ahh![]()
@Signals Everywhere/KR0SIV are there any decent low-cost amateur SDR rigs -- the equivalent of the low-cost QRP rigs available from a number of sources?![]()
Inmarsat contains all kinds of data, some public such as emergency events and weather![]()
some not so public like medical calls to aircraft![]()
but for those you need to compile a voice codec which is easier said than done (but doable)![]()
I will send you a private message with some images. Generally the gains and frequency responses are different for the same software settings. I ran a five hour comparison last night over a 200 kHz region with one peak. The shifts across all frequencies are close to the same, but the individual signals are quite different. Part is the problem of synchronizing and comparing signals from the two devices. No timestamps in any of the data. No quantitative measures in SDR#. Sliders with no numbers.![]()
@Seth et.al. Spektrum is about the best I've used as a spectrum/signal analyzer with an RTL-SDR and there is the HackRF and SDRPlay ones also I haven't tried yet. Amazing there are even protocol analyzer like apps too.![]()
@Curtis Franklin The only one's I've seen are the mcHF and it's clones![]()
@Chris Capobianco I'm working on re-purposing Ka-band household hardware to be re-purposed for radio astronony. By using 30euros hardware you can receive (RX) Frequency 18.3 to 20.2 GHz which is still valid for radio astronomy,![]()
Everyone, please add LINKs to mentions of specific software. These are HUGE internet topics. Narrow us down to a click. Thanks![]()
@RichardCollins Might be something that can be developed and validated in GRC?![]()
and you can you RTL-SDR as its downcoverts to 300MHz - 800MHz![]()
Yes, good idea. And keep in mind that there'll be a transcript available online after the Chat in case you want o refer to anything![]()
Here are some of those decoders for inmarsat http://www.tekmanoid.com/egc.shtml http://www.inmarsatdecoder.com/ https://bitbucket.org/scytalec/![]()
@Signals Everywhere/KR0SIV What's the least expensive SDR that could be built and deployed en masse?![]()
@farmboy this is a difficult question, it depends on what features it needs![]()
I generally say it's not about which SDR is best or the cheapest, it's about what SDR best fits what you want to do![]()
900 ISM, OOK / FSK. :)![]()
@James Finch I do not know what GRC is? Can you provide a link? Thanks Happy to look at it.![]()
Then you'd be fine with even the bottom of the barrel RTL on eBay honestly @farmboy but I'd still recommend at least the RTL-SDR v3![]()
GRC: https://wiki.gnuradio.org/index.php/GNURadioCompanionGreat Scott Gadgets GRC Tutorial: https://greatscottgadgets.com/sdr/
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@RichardCollins GRC is a format used by GNURadio https://www.gnuradio.org/![]()
What's the top of the barrel?![]()
@Signals Everywhere/KR0SIV Do you have a sort of checklist for what devices fit what needs?![]()
I do have a basic comparison chat that's still a WiP https://signalseverywhere.com/sdr-comparison-chart/![]()
Hello everyone :-)![]()
@Signals Everywhere/KR0SIV How do you transmit with a RTL-SDR? Are there other transmit/receive chipsets you would recommend? I am a Computer Engineer and have thought about prototyping my own.![]()
@Sheridan-Tech You don't "technically" transmit with an RTL-SDR, there have been some that have managed to modulate data using a leaky LO but for a real transmit capable SDR I'd recommend the PlutoSDR at around $130 it's the cheapest SDR based option![]()
@RichardCollins Your welcome, I'm trying to find some references I made on reddit and FB regarding the windows installation of GRC since can be a, what reminds me of a Java app programming and program installation nuances, pain.![]()
There are also those cheap VGA adapaters that could be used to transmit cheaper![]()
@Signals Everywhere/KR0SIV - Mind if I ask a little about your day job? What's new and exciting in public service radio these days? Everything is digital now I suppose.![]()
https://www.rtl-sdr.com/?s=vga
Search Results vga
Osmocom are some of the people behind the original discovery and development of the RTL-SDR (in particular Steve M), and today it looks like they have done it again by releasing exciting news of a way to turn a commodity $5 USB to VGA adapter into a TX-only capable SDR. They call their discovery 'osmo-fl2k', as the magic chip that makes it all happen is a Fresco Logic FL2000.
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What's your take on RPi 3 and Rpitx lib?![]()
@Sheridan-Tech https://github.com/softerhardware/Hermes-Lite2/wiki/Group-Buy![]()
@Sheridan-Tech What about RaspiTX ? You can transmit using FL2000 chip or raspberry pi .![]()
*Mind blown*![]()
@BSA Secure Can you provide a link to what you are doing? I tried to find you before to get specifics to try that but could not find enough info to reproduce what you did. I want to look up to 40 GHz, but downconverters for the 1-20 GHz seem to be available --- IF one can connect them to the SDR. It is not the money - it is the time to reproduce what someone else tried. Saving a few hundred dollars on hardware then spending three weeks to get it to working is false economics.![]()
@Dan Maloney Most things are digital, most of the time our commercial customers get DMR Capacity Plus and Linked Capacity plus. Most of our police departments are on the state MARCS IP system which is Phase 1 P25![]()
After adding filters (I'm bothering @Signals Everywhere/KR0SIV to prepare simple how to build filters)![]()
@Joshua Conway the RPITx library is great! I need to use it more, keeping in mind it's low power and very dirty... it's still great to learn and probably one of the cheapest methods to transmit![]()
Yes very correct @BSA Secure a filter should ALWAYS be used when transmitting anything that will go more than a couple feet![]()
Thank you all. I was looking forward to this chat since it was posted. Now I have quite a bit to go on.![]()
You don't want to cause interference![]()
@RichardCollins et.al. I first started with this crude reference that didn't cause me any issues. http://dewdetectionprojects.blogspot.com/2017/11/generic-procedure-for-installation-of.html
For Windows 10 I had issues... so wrote something up somewhere I guess like I was thinking on FB and Reddit...
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Yeah, not only digital but encrypted, or at least that's what I'm seeing. Used to avidly listen to local law enforcement on the state trunking system, but they encrypted everything last year. Bummer![]()
There is no encryption in use for the most part in our state, generally this is because of the high cost to encrypt but also to public backlash about the fact that we should be able to "monitor the monitors" if you will.![]()
@BSA Secure I was planning on the 1.4 GHz range for neutral hydrogen, is there a LNB for that range?![]()
I have a few RTL-SDRs set up at work and use it to monitor the system, it's funny because you can tell if someone i
RF will never cease to baffle me...
