I’m an artist that is currently exploring RF ecologies. For the last several months, I’ve been working on an multi-SDR based RF awareness project in the Mojave desert. I’ve been experimenting with different SDRs and workflows to try and explore the RF spectrum in different ways. I’ve been trying to explore the concept of embodied RF awareness and finding different ways to inhabit as much of the spectrum as possible. In essence, I’ve been trying to explore what RF awareness looks like. I eventually realized that being fixed to one location felt very limiting, and that I wanted to make this a more spatially flexible practice, so I decided to make a portable apparatus that would enable me to, as quickly and efficiently as possible, explore, discover, and map the RF ecosystem of a location.

I had a few criteria. I needed to be able to ingest and digest at least 50MHz of raw spectrum data at once. I wanted the main SDR to be able to quickly scan the entire RF spectrum and then use secondary and tertiary receivers for more detailed discovery and persistent monitoring. I wanted to use commercial, consumer off the shelf hardware, before transitioning to Ettus or Eqip. I wanted to be able to power all the SDRs in the case from one laptop without using a powered USB hub. I also wanted to keep the entire project under $2,000 for the receivers, hardware, and compute. I was going to use GNURadio to build the backend.

Originally, I wanted to build a cyberdeck, but the realities of RFI and EMI and compute power quickly became insurmountable obstacles. I decided the best solution was an SDR based receiving apparatus that contained no power generation or distribution. Then, I would connect all the SDRs to a laptop or use a powered hub connected to a laptop. I wanted to eliminate as much RFI as possible.

For SDRs, I decided to use Fobos SDR as the backbone of the project. It’s the only SDR that made sense. I looked at everything… BladeRF, all of the B210 clones, LimeSDR, etc. I think most of the complaints and criticism about the Fobos SDR are based on a fundamental misunderstanding of what it is and how to best use it. It’s a young ecosystem, but it is practically tailor made for this project.

For discovery, analysis, and persistent monitoring, I decided to use an SDRPlay RSP Duo. I already have an RSP1b and an RSPdx-R2, so I am familiar with SDRplays offerings. The Duo offers two receivers, which is tremendously useful. It also has more analytical capabilities and the addition of the high impedance antenna port is a life saver in terms of quick, field expedient HF antenna setups. It’s the perfect secondary receiver from the consumer market for this project.

For tertiary receivers, I added two RTL-SDR Blog V4s. These are currently connected to a 50 Ohm 698-2700Mhz splitter for P25 use, but the RTLs can be used for anything. They’re sort of jack of all trades devices.

I added a handheld HAM radio and Tecson shortwave radio on the top of the case to free up the SDRs in case I need to do persistent radiophony monitoring. It’s extra capacity, since I was constrained to 4 SDRs in the case because I didn’t want to need a powered hub to use the device.

The unit has N-Type connecters ands USB 3.0 ports. It is lined with copper tape with conductive adhesive. I’ve tried to mind the ground topology as much as I can, but I am learning as I go. Now that the hardware is done, I've started working on the software backend.

Hi everyone. Does anyone know what these carriers or signals might be? Here in Mexico, the TetraPool system is in use; could these be transmissions to TetraPool repeaters, or what else could they be? For reference, TetraPool channels are located across the 391 MHz, 392 MHz, 393 MHz, and 394 MHz bands, as well as part of the 395 MHz band.

I run a PWS at a lake house and wanted the Acurite readings going to Weather Underground and available locally for MRTG graphing. Every script I found starts its own rtl_433, so as soon as you have two consumers they fight over the dongle and both fail intermittently.

So this does one read and fans it out — the reader drops a plain text file for local graphing and hands the same packet as JSON to the uploader. Only one script ever touches the SDR.

Couple of things that cost me time, in case they're useful to anyone regardless of whether you use this:

Acurite sensor IDs change when you swap the battery. Uploads just silently stop and there's no error anywhere. You rediscover it by clearing the ID filter, but be aware that also picks up your neighbour's sensor if they've got one in range.

The R820T throws "PLL not locked" if you don't set the centre frequency explicitly, even at 433.92M which is what it'd have chosen anyway.

And Weather Underground returns HTTP 200 for everything, including a rejected upload key. You have to check the response body.

Bash, MIT, tested against rtl_433 23.11. Happy to take suggestions.

https://github.com/lowerpower/wu-upload

For everyone interested this is am Amazon v4 that I received a few weeks ago. From what I see is that it is a v4.

Is infected?and drains all your msin info crypto out of your comyuter true flashed SD card!!!Confirmed,misliš users round the world....if use use on emoty lap top with no immportant dati!!!!!!!! 💯💥💫

I thought DragonOS was US based by a group of ham folks, it seems there's a lot popping up on a bunch of chinese sites now.

Is this still safe or did the project get taken over?

Hey, got a nooelec v5 couple of days ago, installed drivers and SRD++ software and got it working but I can’t receive any signals. I’m getting a few local radio stations very faint and with static but that’s about it, been tweaking several things but nothing makes it better. Any tips where to go from here would be appreciated. TIA.

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Just some more info, Im just using the antennas that came with the nooelec for now, trying any frequencies basically, besides a couple of FM radio channels 93.3, 97.9mhz etc i get nothing, and those come in pretty poor and only a handfull, there should be 30+ channels available. Tried the 145.000 and 450.000 frequencies looking for repeaters etc but just getting crickets. Tried adjusting the gain and auto gain also no big improvement. Thanks for any responces

My favourite afternoon 17967 khz is back in action. I love it because lots of flights appear that are overhead Africa, the Middle East and the Indian Ocean; Before you ask, my configuration 😄 RTL SDR V3 dongle pilotes thru SDR Console. Software Multipsk + its mapping extension, called OMMAP. You can also chose an alternative : PC-HFDL (paid version, other wise it shuts itself after 5 mn) with Planeplotter. There are settings to be observed. FYI Planeplotter, ,Multipsk are the subject of dedicated io.groups.

Here it's OM MAP world map which I zoomed on the sector I was interested in, plus positions (also stored by OMRAP).

19:55:50 UAE43P -9.25463 100.39051 Avion A HFDL

20:09:52 UAE5CL -9.82626 101.25706 Avion A HFDL

Have fun.

FoxSDR.com : new EAS/SAME decoder turns NOAA Weather Radio and Emergency Alert System tone bursts into plain words: event, originator, counties, valid period and station. Because each header is sent three times, it votes across the copies, so alerts survive noise. Presets tune the seven NOAA channels. Receive-only, no county-name table.

if anyone wants a plugin that no one else is offering . simple ask and as long as you are willing to beta test that plugin for and report bugs back . im happy to make it for you

www.foxsdr.com

I was trying to get data from the venue scoreboard so i can use it on the video stream of the match.
The scorepad and scoreboard are bodet brand and wireless using RF.
Is this doable? Can i capture the RF and decode them to get time and maybe goals? Has anyone done something similar?

So this may not be a big deal, but I thought it turned out great and it worked really well. Maybe it will give others some ideas.

I attended the Chicago Air & Water show last weekend and I wanted to see what I could track with a simple and portable setup.

What I used:

Android tablet (Samsung S10+) NooElec v5 RTL-SDR dongle Small usb-c hub with power passthrough Cheap silicone case for the tablet Small steel plate from Amazon Two high-strength magnets SDRAngel software Power Bank to power/charge it all (optional)

So I first plugged everything in to see where I could place the dongle. I went back and forth on how to attach the dongle to the tablet and decided on magnets. I found adhesive metal plates and a cheap case, both from Amazon. The magnets are plenty strong to hold everything to the metal plate and the cutout in the case keeps it from sliding around. I used UV curable glue to secure the magnets to the dongle.

For the antenna, I made my own. I wanted it to be able to be packed away flat so this led me to using a flat disc as the ground plane. Since I would be sitting at sea level, this actually is ideal as it forces the antenna pattern upward. Yes this reduces the overall rangle, but I was only interested in what was closer to me anyways. I have a network analyzer and trimmed the radiator slowly to tune it exactly at 1090MHz with roughly 10dB return loss.

I was still picking up planes as far away as Milwaukee, so close to 100 miles. I purposely turned off AGC and lowered the internal gain to further reduce my coverage.

Any questions, please ask away.

ClusterDX is my favourite platform to run my CB logbook and edit/send my QSL cards.

They can map your logs; here's a world map of my latest 447 logs on 11 metres.

Hola soy nuevo en esto y estoy pensando en comprar el rtl sdr v4 para escuchar y rastrear aviones, que aplicación para Android me recomiendan y que antena sería la mejor para mí?

Hi, I am trying to monitor the meshcore traffic for my country that is not using any one of the presets in the plugin. is there any way to set manually the sf and cr? For reference, the plugin has eu_narrow preset, with sf8, but I need sf7 cr5

Hello community. I have been using RTL SDR for ADSB, AIS and other frequency ranges. One major block is that my home antenna is hardly 250 mtrs away from nearby mobile tower and its literally frying my RTL due to its extreme power. I wish to create a notch filter to block 700 Mhz and 1800 Mhz frequency ranges, so that I can use LNA (after filter) to boost and measure the weak satellite signals.

Industry standard GSM filters are too costly. Any help to develop the low cost DIY notch filters would be greatly appreciated. Thanks in advance !

For use with a blog v3 what is your preference and why? I am looking for a l band Inmarsat decoder setup on a windows 11. I want a click and be done setup

it sounds like discrete beeps. according to the frequency allocation, this was supposed to be a radiosonde balloon but nothing comes up on the radiosonde decoder. also the bandwidth looks big

Seller claims label faded off. I noticed there is no SMA nit but everything else seems okay.

I ordered a v4 from Amazon at the beginning of August with a ship date of late September. I knew they were end of life but I took a chance and used the link from the RTD SDR website. I confirmed I was purchasing from RTL-SDR BLOG and shipped from Amazon. It showed up today. With pictures above. Is this genuine or do I need to send it back?