Astonishing! Thank you very much for sharing..
This sentence really stuck out for me - "I was proud! I was tired! I was amazed that all those things I received are all around us, everywhere, all at once – if you know where to look. :O"
This page was very slow to load for me, probably partly because it's being hugged by HN. But it would help a lot if images had the `loading="lazy"` attribute, and if they were compressed to about ~100KiB each instead.
Sadly, you can't really get NOAA satellite images any more. NOAA-15 and 19 were decommissioned August 19, 2025, and NOAA 18 was decommissioned in June. It's my understanding that you'll need a much more powerful antenna to get images from the new satellites. Still, SDR is great fun. It's incredible to realize that all this information is stored in electromagnetic waves and passing through us all the time.
Over a decade ago I played with SDR sharp and a tv dongle and got to listen to very cool stuff. I don’t know if SDR sharp still exists, I think it was closed source at the time but free. I remember one could use it to decode stuff and then map to virtual ports to redirect to other software that expected an input from specialized hardware like ship signals and stuff like that.
more than 15 years ago I got a chance to play with gnu radio and back then it was hailed as the next big industry.. fast forward, and beyond the hacking community (and the hobbyist), it still has not taken over.
Receiving 433Mhz sensor data using rtl_433[0] with an RTL SDR was a lot of fun when I started doing it last year. There's MQTT output if you want to send it to Home Assistant, et. al., as well as simple text output to stdout. It was great fun seeing my neighbors' sensors, tire pressure sensors in passing vehicles, etc.
There a ton of devices that use 433Mhz. You can also extend rtl_433 pretty easily.
I've been wanting to experiment with SDR triangulation. There are some off the shelf options, but I think it would be fun to cobble something together using dongles.
I got a walkie talkie set as a Christmas present when I was 8. Which was kind of an evil thing to do given I had no siblings or friends to play with. One day I turned one set on and listened for a while and I thought I heard someone talking behind all the static noise. So I said something and was shocked to hear the voice talking back to me. Fast forward a few decades, next week is my wedding and that voice on the other side of the radio is my best man.
I brought a family-pack of walkie-talkies for my wife and my two teenage boys to use while we were hiking around various Austrian mountains, one summer vacation.
We rarely used them much, since we were often walking in a family unit, so during one of our breaks I took one out, turned it on, and blasted off into the ether "hello hello, anyone out there wanna chat?" .. did this off and on for the afternoon, when suddenly, a voice answered back "yes! who is this?" ..
A family waaaaay the hell down the mountain rage, deep in the valley, had by chance heard my call .. so the boys spent the afternoon getting to know all of the 5 kids in that family that were all drawn to the conversation.
It was awesome, for the rest of the week, our kids and theirs just chatted away .. what had started out to be, a little bit of a mundane trip for the kids, turned out to be a hilarious social experience.
We call for them every time we're out that way - never met them, but for the past 3 years, the conversations have continued and it has been a great alternative to the mobile phones we have been troubled with up in the cabin, at times.
Like 13 years ago when I was doing FPV I remember soldering my own skew-planar/quadrifilar antennas with bendable wire ha, the photo of the short yellow dipole reminded me of it. I think it's a dipole or double-dipole not sure.
I was informed maybe 7 or 8 years back that my electric company would be replacing my analog meter with a smart one and always intended to try and glean more information about my electric consumption habits from it. It took me a lot longer than I intended, but last year I finally bought an RTL-SDR in the hopes of being able to get realtime info from the meter. Unfortunately, it seems that it's not one of the ones that emits consumption info over ISM bands for consumption by household appliances (so far as I can tell) and I ended up only capturing info from TPMS sensors off of passing cars (which was cool, but not really what I was looking for).
Do note that if you purchase an RTL-SDR these days, you'll probably get a v4 which, at least as of last year, does not play out-of-the-box at all with the software available on the Ubuntu apt repos and the RTL-SDR drivers that ship with 24.04 out-of-the-box — there were some hardware protocol/interface changes between v3 and v4 that make the old drivers incompatible and you'll get a litany of misleading or non-specific errors if you try without downloading and installing the latest drivers from GitHub (or somewhere).
People are commenting about issues loading the images leading to them abandoning reading the article. Here is a fully cached copy of TFA, but note that the videos (and images, but especially the videos) load _really_ slowly https://web.archive.org/web/20240317122351/https://blinry.or... (but they do load if you wait long enough).
A few months ago when there was a lot of emergency services activity in my area and I didn't know why, I was reminded that no-one in my region is contributing a feed to Broadcastify.
I went down the tunnel of using SDR to recieve those transmissions, and share them online.
Then I went a bit further.
What if you could transcribe the broadcasts into something like a text feed? What if you could add location information somehow to monitor where things were going on in your region? Could you use AI to somehow organize the data into a more useful format?
What if this data was valuable? Maybe you could sell this as a service? Who would buy it? Public safety organizations? Hospitals? News organizations?
I spent a few days worth of freetime figuring out how you'd do someting like this, and got to a place where I figured it was conceptually possible.
Then somewhere in my googling, I stumbled across this site: http://citizen.com/ - and realized that someone had already turned my idea into what looks like a pretty mature product.
Ahh well. I'm sure my billion dollar idea will come later.
In the meantime, I'd still like to mess with SDR at least so I can know what's going on around me next time there's a fire or other public safety incident, before it gets reported on.
> A few months ago when there was a lot of emergency services activity in my area and I didn't know why, I was reminded that no-one in my region is contributing a feed to Broadcastify.
Maybe instead of emergency services activity, it could be other types of activities (hazards, local events, nextdoor alerts, local business/SIGs rss feeds, etc), it is all just local info and knowledge aggregation endpoints and archives that have over-the-air and terrestrial distribution channels.
The paging system was unencrypted around here the last I looked (that was during covid). And there was software that could decode the transmissions. The SDR would easily pick it up.
One of the hospitals had been using it and would page people with PII -- including which people were in which room. So you could kinda see what was happening in the hospitals -- particularly during covid.
There kinda was a life cycle, seeing people admitted, O2 alerts firing off, and then the morgue being called to a room.
Overall, it was both interesting to have insight into something that you weren't ever going to be allowed to have access, and also very very sad.
Listening to pagers is illegal in US from ECPA of 1986. It is the same law that banned listening to the analog cell frequencies, which still applies even thought that is long gone.
There is no way that they will know or care if you don't share messages.
49 comments
[ 3.0 ms ] story [ 68.3 ms ] threadLooks like hug of death strikes again!
https://web.archive.org/web/20250908132643/https://blinry.or...
There a ton of devices that use 433Mhz. You can also extend rtl_433 pretty easily.
[0] https://github.com/merbanan/rtl_433
https://www.crowdsupply.com/krakenrf/krakensdr
We rarely used them much, since we were often walking in a family unit, so during one of our breaks I took one out, turned it on, and blasted off into the ether "hello hello, anyone out there wanna chat?" .. did this off and on for the afternoon, when suddenly, a voice answered back "yes! who is this?" ..
A family waaaaay the hell down the mountain rage, deep in the valley, had by chance heard my call .. so the boys spent the afternoon getting to know all of the 5 kids in that family that were all drawn to the conversation.
It was awesome, for the rest of the week, our kids and theirs just chatted away .. what had started out to be, a little bit of a mundane trip for the kids, turned out to be a hilarious social experience.
We call for them every time we're out that way - never met them, but for the past 3 years, the conversations have continued and it has been a great alternative to the mobile phones we have been troubled with up in the cabin, at times.
edit: I think it's just a dipole
It runs on an Orange Pi Zero 3 SBC.
Do note that if you purchase an RTL-SDR these days, you'll probably get a v4 which, at least as of last year, does not play out-of-the-box at all with the software available on the Ubuntu apt repos and the RTL-SDR drivers that ship with 24.04 out-of-the-box — there were some hardware protocol/interface changes between v3 and v4 that make the old drivers incompatible and you'll get a litany of misleading or non-specific errors if you try without downloading and installing the latest drivers from GitHub (or somewhere).
I went down the tunnel of using SDR to recieve those transmissions, and share them online.
Then I went a bit further.
What if you could transcribe the broadcasts into something like a text feed? What if you could add location information somehow to monitor where things were going on in your region? Could you use AI to somehow organize the data into a more useful format?
What if this data was valuable? Maybe you could sell this as a service? Who would buy it? Public safety organizations? Hospitals? News organizations?
I spent a few days worth of freetime figuring out how you'd do someting like this, and got to a place where I figured it was conceptually possible.
Then somewhere in my googling, I stumbled across this site: http://citizen.com/ - and realized that someone had already turned my idea into what looks like a pretty mature product.
Ahh well. I'm sure my billion dollar idea will come later.
In the meantime, I'd still like to mess with SDR at least so I can know what's going on around me next time there's a fire or other public safety incident, before it gets reported on.
Maybe instead of emergency services activity, it could be other types of activities (hazards, local events, nextdoor alerts, local business/SIGs rss feeds, etc), it is all just local info and knowledge aggregation endpoints and archives that have over-the-air and terrestrial distribution channels.
Fifty Things you can do with a Software Defined Radio - https://news.ycombinator.com/item?id=39728153 - March 2024 (40 comments)
One of the hospitals had been using it and would page people with PII -- including which people were in which room. So you could kinda see what was happening in the hospitals -- particularly during covid.
There kinda was a life cycle, seeing people admitted, O2 alerts firing off, and then the morgue being called to a room.
Overall, it was both interesting to have insight into something that you weren't ever going to be allowed to have access, and also very very sad.
There is no way that they will know or care if you don't share messages.