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WebSDR – Shortwave Radio on the Internet
- exabrial 8y agoLast time this was posted to HN I spent an entire 6 hours listening to Numbers Stations, international broadcasts, and wrote a DTMF decoder in Java. I don't recommend visiting this if you have actual work to get done.
- rjplatte 8y agoThanks for the idea. I ha(d)ve hours to bill...
- escherplex 8y agoCute. So now from your laptop with audio piped into a rec-room amplifier via Bluetooth you can have a Euro-based SW receiver complete with 'waterfall' display and U/LSB (moderate sensitivity) plus with the Google 'Radio Garden' web site you can listen to American pop music in stereo live from Petropavlovsk on the Russian Kamchatka peninsula, an area of significance during the cold war.
- peetle 8y agoRuss Hanneman would be proud.
- jlpicard 8y ago^ This guy fucks
- LinuxBender 8y agoWith enough of these set up around the world, it would be a great way to test skip conditions and channel noise floor levels. The US military does this with ChirpSounder. I would love to see a civilian version that just listens all around the world.
- vvanders 8y agoIf it's propagation you're interested in then RBN[1] does a good job of that by parsing morse code and callsigns. Sadly the map no longer exists due to the changes in Google's Map API pricing. [1] http://www.reversebeacon.net/main.php http://www.reversebeacon.net/main.php
- LinuxBender 8y agoNice, I had not seen that. Thankyou.
- waffle_ss 8y agoI found WebSDR a while back and was fascinated by it, however I was surprised to find out the author, an EE/CS prof[1], has a very closed source view of both the client-side JavaScript code as well as the server-side code. I wanted to poke around the JavaScript and see what I could learn but that's explicitly disallowed by the license[2]: > Since the intended use of this code involves sending a copy to the client computer, I (PA3FWM) hereby allow making it available unmodified, via my original WebSDR server software, to original WebSDR clients. Other use, including distribution in part or entirety or as part of other software, or reverse engineering, is not allowed without my explicit prior permission. The server-side code is only available if you email him with plausible reasons you will use it[3]: > Q: Where can I download the server software? > A: Nowhere. However, I distribute it (without cost) via e-mail to people who are setting up a publicly accessible server ... He's well within his rights of course to share his code however he pleases. But it did kill off a fun little idea I had for a Twitter bot pretty quickly since I can't touch the code. [1]: http://wwwhome.ewi.utwente.nl/~ptdeboer/ http://wwwhome.ewi.utwente.nl/~ptdeboer/ [2]: http://websdr.ewi.utwente.nl:8901/websdr-sound.js http://websdr.ewi.utwente.nl:8901/websdr-sound.js [3]: http://websdr.org/faq.html http://websdr.org/faq.html
- MrQuincle 8y agoIn the Netherlands reverse engineering is legal for quite a few reasons. It's written down in the Auteurswet (Dutch): https://wetten.overheid.nl/BWBR0001886/2009-01-01#HoofdstukVI_Artikel45m https://wetten.overheid.nl/BWBR0001886/2009-01-01#HoofdstukV...
- waffle_ss 8y agoThat's good to know, but out of respect for the author's wishes I'll continue to invest my time in other projects.
- sudder 8y agoThe server software is available here: http://strezhi.ru/temp/2015/websdr-dist11.tgz http://strezhi.ru/temp/2015/websdr-dist11.tgz Binary only, but not obfuscated or anything like that, so reverse engineering it isn't too onerous.
- resters 8y agoCheck out 1.8 to 1.9 MHz this weekend actually starting right now.
- mikece 8y agoThis reminds me... I've been wanting to write two apps: one to scan SDR looking for CW, RTTY, and other digital(ish) modes and then send an alert to me (SMS, email, or push notification) that QSOs were found, along with a separate alert type when it finds a CQ call. I don't suppose anyone has done an app like that, have they?
- threeio 8y agoSounds similar to some of the CW Skimmers.. http://www.dxatlas.com/cwskimmer/ http://www.dxatlas.com/cwskimmer/ is the primary one, however its pay and windows only
- jcims 8y agoSDRSharp has a bunch of plugins to scan bands and stroll through bands. You could pipe that to CW Skimmer and figure out how to get the data out of CW Skimmer (telnet server, log file, etc).
- wglb 8y agoThere is something already like this: http://www.reversebeacon.net/main.php http://www.reversebeacon.net/main.php I use this to see if my antenna is effectively transmitting any kind of signl: http://www.reversebeacon.net/main.php http://www.reversebeacon.net/main.php The devices, which are spread all over the world, watch the whole cw band.
- madengr 8y agoI wrote one that scrapes NBFM and AM. https://github.com/madengr/ham2mon https://github.com/madengr/ham2mon
- threeio 8y agoI'll also point out that https://sdr.hu/ https://sdr.hu/ provides many many other locations that you can listen from
- xvf22 8y agoThanks, I forgot about that one. I usually use http://www.websdr.org/ http://www.websdr.org/ and I find these sites quite useful to check propagation.
- dang 8y agoFrom 2015: https://news.ycombinator.com/item?id=9574966 https://news.ycombinator.com/item?id=9574966
- jakobegger 8y agoCould you use something similar to detect digital / data radio transmissions? Motivation: here in Linz we have electronic signs at bus and tram stops that display how many minutes until the next bus/tram arrives. I believe those signs somehow get their data via radio (they have antennas). I know nothing about the technology used, but since they were installed more than 15 years ago they probably don't use the cellular network. The company also offers an API with live data, but for some reason the estimates from the API are not as precise as those on the signs. So I'd love to somehow intercept the data sent to the signs. Does anybody have an idea how to go about that? I know nothing about how radio works.
- vvanders 8y agoIt's probably something on the VHF frequency which you can pick up via a cheap $15-20 RTL-SDR. If it was installed that long ago there's a good chance it runs on something really simple like DTMF tones. Something like the 433Mhz ISM band parsing can give you an idea of what's possible[1]. [1] https://www.rtl-sdr.com/tag/rtl_433/ https://www.rtl-sdr.com/tag/rtl_433/
- dest 8y agoLook at RDS data on FM. There was a CCC video about this a few years ago
- russdpale 8y agoShout out to the simple design! Made in '07, with the class of '97!
- deleted 8y ago[deleted]
- tlrobinson 8y agoFYI you can link directly to frequencies / modes like this: http://websdr.ewi.utwente.nl:8901/?tune=198am http://websdr.ewi.utwente.nl:8901/?tune=198am Also, the neat thing about this particular instance of WebSDR is has a custom SDR receiver that covers ~30MHz of spectrum, whereas most of the ones listed on http://websdr.org/ http://websdr.org/ are much narrower.
- wglb 8y agoRelated: http://www.reversebeacon.net/main.php http://www.reversebeacon.net/main.php
- gorkish 8y agoThis is a great project; unfortunately the guy who writes and maintains it (regardless of his talent) is kind of a dick. Notice how there is only one "wideband" receiver despite the simplicity of the hardware? There is a reason, and it doesn't mesh well with the hacker ethos that we are all so fond of around here. Anyway as a basic rundown, the implementation does a very large FFT on the high samplerate data coming in from the ADC and then individual receivers can be constructed by filtering and decimating in the frequency domain followed by doing an IFFT which makes the prospect of running many hundreds of receivers achievable on commodity hardware without having to process the full ~1+gbps dataset for each Rx. The specifics are a bit more complicated, but that is the general idea. I would encourage anyone who is deeply interested in this technique to please follow the work of Phil Harman VK6PH and Warren Pratt NR0V who are implementing the same type of processing which they term "Direct Fourier Conversion Receivers" on top of the OpenHPSDR hardware platforms. The code including the software and verilog is all open, and there are open OpenHPSDR hardware designs as well.