- Most used nowadays: HTML5 WebAudio, since this has been availablein most web browsers since several years:
- Firefox version 17 or later
- Chrome version 10 or later
- Safari version 6 or later
- Opera version 15 or later
- Edge (as supplied with Windows 10)
- Essentially only for Internet Explorer, you can also use Java applets; for this, you neednot only a webbrowser, but also version 1.4.2 or newer of Java working on your computer.Try http://javatester.org/version.htmlto find out if you have Java and which version it is.You may need to enable Java applets per site; see here.Some WebSDR sites have disabled Java support; those sites can only be used with HTML5 WebAudio.
So, which one do you use?WebSDR sites try to detect what your browser can do.If HTML5 WebAudio is available, it will be used; otherwise, Java will be tried.
If you don't get audio, try the following:
- At the top right, click the 4 vertical dots, and then Settings.
- At the bottom, click Advanced.
- Under "Privacy and security," click Site settings.
- Select "Sound"
- Select "Add" and enter "http://*"
Note that the above effectively disables Chrome's "autoplay" policy forall http sites.
Although stopping automatic sound from advertisem*nts is a noble idea,I think Chrome's autoplay policy is fundamentally wrong. Instead of trying to guess whatthe user wants, the browser should simply ask the user whether he/she wants to allow thepage to play sound (and remember that for later visits, of course).
You can enable audio via Safari > Settings for this web site> Autoplay > Allow all Autoplay.
(thanks to M0IFA for these instructions)
If only those on port 80 work, you're probably behind a firewall thatonly allows port 80 (and a few others). This is often the case in public WiFi networks and office networks.
If only those on ports other than 80 work, you're probably behind aweb proxy server, which doesn't know how to handle the (non-standard)audio and waterfall data streams. The proxy server may also be in your internetservice provider's network.
On Android devices, these include Firefox, Chrome and Opera (but not Opera-Mini);and even recent versions of Android's built-in browser should work.
On iPhones, iPads etc, you can use the built-in Safari browser,but only if you have iOS version 6 or later.
Somehow, iOS treats the WebSDR audio as the latter.So please check that you haven't accidentally muted the system sounds.On some devices this is a software switch, on others it's a physical hardware switch.
Decoding them serverside is not an option either, because of the CPU load for the server.
Furthermore, I think most DRM programmes canalso be heard directly on the broadcaster's website, so there is not much reasonfor listening to them via a WebSDR receiver.
- what kind of SDR hardware (see below for what is supported)
- what kind of internet connection, computer, and Linux installation
- what frequency band(s)
- and what does that add to the current offering on websdr.org (see the next question) ?
I have tentatively stopped distributing the software, for a number of reasons,one being that the latest distributable version I've made is rather outdatedand I haven't gotten around to making an update.Development of my own site (http://websdr.ewi.utwente.nl:8901) continues though.
If the SDR has some kind of synthesizer or other configuration settings,the WebSDR software will not take care of this. You'll have to use othersoftware to configure it.
Other SDRs typically use a fast A/D converter and digital hardwareto filter part of the spectrum; they are typically connected to the PCvia USB or ethernet. Unfortunately, there is no standardization among the interfaces for theseSDRs, which makes it hard for me to support them. A generic interface for them is being added, but for now they cannot be used.
The (in)famous RTL-SDR dongles (cheap VHF/UHF SDRs) are now supported.Note that these SDRs have a rather small dynamic range, so should only be used in situationswhere there are no very strong signals.If you want to use these, please check carefully that they are not being overloaded,e.g. by comparing their reception (using normal SDR software) to e.g. a normal non-SDRreceiver; in particular, pay attention to weak signals: they should not disappear intothe noise.
The WebSDR at the University of Twente (http://websdr.ewi.utwente.nl:8901)
Most labels in the longwave and mediumwave range are maintained manually by myself,based on remarks people send me and my own observations. This list is not available,but that wouldn't be very useful as it has been tailored this location.In general, lots of good data on is available at https://www.mwlist.org.