Getting started with WebSDR

Getting Started

Just like the flight tracking post, the first thing you’re going to want to do is figure out which website you’re going to use for WebSDR. Over the many years I’ve listened to shortwave radio I’ve primarily stuck with a single website, however some times I’ve branched out and used services like KiwiSDR, it all depends on where I want to listen from. I.e, if I pick an SDR based out of Wichita, Kansas, there’s a good chance I’ll be able to pick up on military communications from aircraft or ground stations in the nearby area. It all depends on how strong the receiver is, and where the receiver is located. So, I typically stick with . It’s based out of The Netherlands, and picks up quite a lot of communications from a large majority of the area. But, this is purely down to preference.

If you decide you’d like to use a website that isn’t Utwente, you’ll have to do some digging through Google in order to find a website that best suits your needs. This tutorial will be based around the Utwente website, however most websites have a similar layout, so you might be able to translate the information given here, to whichever website you decide to pick.

Understanding WebSDR

Before we dive into getting things setup, you’re going to want to understand what you’re looking at, before you begin changing things around. The 1st thing you’ll be presented with when you go onto the Utwente receiver is a button that says “Start audio”, simply click that, and proceed with the tutorial.

After you’ve done that, you’ll begin to hear static. In order to solve that, simply quick on the little check box directly to the left of “squelch” and the static will go away. However, just a heads up, sometimes squelch can filter out very faint communications, so you might just have to adjust the volume, and deal with the static.

So, the first thing you’ll see is the wave form, this shows the activity on loads of different stations. If you’re not familiar with how to use the wave form, leave it alone, for now. Below the wave form, you’ll see a box for you to enter stations, and some controls below it. To the right of that you’ll see the filter button, and below that you’ll see “squelch”, “autonotch”, and “noise reduction”. Below that you’ll see a button to record audio, if you click this, it’ll begin recording whatever you’re listening to on the current channel you’re tuned into.

To the right of that you’ll see a section that displays the audio you’re listening to, and then you’ll see some controls for the waterfall, which is apart of the wave form.

Below that, you’ll see a couple different tabs. Most if not all of these tabs do not serve a major purpose, unless you plan on getting very into WebSDR itself. We’ll dive into the Waterfall settings tab, and some of the other tabs, in a minute.

Adjusting Settings

The very first thing you’re going to want to do, is determine what you’re going to be using the website for. If you’re going to use the website to listen to encrypted military communications, you’ll need to gather a small list of frequent channels, and remember the stations on the list.

The main 4 channels I’ll use for listening to military communications are all on the “Upper Side Band”, so make sure you select USB under the channel input section, here.

The 4 channels I listen to are, 4724 kHz, 8992 kHz, 11175 kHz and 15016 kHz. On 8992 kHz sometimes you’ll hear people speaking in French, which is typically French military communications, just ignore it, sometimes their communications bleed into the frequency, and you’re able to hear it.

Next, you’ll want to adjust the filter to something that you feel is good enough. Most of the time I’ll adjust my filter to 3.75 kHz, but sometimes I’ll lower it using the “narrower” button directly to the right of the filter section. It’s all up to personal preference.

Under waterfall settings, I’ll keep the speed at slow, I adjust the size to large, keep the view to waterfall, keep the brightness where it’s at, and leave the last three options all unticked. Memories I don’t touch, the users tab shows online users, the Chatbox I rarely go into, the Logbook I don’t touch, Station info I rarely go into, S-meter plot is cool to see recent activity on a given channel and Advanced I leave just the way it is.

What am I listening to?

If you’re using the website to listen to encrypted military communications, that’s exactly what you’re listening to, encrypted military communications. The US military frequently broadcasts something called Emergency Action Messages using the frequencies you’re listening to, these messages consist of a string of alphanumeric characters, all letters of the English alphabet, and numbers excluding 0, 1, 8 and 9. These messages are typically 30-32 characters, and if they’re not, the operator will say that the message consists of (blank) characters. All messages are read using the NATO phonetic alphabet, so that the person receiving the message given by the operator, can understand what letters the operator is saying.

Skyking messages are a little bit more rare, but can be picked up using WebSDR on occasion. It isn’t 100% known what these messages mean, but they’ve been confirmed during numerous interviews with former and current military personnel to exist. It is believed that these messages are associated with strategic operations, however that’s just a theory and isn’t confirmed.

Skyking messages are almost always a code word, followed by the time, and then a two letter authentication code. Sometimes the code word can be something like a rock band, or popular movie.

Skyking messages typically follow the following layout.

“Skyking, skyking, do not answer.” then the code word, which is repeated twice, then “Time” which is followed by the minutes of the current hour, then “Authentication”, which is followed by two letters read out in the NATO phonetic alphabet, then “I say again”, which repeats the first couple of steps, and then “This is (callsign), out”, and then the message is over.

Sometimes you’ll hear test counts, which are various stations giving a test count, sometimes you’ll hear Andersen, sometimes you’ll hear Andrews, sometimes you’ll hear Ascension, you never know.

Sometimes you’ll hear phone patches as well, which are unclassified messages heard over HFGCS channels. In order for this to happen, the aircraft calls the ground station, requests a phone path, and then the aircraft gives either a 7 or 10 digit phone number to call, these are really cool, and you can hear some really interesting things over the phone patches.

Sometimes you’ll hear general air-to-ground traffic as well, which is typically very standard and not all that interesting.

In conclusion

It’s very important to remember that we’re never going to understand what messages are being broadcast during EAMs or Skyking messages. These messages are encrypted via one time pad, which means unless you’re given the pad, you’ll never know what the messages mean. It’s simply interesting to listen to the messages. Do not try and match the messages up to anything, as there’s no reason to believe that a large amount of messages equals any sort of military action, or anything like that.

Also, feel free to browse through some of the channels, check some of the bands, sometimes you’ll come across AM stations from various parts of the world, you’ll hear talk shows in different languages, popular music from different countries, and sometimes you’ll catch some interesting broadcasts from other countries military’s, it doesn’t hurt to be a little curious.

If you have any issues with navigating the site, or have any questions, do not hesitate to reach out to me via Twitter or Discord, and I’ll do my best to help you out.


After many days of technical issues, I’ve finally launched the Intel Doge forum. If you’re interested in getting involved, head on over to, and get yourself started by creating an account. Also, I switched hosting providers recently, and during the process, I lost every single blog post I’d had on the old Intel Doge website. So, I’m currently trying to get posts back onto the site so that people can keep up to date with things ongoing across the world.

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