KiwiSDR: tuning into new numbers stations

26 May 2017

If you're already familiar with the KiwiSDR project, you can check out our new receiver map and scroll down to read what else the Priyom team is doing with it!


For many including myself, discovering and listening to numbers stations live was only possible thanks to the University of Twente WebSDR. I think it's fair to say that it has been such a unique and successful receiver, it was a major milestone and became a staple of shortwave listening.

Over the past year, a new generation of receivers has spread: the KiwiSDR. Hopefully you've already come across it! Just like the U-Twente WebSDR, KiwiSDR is a Software-Defined Radio tunable over a web interface; and it replicates that awesome feature of offering the full, continuous, wideband shortwave spectrum, from 0 to 30 MHz. But even better, unlike past receiver solutions, it's available out of the box to anyone, as a self-contained, hardware + software commercial product, for the very fair base price of $299. Pretty amazing for this sturdy little box, especially when you know how expensive high-end radio gear can get, or how limited and frustrating custom setups can be!

What's more, is that the design is completely open-source. The success of the project has fostered a little community: operators tweaking the code of their receivers, developing third-party extensions, users submitting a lot of feedback and suggestions for improvement, and even contributing patches getting merged into the periodic software updates.


So it's no surprise to me that this new generation of receivers has already quickly spread onto the six continents, and we at Priyom are thrilled about what this enables for numbers stations! The U-Twente WebSDR was great for signals on any frequency making it to Western Europe; the KiwiSDR network opens new horizons, with unfamiliar automated voices, and new shortwave mysteries. The Spanish voice of Russia's foreign intelligence's elusive V07, audible only once a week on the West Coast of the US; V13 New Star Broadcasting from Taiwan, V24 from South Korea, and North Korea's recently reactivated V15 on Radio Pyongyang, each with their musical call-ups; a crystal-clear Buzzer on Eastern-European KiwiSDR receivers, and the other new 24/7 Russian military channel markers: the Air Horn and the Goose; or the bountiful Chinese military and navy networks M89 and M95 for the morse addicts; so far and weak before, now all audible within a single click.


The Priyom team is proud and excited to do its part to help in this successful ecosystem. Two of our members have already contributed patches to the KiwiSDR interface. We have helped to put in place a #kiwisdr IRC chatroom on freenode, and we are now working on external developments to get the best out of this receiver network.

The shortcoming of KiwiSDR receivers is that they only have capacity for 4 users at the same time. This is partially offset by the upside that these receivers are so easy and affordable that numerous radio amateurs have shared one from their home network. The downside however is that this doesn't always allow for a 24/7 quality connection and uptime. To make all this invisible to the user, we created a little behind-the-scenes project, the pavlova dispatcher. When you click on an announcement in our numbers station schedule, for a transmission beamed towards North America or the Pacific area, the dispatcher will automatically probe, pick and redirect you to the best KiwiSDR receiver available at the moment; so you don't have to worry about anything. Nifty!


Our second, and more striking, side project is the dyatlov map maker. We are hosting a map of worldwide wideband shortwave receivers, specialized for numbers stations and the other radio oddities that we love. Check it out, we've been told it's pretty cool! This is an alternative and improved version of other existing radio receivers maps. The receivers are color-coded for quick visual clues: for example red ones are available with open user slots, but purple ones are temporarily offline (full legend here). Open the map, pick a receiver wherever in the world, and tune to your frequency of choice, explore the waterfall display, there you go!

All of this was possible only thanks to the fruitful cooperation with, and kind help from, the KiwiSDR project: so thank you! Indeed, the map is mostly just populated with KiwiSDR receivers for now; but we already have ideas about which other receivers and which new features we would like to add to the map next. What do you think? Send us your feedback on twitter @priyom_org!


This blog post will be followed by a part 2, where we will tell you more about how the KiwiSDR network is helping us study numbers stations, and some specific pieces of mystery we can unveil. Stay tuned!

Sending you some 8's and other good numbers,


Note: the indicated KiwiSDR receiver price of $299 is meant to be just that, an indication of what price range to expect, as of writing this. Additional varying taxes, shipping fees, and import duties may apply depending on where you order from, and the actual retail price may of course still depend on the retailer you choose. For the tinkerers, a board-only version is also available for cheaper!