The KiwiSDR server is a wonderful mid-range software defined receiver that you can share with your friends all over the world. It is designed from the ground up for remote listening.
Many newer software defined radio’s contain their own server. So we have a radio with an Ethernet port on the back, like my Flex 6300. More typically, you just use your station computer to serve the radio on the Internet. But John Seamons, the principal designer of KiwiSDR came up with a different idea.
KiwiSDR is an add-on option for a single board computer. The computer is the BeagleBone, which is sort of like the Raspberry Pi. BeagleBone has a fast CPU, lots of I/O connectors and runs Linux. It costs less than $50. KiwiSDR is an accessory board that just plugs into the BeagleBone. You can buy the radio separately, or get the whole kit from SeeedStudio for $300.
So why get excited about KiwiSDR? Mainly connectivity. KiwiSDR provides a 0-30 MHz software defined radio receiver that you can connect easily to a network and share with up to four simultaneous users. The front end is based OpenWebRX, and you can listen to hundreds of these receivers online, right now.
Unlike the cheaper RTL-SDR dongles, KiwiSDR uses the LTC2248 14 bit ADC sampling at 65 MHz. This provides complete coverage up to 32 MHz. With web-based front-end, you can create four separate receivers at the same time. The radio also contains a GPS receiver. The overall design is open source, and source code is available at Github.
KiwiSDR Server Originated on Kickstarter
KiwiSDR started out as a Kickstarter project in 2014. So a few hundred radio listeners got to contribute to and participate in its creation. If you are interested in the technical details, you might take a look at the original design review document.
The creators go into a lot of detail about their design trade-offs to keep the cost of the unit low. This includes selecting at 14-bit rather than 16-bit analog to digital converter and the cheap BeagleBone single board computer as a platform.
If you are interested in buying a KiwiSDR server, here is a very detailed review of its performance.