KiwiSDR Independent SDR Network Receivers are stand-alone SDR (software-defined radio) receivers that operate across a frequency range of 10 kHz to 30 MHz, encompassing very low frequency (VLF) to high frequency (HF) bands. These receivers come pre-installed with OpenWebRX and feature an integrated GPS receiver. Its ease of use and comprehensive features make it one of the best HF SDRs available. The Kiwi SDR2 is different from other SDRs. It is a standalone device that attaches to your local network and is optionally accessed through the Internet. A browser is used to connect to the user interface. Most other SDRs generate raw IQ data and need to be connected directly to a PC or laptop running OS-specific, installed software.

KiwiSDr2 top corner view

Browsers supported include Firefox, Chrome, Safari and Opera on Windows, Linux and Mac. A version of the interface for mobile devices is under development. Until then, the browser interface will work on iPad and Android devices with a large enough display. The Kiwi SDR2 supports up to four (now 8, see update below) simultaneous connections, each with their own independently controlled audio and waterfall channels. An extension interface allows advanced signal decoding directly in the browser interface without installing additional software. The most popular are the integrated WSPR decoder and Time Difference of Arrival (TDoA) signal direction finder. Kiwi2 also includes a software-defined GPS receiver used to calibrate the SDR frequency and obtain in time-of-day.

Update: KiwiSDR now supports 8 simultaneous receive channels through a free software upgrade, giving users twice the capacity of previous versions at no additional cost. Existing units can be upgraded automatically by connecting to the Internet—no antenna required. Customers who purchase a KiwiSDR will automatically receive the software update after initial setup, doubling the number of available channels without the need to purchase a second receiver, additional power supplies, or antenna-splitting hardware. Enjoy greater flexibility, expanded monitoring capabilities, and support for more simultaneous connections with the enhanced 8-channel KiwiSDR.

The Kiwi SDR2 features a 14-bit ADC for excellent dynamic range and a sturdy metal case with ample cooling holes for heat dissipation, making it suitable for continuous operation. It includes USB ports, an Ethernet connection and a 5.0 VDC input. The Ethernet port is essential for connecting the SDR to a LAN (local area network), enabling operation via a web browser. The device also has three SMA sockets for the GPS antenna, an external clock input, and the RF input from the antenna.

KiwiSDR connector view

Inside, the Kiwi SDR2 houses a BeagleBone Green board preloaded with Debian 11.9 and all necessary SDR software. Additional features include a switching power supply shield to minimize RF noise, a gas discharge tube for surge protection and a 0 to 31.5 dB electronic attenuator for handling strong signals.

The setup process involves connecting the GPS antenna, power lead, and Ethernet cable to the home network. Once powered on, users can access the device via a local IP address or through an internet proxy. The admin page allows for various configurations, including security settings and public sharing options. The control panel on the display lets users adjust frequency, mode, and band, and use built-in data decoders. The Kiwi SDR2 is praised for its extensive capabilities and ease of use, making it an excellent out-of-the-box solution for SDR enthusiasts.

Internal BeagleBoard

A great deal of information is waiting for anyone interested in these great receivers at the KiwiSDR webpage.

The package inc

ludes: A short SMA-to-SMA patch cable, a GPS antenna, and the Kiwi SDR2 itself.

NOTE: DC power cable or supply is not included. 5 VDC at 1.5 A minimum to the 2.1mm input is required, and it is very important that the DC power to the KiwiSDR Network Receiver is well filtered, to preserve the high dynamic range and low noise floor of the receiver.

Many KiwiSDR2 owners use a quality linear transformer power supply, such as the type used by audio enthusiasts typically available on eBay and shipped from China. They are built for many different voltages, so be sure to get one that is specifically 5 VDC at 1.5 A minimum.

If cost or shipping time is a factor, do not use just any 5 VDC wall plug switching power supply. The best well-regulated RF quiet switching power supply that is readily available is the Meanwell GST25A05-P1J. These power supplies are used Internationally, so the AC power cord is not supplied. In the USA, use a typical electronics power cord, IEC 320-C13 NEMA 5-15P, which most of us have on hand.

Alternatively, a separately purchased USB A to 5.5/2.1mm power cable (not supplied) can be used with a noise free and stable USB A 2.1A wall adapter, which is a tall order. While genuine legacy USB A Apple iPhone chargers had the best regulation at the time, finding an RF quiet wall power cube is nearly impossible. The jury is out whether any of the present-day USB C power cubes have sufficient filtering and regulation. But the specification demands of USB C should improve the chances of finding a capable USB C to 2.1mm power cable or a USB PD (power delivery) adapter.

included accessories