The KiwiSDR is an up and coming VLF/LF/MF/HF capable SDR that has a large 30 MHz of instantaneous bandwidth and coverage from 10 kHz to 30 MHz. It is designed to be low cost and used as an online internet based SDR in a similar way to how WebSDR is used, however KiwiSDR is designed to be used with the OpenWebRX software from András Retzler, HA7ILM. It uses a LTC 14-bit 65 MHz ADC and Xilinx Artix-7 A35 FPGA, and also has an integrated SDR based GPS receiver which is used to automatically compensate for any frequency drift from the main 66.6 MHz oscillator. The features of the KiwiSDR include:
100% Open Source / Open Hardware.
Includes VLF-HF active antenna and associated power injector PCBs.
Browser-based interface allowing multiple simultaneous user web connections (currently 4).
Each connection tunes an independent receiver channel over the entire spectrum.
Waterfall tunes independently of audio and includes zooming and panning.
Multi-channel, parallel DDC design using bit-width optimized CIC filters.
Good performance at VLF/LF since I personally spend time monitoring those frequencies.
Automatic frequency calibration via received GPS timing.
Easy hardware and software setup. Browser-based configuration interface.
The KiwiSDR is currently in beta testing and has released two OpenWebRX beta test sites which can be used at:
On this episode of Hak5 (a popular hacking and security themed YouTube channel) Darren and Shannon discuss OpenWebRX, a SDR web broadcasting and remote control tool that is compatible with the RTL-SDR. OpenWebRX is similar to the WebSDR software in that it allows people to connect to remote SDR’s on the internet and tune them to any station within their currently set bandwidth frequency range. Many already functioning online OpenWebRX receivers can be found in the database at sdr.hu.
In the first part of the video the Hak5 team explore the worldwide SDR’s on the sdr.hu website. Then in the second part they show a demonstration on how to install the OpenWebRX software in order to create a SDR broadcast with an RTL-SDR.
FREE SDR receivers all around the world with OpenWebRX – Hak5 1916
From Reddit we’ve learned of a new web based SDR receiver software for the RTL-SDR called OpenWebRX. This python based software allows you to run a web server that allows multiple users to connect to an RTL-SDR and listen to it through a web interface. The web interface also allows the RTL-SDR frequency and mode settings to be controlled. The software appears to still be in beta, so it may have some bugs.
The author has also written his BSc. thesis on this software and it is available for reading here. The thesis describes his software design and implementation as well as some SDR theory and may be useful to anyone wishing to implement similar SDR software.