Tagged: kiwisdr

Video Comparing the Airspy HF+ and KiwiSDR

Over on YouTube user icholakov has uploaded a video comparing the Airspy HF+ with the KiwiSDR. The Airspy HF+ and KiwiSDR are both high performance yet low cost SDR platforms. The differences are that the Airspy HF+ is normally connected directly to a PC (but can be run remotely too) whereas the KiwiSDR is designed to be run remotely only, and so can only be accessed through a browser platform. In addition the HF+ only has maximum live bandwidth of 660 kHz whereas the KiwiSDR samples the entire 30 MHz of the HF band. Both are very sensitive and fairly resistant to overloading, but the HF+ should be better in both regards.

In his video icholakov does side by side comparisons with each radio. He writes

Comparing short wave and medium wave reception from Airspy HF+ SDR Console 3 and KiwiSDR with its built in web server. Using the same 80m dipole antenna. No special noise cancelling on the Airspy HF Plus.

Airspy HF+ vs. Kiwisdr SDR Radio comparison

A Review of the KiwiSDR: 10 kHz – 30 MHz Wideband Network SDR

The KiwiSDR is a 14-bit wideband RX only HF software defined radio created by John Seamons (ZL/KF6VO) which has up to 32 MHz of bandwidth, so it can receive the entire 10 kHz – 30 MHz VLF/LF/MW/HF spectrum all at once. However, it is not a typical SDR as you do not connect the KiwiSDR directly to your PC. Instead the KiwiSDR is a cape (add on board) for the Beaglebone single board computing platform. If you’re unfamiliar with the Beaglebone, it is a small computing board that is similar to a Raspberry Pi. The KiwiSDR is designed to be a low cost standalone unit that runs 24/7, connects to your HF antenna and internet network, and shares your 10 kHz – 30 MHz reception over the internet with up to 4 simultaneous users.

The KiwiSDR
The KiwiSDR

The KiwiSDR kit retails for $299 USD (Amazon) (Direct from Seeed Studio), and with that price you get the KiwiSDR cape, a Beaglebone Green board, an enclosure, microSD card and a GPS antenna. If you already have a Beaglebone lying around, then you can purchase the KiwiSDR board only for $199 USD. 

Because the KiwiSDR is a network SDR, instead of connecting it to your PC it connects to your home internet network, allowing you to access it from any computing device via a web browser. Direct access to the SDR is not possible (actually it seems that it is, but it’s not easy to do), and all the computing is performed on the KiwiSDR’s on board FPGA and Beaglebone’s CPU before being sent to the network. Thus raw ADC or IQ data is never touched by your PC, your PC only sees the compressed audio and waterfall stream. So a powerful computer is not required to run the SDR. In fact, a mobile phone or tablet will do just fine.

In comparison, a $299 USD wideband non-networked SDR such as the LimeSDR uses a 12-bit ADC and can do up to 80 MHz of bandwidth over USB 3.0. But even on our relatively powerful PC (i7-6700 CPU, Geforce GTX 970 and 32 GB RAM) the LimeSDR can only get up to about 65 MHz on SDR-Console V3 before performance becomes too choppy.

But the real reason to purchase a KiwiSDR is that it is designed to be shared and accessed over the internet from anywhere in the world. You can connect to over 137 shared KiwiSDRs right now over at sdr.hu which is a site that indexes public KiwiSDRs. To achieve internet sharing, the KiwiSDR runs a modified version of András Retzler’s OpenWebRX software. OpenWebRX is similar to WebSDR, but is open source and freely available to download online. The standard OpenWebRX is also designed to support the RTL-SDR. Of course if you don’t want to share your receiver over the internet you don’t have to, and you could use it on your own local network only.

Some applications of the KiwiSDR might include things like: setting up a remote receiver in a good noise free location, helping hams give themselves propagation reports by accessing a remote KiwiSDR while they are TXing, listening to shortwave stations, monitoring WSPR or WEFAX channels, education, crowd sourced science experiments and more.

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KiwiSDR Massdrop: $50 Saving on the Retail Price

The KiwiSDR is a wideband HF software defined radio that is designed to receive the entire 10 kHz – 30 MHz spectrum all at once. It works together with a BeagleBone single board computer and uploads it’s wideband radio data to the internet via the OpenWebRX SDR web interface and control software. Examples of KiwiSDRs shared publicly on the web with OpenWebRX can be found at sdr.hu.

Back in April of last year the KiwiSDR was successfully crowd funded on Kickstarter, and was later released for general ordering in October from SeeedStudio. Normally the KiwiSDR kit including KiwiSDR, BeagleBone, enclsoure, GPS antenna and SD card costs $299 USD.

Currently a Massdrop is underway for KiwiSDR (it seems that the link only works for logged in users). If you didn’t already know, a Massdrop is an organized group buy effort. Buy grouping several individual orders together and making a bulk order, the manufacturer is likely to give a discount. Currently the price for the KiwiSDR kit on the Massdrop is $249.99 USD ($50 saving on the regular price), with only 2 days remaining to join in. Once finished, the estimated shipping date is April 24, 2017.

The KiwiSDR
The KiwiSDR

KiwiSDR Soon to Accept General Orders

Back in April 2016 the KiwiSDR was successfully funded on Kickstarter. Since then almost all the rewards have been mailed out and the number of worldwide receivers available on sdr.hu has increased. KiwiSDR is an SDR cape (add on) for the BeagleBone Black/Green embedded computer which covers 0 – 30 MHz with 30 MHz bandwidth. It’s main purpose is to be used as a web based remote receiver which can be publicly accessed by many users.

Over on the Kickstarter updates page we see news that Seeed Studio is taking over the production and distribution of the KiwiSDR, and soon you’ll be able to order the KiwiSDR cape directly from their online Bazaar. Seeed studio is the same company that produces several other capes for the BeagleBone and they also produce the BeagleBone Green which is needed to run the KiwiSDR. They write:

We are very pleased to announce an agreement for Seeed Studio to take over production and distribution of the KiwiSDR going forward. What does this mean? Until now Seeed only had a contract with us to produce the Kickstarter rewards and pre-orders. Now Seeed will add the KiwiSDR to their family of BeagleBone capes they manufacture and distribute. Very soon you’ll be able to order the KiwiSDR directly from Seeed’s online Bazaar, pay directly with a credit card or Paypal and use their shipping system.

For us, and you as Kiwi owners, this is a very positive development. It means soon we’ll be able to devote the majority of our time to software development and providing you support. And as you probably know there is a large list of bugs, feature requests, extensions, distributed experiments and educational material we’d like to be working on instead of worrying about shipping and manufacturing issues. Improving the software is the best way to differentiate ourselves in a crowded SDR marketplace.

We would appreciate it if you would continue to purchase from us until our stock is depleted. Seeed has already manufactured a significant number of units alongside our prior build and will be able to meet the demand immediately. We thank everyone at Seeed for their fantastic effort in making KiwiSDR a reality.


KiwiSDR Kickstarter Successfully Funded

Last month KiwiSDR started their fundraising campaign on Kickstarter. The kickstarter has now completed. The goal was to raise $50,000 USD and they have well surpassed that mark by reaching $70,757 USD. If you missed out on the Kickstarter then it is still possible to preorder by directly emailing the KiwiSDR team.

The KiwiSDR is a software defined radio with 30 MHz of bandwidth and a tuning range that covers 0 – 30 MHz (VLF to HF). It is intended to be a low cost web based SDR that can be accessed from all over the world via a browser interface. It is designed as a cape for the BeagleBone Black mini embedded computer, and uses a LTC 14-bit 65 MHz ADC and Xilinx Artix-7 A35 FPGA. It 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. It runs on the OpenwebRX web based software, which many RTL-SDR users have already been using to stream live radio to the web.

Right now the team is beta testing some sample boards and appears to be getting ready for the large production run.

In a previous post we mentioned that the KiwiSDR project had some ethical issues attached to it. The creator of the OpenWebRX software, Andreas, was upset over the fact that the KiwiSDR had forked his open source project and had said that they would not share any profits. However, it appears that KiwiSDR have now struck a deal with Andreas, with both sides being happy, thus resolving any ethical issues.

The latest KiwiSDR Board
The latest KiwiSDR Board

Working Towards a Fast OpenWebRX HF Web Receiver + The Ethics of KiwiSDR

Over on his blog András Retzler has created a post that discusses his research work on creating a fast networked wideband HF receiver. András is the creator of the web based OpenwebRX software, which allows RTL-SDR and some other SDR’s to efficiently broadcast their SDR data over a network and onto the internet. Some live SDR’s can be found at the OpenWebRX directory at sdr.hu.

The problem with the current implementation, András writes, is that while OpenWebRX works well with the RTL-SDR’s 2.4 MSPS sampling rate, it can not work so well with very high sampling rates, such as 60MSPS due to excessive computational requirements when several channels need to be monitored. András’ solution is to use his Fast Digital Down Conversion (FastDDC) algorithm which is significantly more CPU efficient. András writes that the FastDDC algorithm improves computation by up to 300% in some cases, can speed up calculations on low powered computers like the Raspberry Pi 2 and can be implemented on a GPGPU for even higher performance. He is still working to implement the algorithm in OpenWebRX.

Performance of the FastDDC Algorithm
Performance of the FastDDC Algorithm

In addition to his work, András has also posted about what he feels is a bit of an injustice between his work on OpenWebRX and the KiwiSDR designers. The KiwiSDR is a new wideband HF SDR that has recently been successfully funded on Kickstarter. Andras writes that he is discontented with the fact that the KiwiSDR developers have forked his open source software (OpenWebRX) and are now profiting from it, without contributing back to the original project.  András writes:

John Seamons has forked OpenWebRX, and sells his own hardware with it. The web interface is clearly the selling point of the device. After getting a lot of help from me, most of which was inevitable for his success, now John and ValentF(x) are leaving me with nothing, except a ‘Thank you!’. John has told me that OpenWebRX is a large part of his project, and he also claimed that my work has reduced the time-to-market of his product by maybe a year or so.

Why I’m standing up here is that forking open source software (which means changing the code in a way that is incompatible with the original version, and taking development in another direction), and funding it through Kickstarter is a very unusual way of getting things done. I acknowledge that John has very much work in his board and the accompanying software, however, he treated me and my project in an unethical manner.

In the Kickstarter comments section, the KiwiSDR creators reply back with their side. It is hard to say who is in the right in a situation like this. While what KiwiSDR have done is legal according to the licence, the ethics of doing so are questionable. We hope that both parties can successfully come to an agreement in the end.

If you want to directly support András and his work on OpenWebRX and other projects like FastDDC, then please consider donating to him at http://blog.sdr.hu/support. If you are a KiwiSDR backer, donating to Andras may be one way to right the situation if a deal cannot be reached.

KiwiSDR: 30 MHz Bandwidth VLF to HF SDR now on KickStarter

Back on February 8 we posted about the up and coming KiwiSDR, a software defined radio with 30 MHz of bandwidth and a tuning range that covers 0 – 30 MHz (VLF to HF). It is intended to be a low cost web based SDR that can be accessed from all over the world via a browser interface. 

The KiwiSDR is designed as a cape for the BeagleBone Black mini embedded computer, and uses a LTC 14-bit 65 MHz ADC and Xilinx Artix-7 A35 FPGA. It 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. It runs on the OpenwebRX web based software, which many RTL-SDR users have already been using to stream live radio to the web.

Today the KiwiSDR started its crowd funding campaign on Kickstarter. A full KiwiSDR can be purchased for $199 USD, or for $299 including an enclosure, BeagleBone computer and GPS antenna. The fundraising goal is for $50,000 USD and if successful they estimate delivery in October 2016. The creators of the KiwiSDR write:

Sure, the world doesn’t really need another SDR. But we haven’t found one with this set of features. In cost and performance, KiwiSDR fits between RTL-SDR USB dongle-style, or fixed DDC chip devices ($20 – $400, 8-12 bit ADC, limited bandwidth), and full 16-bit SDRs ($700 – $3500) while offering better wide-band, web-enabled capabilities than the more expensive SDRs.

Our main motivation is to enable new applications which utilize a significant number of programmable, web-accessible SDRs world-wide. Direction finding remains one of the great under-solved problems of shortwave listening, particularly for utility stations. Given the GPS timing available on the KiwiSDR, could time-of-arrival techniques between cooperating SDRs be used? We’d sure like to find out.

Also, we’d like to see data decoders built directly into the web interface of KiwiSDR. There are many standalone programs that demodulate and decode data signals from SDRs. But these are computer- and OS-specific and often require a complicated interface to the data stream from the SDR. For example, we have a prototype of a WSPR decoder that is integrated into the KiwiSDR interface.

There are currently three KiwiSDR servers running publicly at the moment, and they can be accessed at:


The KiwiSDR Prototype
The KiwiSDR Prototype
KiwiSDR Running on OpenWebRX. Full 0 - 30 MHz spectrum.
KiwiSDR Running on OpenWebRX. Full 0 – 30 MHz spectrum.


KiwiSDR: 30 MHz Bandwidth SDR for VLF/LF/MF/HF

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:


The KiwiSDR
The KiwiSDR
KiwiSDR running on OpenWebRX.
KiwiSDR running on OpenWebRX.