About KiwiSDR radios

Go to kiwisdr.com to learn all about these amazing little self-contained worldwide Internet-accessible radios that are made here in New Zealand.

They are shipped ready to plug and play. No other computer is required. Just plug in a 5V power supply, an Ethernet cable to your network, and an HF antenna and it will be accessible from anywhere in the world from the Internet. 

They are designed,  and supported by John Seamons, a ham radio operator (ZL4VO/KF6VO) who lives in New Zealand.

Finally, after two years of not having any KiwiSDR radios for sale due to global parts shortages, we are ready to start production of the new KiwiSDR 2. To have better control we have moved production from China to our home country (New Zealand) and started shipping in Dec 2023.

Unfortunately the cost of some of the key parts have gone up dramatically and also manufacturing locally is more expensive than making them in China. 

In addition to purchasing a KiwiSDR of your own you can use any web browser to connect and listen to over 800 of these radios all over the world. They have been made available by their owners for public access, see rx.kiwisdr.com  and map.kiwisdr.com They tune from 0-30 MHz and can receive and decode many signals including:

  • Amateur radio AM, FM, USB and LSB voice signals around the world.
  • Decode amateur radio FT4, FT8 and WSPR digital signals and CW (Morse).
  • Decode and display weather FAX signals.
  • Medium, Long Wave and Very Low Frequency (VLF) stations.
  • Shortwave international broadcast stations.
  • DRM (Digital Radio Mondial) digital broadcast decoding.
  • International airline traffic direct from the cockpit and control tower during flight (HFDL).
  • Long distance 27 MHz CB  operators.
  • Other stuff like some rather suspicious numbers stations.

See screenshots of the user interface and signal decoders here: KiwiSDR Github

The KiwiSDR displays the signals as a spectrum scope and waterfall. Using any computer you can click on a signal and listen to the audio anywhere without needing your own antenna and radio.

Many hams use the KiwiSDR radios to see if their signal is reaching another country and also to check their audio quality. Some hams who have very noisy home locations have found that they can transmit from their home but listen to the other stations on a KiwiSDR.

Here in NZ there is a system run by amateur radio operators where trampers (hikers) who go into remote areas can rent a very small low power HF radio called a Mountain Radio. Each evening the hikers can unroll the wire antenna and check in with the duty radio operator to report their location and request assistance in case of delays or need for rescue. The Mountain radios are only a few watts. The hikers can easily hear the 100W transmitter of the base station but the base often struggles to hear the hikers. The base station operators now use several different KiiwSDRs across the country to better receive the hikers.

Each KiwiSDR allows four people to connect at the same time and tune to different frequencies. Some owners of these "Kiwis" have three or four Kiwis connected to a single good quality antenna so those locations can have 12 or 16 people connected at the same time.

One of the best KiwiSDR sites in our part of the world is the Ironstone Range setup out of Adelaide, Australia. It is run by Paul Hoffman VK5PH. He has Kiwis connected to  a large duoconical wire antenna at a very quiet remote solar powered site with a radio Internet link. The duoconical is considered to be one of the best omnidirectional wideband HF antennas but they do need a lot of real estate.

We hope this project will bring you hours of listening pleasure and if you are not a ham radio operator we hope you might even get interested in becoming one  :-)

The final assembly, programming, testing and shipping is done in Masterton by another ham, David Bray ZL2BA. 

A local ham, John Futter ZL2TUD is an RF design engineer. He is designing an antenna amplifier/splitter for those who want to have more than one Kiwi on a single antenna. The splitter will also have switchable filters for those who are very close to high power AM stations which can cause overload. We will offer these for sale in this online store.

The new KiwiSDR 2 has a custom designed aluminium enclosure with good ventilation so no fan is required other than under extremely hot conditions. There are a large number of holes top and bottom so it would be easy to add a small external fan if desired.

The KiwiSDR needs a low noise 5V 1A supply for best performance.  The KiwiSDR draws about 700mA when running but on startup the BeagleBone draws a short high current pulse up to 2A. Many supplies do not deliver enough burst current which causes the BeagleBone power protection to disconnect from the supply.

Our tests have shown that the original Apple 5V 1A and 2A USB chargers that were supplied with every iPhone and iPad for many years will deliver the initial burst current and are also very low noise power supplies. Even if you have never owned an IPhone, plenty of your friends will  have one or more of these chargers laying around. Ask them nicely if they will sell you one and they might even give it to you for free :-)  Most  Apple clone chargers are very noisy so be sure that you only use a genuine Apple supply. You can buy an optional USB to 5V cable from our store when you buy your Kiwi. 

73 Peter Munn ZL2LD



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