Making Amature Radio Connections


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I have a new radio. I picked up a KiwiSDR (http://kiwisdr.com/) receiver from Seeed. (https://www.seeedstudio.com/KiwiSDR-Kit-p-2725.html).

The KiwiSDR was developed by the Funkamateur John Seamons ZL / KF6VO, is a branch of the OpenWebSDR project and realy started life as a kickstarter project.

This is the best HF (10kz-30mz) receiver I own. With the propagation so bad (its 2017) hams are using web based SDR receivers to make contacts. I share my SDR because I use other’s SDRs. Check out the list at (http://sdr.hu).

There a a couple of web based SDR servers out. The first I found was WebSDR.org. This is a sound card based SDR. Meaning, It receives left and right chanles as the quaditure IQ data from the sound card. This limits the band width the software can receive. To receive RF, most people use a down converter like the SoftRock (fivedash.com) tuned to the band they want to receive and feed the output the the sound card. With multipule receivers and sound cards WdbSDR can supply multipule bands to the web. Also you could downconvert any band.

I have two softrock receivers and the software for the WebSDR and I’m working on them. The KiwiSDR is up and running now. Why? Because it came out of the box working. It’s 100% plug and play.

I think I like the KiwiSDR more than the Websdr because it is fully open source. Both the hardware (https://github.com/jks-prv/KiwiSDR_PCB/tree/master/KiwiSDR) and software (https://github.com/jks-prv/Beagle_SDR_GPS) are avaible. So you could build your own or modify it for your needs. The web interface is written in Python. All you realy need to do is plug it in (power, antenna, network) and connect to it with a browser (Not IE). It boots into you’re wired network via DHCP.

I’ll be looping the my house to make a wire loop antenna for it. For now is has a 100 foot long wire attached.

Technical data:

  • Frequency range: 10KHz - 30MHz
  • Operating modes: AM, AMn, LSB, USB, CW, CWn, NBFM
  • Bandwidth filter: Adjustable between 50Hz - 10KHz
  • 30MHz low pass filter
  • 14bit ADC with 65MHz clock frequency
  • SMA RF antenna connection
  • 3.3V SMA connector for GPS active antenna

There are several places to purchase the KiwiSDR if you are intersted.

You can purchase a KiwiSDR here. SeeedStudio

UPDATE: 2022 New Update. The FlyDog SDR DIED! I’ve replaced it with a second KiwiSDR and now a Hermes Light2.

2016 I’ve added a new SDR. The FlyDog SDR is use the KiwiSDR software with new hardware arunning on a RasberryPi 3.

Tradition is… Amature Radio Operators don’t get along with each other’s projects. Witness APRS.

As the KiwiSDR source code is open source and itself boarrowed from OpenWebRX, it could be considered fair game to fork.The KiwiSDR developers don’t quite see it that way. John Seamons (ZL/KF6VO), the leader of the KiwiSDR project has announced that despite the clones KiwiSDR development will remain 100% open source with any future updates also being available to the cloners should they choose to implement them. He also mentioned to us that the clones will also be able to contribute to the TDoA service and can be listed on the KiwiSDR (http://kiwisdr.com/public/) directory. However, the reverse proxy feature will be limited only for official products. (Research needed here.)



M17 is a digital radio modulation mode, like DMR, D-Star, or Fusion, developed by Wojciech Kaczmarski (SP5WWP) in 2019. Unlike other protocols, M17 has every part of the protocol open source. See: M17Project.org.

OpenRTX is an open-source project used to replace the firmware in commercial amateur radios. See: OpenRTX.org.

OpenHT is a hardware project working to build and Open Hardware Handy Talkie. It is based on FPGA design - a complete Lattice Radiant project for the LIFCL-40-7SG72C.

Because I enjoy building electronics and support open-source projects, I have started working with these projects. I’d like to build and deply a M17 repeater in my area.

The M17 protocol is designed to be used with radios having 4800 symbols per second 4FSK with a root Nyquist filter applied to the bitstream. Radio channels are 9 kHz wide, with channel spacing of 12.5 kHz. The gross data rate is 9600 bits per second, with the actual data transfer at 3200.

I’ve build the following hardware:

** Module 17 is a smart-mic hardware M17 implementation running OpenRTX firmware. ** TYT MD390 with the OpenRTX firmware and a small hardware mod can be used with the M17 Protocol. ** MMDVM_HS hotspots running the latest MMDVM_HS firmware.

And, I’m doing my best to help with the OpenHT project.

More to come!