Tagged: amateur radio

Maverick-603: An Affordable FT8 Receiver with an Open Source RF Chip

The Maverick-603 is a US$149 FT8 receiver based on an open source RF chip design which is capable of acquiring signals between 7 MHz and 70 MHz (technically 1 MHz to 100 MHz). It is currently undergoing Crowd Funding on Crowd Supply with 7 days left in the campaign. Shipping is expected to begin in April 2023.

FT8 is a popular weak signal propagation digital mode used by ham radio enthusiasts. FT8 signals can be received and decoded all over the world even with low transmit power and poor propagation conditions thanks to its highly error tolerant encoding. A dedicated FT8 receiver allows enthusiasts to set up a 24/7 FT8 monitor without dedicating more expensive ham radio equipment to the task. Note that a computing device like a PC or possibly a Raspberry Pi 4 will still be required to run the FT8 decoding software as this is a software defined radio.

The Maverick-603 is based on a custom open source RF chip design made possible by the company eFabless. It is now possible to cheaply design and produce custom ASIC chips (at least at the lower end of the technology scale), replacing more costly FPGA designs. The technical specs of the Maverick-603 are:

  • MCU: ATMEGA1608
  • Power Supply: 3.3 V / 10 mA
  • Operating Frequency Range: 1 to 100 MHz
  • Minimum Signal Strength: -25 dBm
  • Input Antenna Impedance: 50 Ohm
  • Data Interface: SPI
  • Board Size: 2" x 1.75"
  • Capable of receiving FT8 signals
  • 7 - 70 MHZ frequency range
  • Low-power operation (1.8 Volts) means no battery or outlet is required
  • USB Connection
  • A compact surface area
The Maverick-603 FT8 Receiver
The Maverick-603 FT8 Receiver

Internet Archive Seeks Donations of Materials to Build a Digital Library of Amateur Radio and Communications

In Internet Archive is a non-profit project with the main goal of maintaining a historical archive of the world wide web. Its goal is to preserve human knowledge and culture by creating an Internet library for researchers, historians, and scholars. Readers may be most familiar with their 'wayback machine', that allows users to view websites as they appeared in the past.

As part of this project, the Internet Archive is currently seeking donations of materials including printed medium relating to amateur radio and communications to add to their archives. Their press release and contact details read:

Internet Archive has begun gathering content for the Digital Library of Amateur Radio and Communications (DLARC), which will be a massive online library of materials and collections related to amateur radio and early digital communications. The DLARC is funded by a significant grant from the Amateur Radio Digital Communications (ARDC), a private foundation, to create a digital library that documents, preserves, and provides open access to the history of this community.

The library will be a free online resource that combines archived digitized print materials, born-digital content, websites, oral histories, personal collections, and other related records and publications. The goals of the DLARC are to document the history of amateur radio and to provide freely available educational resources for researchers, students, and the general public. This innovative project includes:

  • A program to digitize print materials, such as newsletters, journals, books, pamphlets, physical ephemera, and other records from both institutions, groups, and individuals.
  • A digital archiving program to archive, curate, and provide access to “born-digital” materials, such as digital photos, websites, videos, and podcasts.
  • A personal archiving campaign to ensure the preservation and future access of both print and digital archives of notable individuals and stakeholders in the amateur radio community.
  • Conducting oral history interviews with key members of the community. 
  • Preservation of all physical and print collections donated to the Internet Archive.

The DLARC project is looking for partners and contributors with troves of ham radio, amateur radio, and early digital communications related books, magazines, documents, catalogs, manuals, videos, software, personal archives, and other historical records collections, no matter how big or small. In addition to physical material to digitize, we are looking for podcasts, newsletters, video channels, and other digital content that can enrich the DLARC collections. Internet Archive will work directly with groups, publishers, clubs, individuals, and others to ensure the archiving and perpetual access of contributed collections, their physical preservation, their digitization, and their online availability and promotion for use in research, education, and historical documentation. All collections in this digital library will be universally accessible to any user and there will be a customized access and discovery portal with special features for research and educational uses.

We are extremely grateful to ARDC for funding this project and are very excited to work with this community to explore a multi-format digital library that documents and ensures access to the history of a specific, noteworthy community. Anyone with material to contribute to the DLARC library, questions about the project, or interest in similar digital library building projects for other professional communities, please contact:

Kay Savetz, K6KJN
Program Manager, Special Collections
[email protected]
Twitter: @KaySavetz 

SignalsEverywhere: Playing Classic Games over Amateur Radio with NPR-70 TCP/IP Modems

Over on her YouTube channel SignalsEverywhere, Sarah has uploaded a new video that shows us how TCP/IP connections can be made over the amateur radio spectrum using low cost NPR-70 TCP/IP modems that operate in the 70cm amateur band at around 433 MHz.

With a TCP/IP connection available it is then possible to play games over the amateur radio bands and Sarah demonstrates this in action with some classic games like Unreal Tournament 2004, noting that the ping was about 225ms. She notes that she used a lower symbol rate to keep within the legal limits within the USA, however in other regions a higher symbol rate may be possible, resulting in better ping. She goes on to try a strategy game called OpenRA which is a bit more suited to running on low speed high latency networks, noting that the radio TCP/IP connection worked very well.

In the video Sarah also shows what the modem signal looks like on the spectrum and waterfall using SDR++.

Playing Classic Games over Amateur Radio | NPR-70 Modem TCP/IP Unreal Tournament and OpenRA

Talks and Poster Presentations from the HamSCI 2021 Virtual Workshop

HamSCI is an organization dedicated citizen radio science and specifically the "publicity and promotion of projects that advance scientific research and understanding through amateur radio activities". Back in March they held their HamSCI 2021 workshop online, and the videos from presentations and posters are now all available on the Ham Radio 2.0 YouTube channel.

Most of he presentation videos were released back in June, but the poster talks were just released in the past few days. Many of the projects mentioned in the talks involve the use of software defined radios.

The talks include multiple presentations on the HamSCI personal space weather station project, updates on the TangerineSDR and lots of ionosphere research.

HamSCI 2021: iPoster Breakout Room 1

Using an RTL-SDR as a Panadapter with an Automatic Antenna Switcher

Over on YouTube "Gadget Talk" has uploaded a useful video showing how he set up an RTL-SDR V3 based panadapter system to use with his traditional amateur radio. The setup involves utilizing an antenna switcher which allows him to transmit with the RTL-SDR connected to the same antenna. The switch grounds the SDR during transmission, ensuring that the RTL-SDR is not overloaded with the transmit signal.

In the video he also shows how to set up the HDSDR receiver software and the HRD Rig Control software for controlling the hardware radio through the software and vice versa.

SDR Panadapter Using an Antenna Switcher

Setting up a Raspberry Pi for Ham Radio with RTL-SDR

Over on his blog F4GOH has posted a rather comprehensive tutorial consisting of seven PDF documents showing how he's set up his Raspberry Pi for ham radio and other RF projects. The PDF's essentially form a book that starts with the very basics like preparing an OS for the Pi SD Card, powering on the Pi, finding the IP address and connecting to it with SSH or VNC.

The tutorials move on to installing and using various ham radio programs like Fldigi, WSJT-X , GQRX, GNU Radio, before going on to teach some more Linux concepts. The final two PDF tutorials cover the installation and use of OpenWebRX for remote RTL-SDR use, R2Cloud for decoding weather satellites, and finally Radiosonde Auto RX for decoding radiosonde's on weather balloons.

[Also seen on Hackaday]

Raspberry Pi for Ham Radio

The Silphase R1 SDR Receiver

Thanks to Thomas' SWLing Blog for bringing to attention the Silphase R1 SDR receiver. This is an upcoming high performance HF SDR receiver being manufactured in the EU by a Polish company called Silphase. The R1 appears to be targeting premium SWLer customers with a price of US$1199. However, they note that by the end of 2020 they will have a 25W transceiver option, and later a 100W transceiver option. The SDR is currently available for preorder only and the sign up form can be found at the bottom of their website.

The Silphase R1 comes with a 5" touch screen that shows a spectrum display, has dual VFO's, four speakers and a metal alloy enclosure. It also comes with a built in telescopic antenna, but external antennas can be connected with the F connector. The tuning range is just the HF bands from 0.1 - 30 MHz and the ADC resolution is 16 bits.

Rendering of the upcoming Silphase R1 HF SWLing SDR

TechMinds: Building a 3D Printed 2.4 GHz Dual Feed Helix for QO-100

The Bullseye LNB that we have in our store is great for receiving the QO-100 amateur geostationary radio satellite which is available in some parts of the world. However it cannot be used to transmit to the satellite. Over on his YouTube channel Tech Minds shows us how to build a transmit helix antenna that connects to the Bullseye or other suitable LNB, resulting in a dual feed antenna.

The antenna that was built is based on DO8PAT's "Ice Cone Feed" design. The design requires some 3D printed parts for the mount and housing, as well as a copper wire helix, metal reflector and copper matching strip. The Bullseye fits onto the back of the helix mount. Once mounted on a dish Tech Minds shows that he was able to make contact with a friend via the QO-100 satellite with good signal strength.

2.4 GHz Dual Feed Helix Antenna For QO100