Updated 2023-03-17
This web page is an adjunct to the Zero Retries newsletter, specifically Zero Retries 0090 published 2023-03-17.
Some items span more than one category, but for economy of space, I’ll (usually) list an item once in the category that (in my opinion) fits most closely. I suggest you read the following references as mentally prepending the title as “If you’re interested in X, then check out these Ys”.
This list is but a smattering of just how much technical innovation IS occurring in Amateur Radio. And yet, you will only read about a “smattering of this smattering” in the “Amateur Radio Publishing Industrial Complex”, and I don’t just mean the two leading US Amateur Radio magazines. To a great extent, the Amateur Radio YouTube hosts are just as guilty of not showcasing the breadth of technological innovation that is occurring. It’s maddening to see “innovation” reduced to the newest, shiniest HF radio, or portable, or ? To me, what is most encouraging about Amateur Radio innovation is the totality of the technological innovation that’s occurring.
Zero Retries is just one voice in Amateur Radio, operating with no budget, with one writer. You’d think there would be more, and better funded such efforts. I agree that there should be.
This page should not be considered comprehensive, and lack of inclusion here should not be considered as lack of endorsement as “Zero Retries Interesting”. Much good stuff was not included simply due to limited space. Apologies in advance for terse / incomplete descriptions - see the links for detail.
None of these listings have been extensively vetted; some are undoubtedly "abandonware", and I'm sure at least a few of these websites are no longer functional.
Many of these items have been discussed previously in Zero Retries - just Search Zero Retries.
New additions or significant updates from the previous version of this Omnibus are prepended with New0090 - just search for that if you want to quickly find the new or updated items.
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Amateur Radio Bands of Interest
I've mostly been a fan of the Amateur Radio Very High Frequency (VHF) and Ultra High Frequency (UHF) bands, rather than the Amateur Radio High Frequency and Microwave (above 1 GHz) bands. Being in the US, I'm subject to, and benefit from, the allocations of Amateur Radio bands from the Federal Communications Commission (FCC). Other countries' Amateur Radio allocations are different. The American Radio Relay League (ARRL) has a nice page with US Amateur Radio allocations in text rather than hard-to-read poster form. The bands of most interest to me, and why. Links are to the relevant Wikipedia articles:
- 28.00 - 29.70 MHz (10 meter band) - This band is underutilized by most Amateur Radio operators, but reasonable speed data. It offers some interesting propagation randomness, especially in the summer.
- 50.00 - 54.00 MHz (6 meter band) - Like the 10 meter band, this band is underutilized and can do data, and offers interesting propagation randomness.
- 144.00 - 148.00 MHz (2 meter band) - The 2 meter band is the most popular VHF / UHF band. If offers good range (within Line of Sight Limitations). It was the most commonly used band for packet radio - 145.01 MHz was the original packet radio frequency, and 144.39 is used very extensively for Automatic Packet Reporting System (APRS).
- 219.00 - 220.00 MHz (1.25 meter band) - The 219-220 MHz band was allocated to secondary Amateur Radio usage when 220-222 MHz was reallocated. Its arcane usage rules means that it's never been used (to my knowlege) and there's no activity (to my knowlege) to change that status.
- 222.00 - 225.00 MHz (1.25 meter band) - The 222-225 MHz band in the US is underused. It's an ideal "playground" for data communications, but is hampered by few 222-225 MHz radios currently in production (see below).
- 420.00 - 450.00 MHz (70 centimeter band) - Most of the US is blessed with 30 MHz of spectrum in the 70 centimeter band. Those of us unfortunate enough to live within approximately 75 miles of the Canada / US border (Line A) cannot use 420.00 - 430.00 MHz as that portion is allocated to commercial use in Canada. The 70 centimeter band is used extensively for higher speed / higher bandwidth communications. For example, it's acceptable in the FCC rules to use a 100 kHz channel within the 70 centimeter band.
- 902.00 - 928.00 MHz (33 centimeter band) - The 33 centimeter band is one of the most interesting US Amateur Radio bands. It overlaps 100% with the Industrial, Scientific, and Medical (ISM) rules, meaning that there's no "exclusive" Amateur Radio operation in this band. There are licensed services within 902 - 928 MHz but those licensed services cannot require the license-exempt (ISM) users to cease and desist, and must accept any interference from licens-exempt users. In my opinion, 902-928 MHz is most useful from technologically sophisticated ISM devices such as those from Freewave Technologies and other vendors.
- 1240 -1300 MHz (23 centimeter band) - The 1240-1300 MHz band in the US is underused. It's an ideal "playground" for wideband data communications, but is hampered by only two commercial Amateur Radios for this band - the Icom IC-9700 and the Alinco DJ-G7T portable.
- 5.850 - 5.925 GHz - This band is particularly useful because it's not until recently it wasn't shared with unlicensed ("Part 15") usage, thus it's comparatively "quiet". While this band is allocated for Amateur Radio use in the US, in other parts of the world it's just another unlicensed band so units for broadband wireless are readily available. To buy such equipment in the US usually requires a letter of justification and proof of Amateur Radio license.
- 10.0 - 10.5 GHz - This band just got a lot more interesting with the announcement of the Icom IC-905 which includes (optional) 10 GHz capability.
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Amateur Radio Digital Communications (ARDC) Grants
These are some of my favorite Zero Retries Interesting grants from ARDC that have been publicly announced as of 2023-03-17 (Zero Retries 0090). These will be terse as ARDC is awarding a lot of grants. Many of these are great examples of projects that could only be funded by a foundation with considerable resources... and vision... such as ARDC that can see the value of investing in Amateur Radio (and related fields).
Disclaimer - in 2021 and 2022, I was a volunteer on the ARDC Grants Advisory Committee and these mentions are solely my own perspective - I'm not speaking for or representing ARDC; nor does ARDC represent or speak for me. All information below is public.
ARISS-USA Program - A multi-year grant to fund operations and new iniatives.
ARISS Next Generation Radio - New Amateur Radio systems on the International Space Station.
Building a Wireless Backbone in the High Sierras - Amateur Radio microwave network.
Central Michigan Emergency Network Mi6 WAN Project - Amateur Radio microwave network.
DAEmod-915: Open-Source Open-Hardware 915MHz Digital Transceiver - Development of a new Open Source Amateur Radio 902-928 MHz radio.
Develop a 3U Open Source CubeSat Space Frame With Deployable Solar Panels - Deployable solar panels on an Amateur Radio satellite seem like a significant increase in capability.
Digital HF Telecommunications for Civil and Amateur Uses - Using HF for data communications in areas that have no communications infrastructure.
DSES Facility Upgrade - Adding new capabilities to an amateur radio astronomy and Amateur Radio experimentation facility.
Enhanced, Scalable Repeater for Emergency Communications - Amateur Radio microwave network, notable for use of 10 GHz band.
New0090 Enhancing HF Digital Voice with FreeDV - Improvements to FreeDV including speech quality and low(er) signal-to-noise operation.
Expanding Multi-state, 5 GHz Microwave Network in Rockies and Outfitting Communication Trailers - Amateur Radio microwave network.
Expansion and Equipment Upgrade for The AggieSat Laboratory - Space laboratory at Texas A&M University.
Fixing the Linux kernel AX.25 - This has been an issue for some time, and finally resources are being allocated to update it.
GNU Radio Project (2020) - GNU Radio Project is an amazing resource!
GNU Radio Usability Enhancements - Updating GNU Radio to be easier to use, better support in Windows, and better documentation and maintenance.
Independent 5GHz Backbone IP Network for Public Amateur Radio Services in Finland - Amateur Radio microwave network.
Low-Cost Open-Source Universal Radio Test Instrument, A - Open source project from Great Scott Gadgets to create a unit that incorporates
- spectrum analyzer
- vector network analyzer
- vector signal generator
- vector signal analyzer
- antenna analyzer
- power meter
- frequency counter
- full-duplex SDR transceiver
M17 Open Protocol - This grant really "kickstarted" M17 Project to be able to make significant progress.
Maine Ham Radio Mesh Network - Amateur Radio Microwave Network using AREDN technology.
MIT Radio Society Radome Renewal - To date, this is my favorite ARDC grant, mostly because the scope was audacious and something only ARDC could have done, and it enabled some really, really bright people with new capabilities. The Boston Globe did a nice article about this project.
National VOA Museum STEM Lab Expansion - Introducing STEM / physics subjects at Voice of America (VOA) Museum of Broadcasting.
NRAO – Why Ham Radio Matters - Introducing Amateur Radio to youth of under-represented groups under the auspices of National Radio Astronomy Observatory (NRAO).
NTPSec - A (more) secure version of (Internet) Network Time Protocol (NTP).
Oregon HamWAN Backbone Project 2021 - Amateur Radio microwave network.
San Francisco (SF) Emergency Wireless Mesh - A larger, improved non-commercial / Amateur Radio wireless mesh network in the San Francisco Bay Area.
Student ARRL / TAPR DCC Attendance - Helped fun students attending the 2019 ARRL and TAPR Digital Communications Conference.
Support and development of the SondeHub platform - Display of radiosondes, including those that have been recovered and repurposed for Amateur Radio use.
Support for North Bay Area Mesh - Amateur Radio microwave network.
TangerineSDR Project Advancement - Development of a new Open Source HF Software Defined Radio.
TangerineSDR Test Fixtures - Development of a new Open Source HF Software Defined Radio.
Wireless Regional Area Network in Sub-GHz Bands as Last Mile for HAMNET - Development of a new Open Source 50 MHz / 144 MHz / 440 MHz Software Defined Radio.
ARDC has funded many scholarships, communications trailers, and club stations, including numerous college Amateur Radio stations.
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Awards / Recognition
Amateur Radio Software Award - “Promoting software projects that enhance and adhere to the spirit of amateur radio: innovative, free and open“.
ARRL Technical Awards - Annual awards from the ARRL for Technical Service, Technical Innovation, Microwave Development, and “Doug DeMaw W1FB Technical Excellence Award“.
Hamvention Awards - Annual awards from Dayton Amateur Radio Association (sponsor of Hamvention) for Special Achievement and Technical Achievement.
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Conferences / Events
AMSAT-DL Symposium - Amateur Radio satellite conference in Germany.
AMSAT-NA Space Symposium & Annual General Meeting - Amateur Radio satellite conference. Location rotates around the US / Canada.
AMSAT-UK Colloquim - Amateur Radio satellite conference. Location rotates around the UK.
DEFCON - Surprising amount of Amateur Radio at "one of the oldest, and largest, continuously running hacker conventions".
Digital Communications Conference (DCC) - This is the big one for technological innovation in Amateur Radio (don’t let the underwhelming web page fool you). This conference has been held for decades now and some of the most amazing developments in Amateur Radio were first revealed at DCC. Location rotates around the US / Canada.
GNURadio Conference (GRCon) - This is the big one for open source Software Defined Radio, with a healthy mention of Amateur Radio. Location rotates around the US / Canada.
Hackaday Superconference / Supercon - From the Hackaday folks, Pasadena, California, USA.
Ham Fair - Largest Amateur Radio conference in Asia - Tokyo, Japan.
Ham Radio (Friedrichshafen) - Largest Amateur Radio conference in Europe - Friedrichshafen, Germany.
Hamvention - Largest Amateur Radio conference in the USA - Xenia, Ohio, USA.
Hackers on Planet Earth (HOPE) - From the 2600 Magazine folks - New York City, New York, USA.
DEFCON - Radio technology is a big part of DEFCON, notably Ham Radio Village; Amateur Radio is attracting interest from hackers - Las Vegas, Nevada, USA.
MicroHAMS Digital Conference - Smaller version of DCC - Redmond, Washington, USA.
QSO Today Virtual Ham Expo - Amateur Radio conference with good presentations, virtual.
Small Satellite Conference - Logan, Utah, USA.
Utah Digital Communications Conference - Sandy, Utah, USA.
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Cost Is No Object
Ya gotta dream at times…
FlexRadio 6400M with Q5 Signal 5-Band High Power VHF/UHF Transverter - I told the story of this combination in The Ultimate Software Defined (Mostly Data) Radio in Zero Retries 0034. Combine with a self-supporting collapsible tower (for easy antenna work) and assorted antennas.
Fast Data - If I was ever offered a blank check to set up a cool, “high speed” data system for a small group of Amateur Radio Operators that wanted to have a data system that “just works, reasonably fast, pretty reliably”, these are the elements of a system I would build in 2022:
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Icom IC-9700 as user radios because it includes the 1240-1300 MHz band and “Digital Data Mode” - 128 kbps and an Ethernet Interface.
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With every IC-9700, a Raspberry Pi to handle the DD data (TCP/IP applications such as Post Office Protocol (POP) email, Simple Mail Transfer Protocol (SMTP) email, Bulletin Board System (BBS), File Transfer Protocol (FTP), web server, web client, etc.)
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Icom ID-RP1200VD 1240-1300 MHz D-Star Digital Voice (DV) / Digital Data (DD) Repeater, configured for DD Mode. (Last minute update - now I would suggest the not-quite-a-product Icom IC-905 radio which adds 2.4 GHz, 5.6 GHz, and 10 GHz.) Installed on a great site (high tower or mountaintop), probably commercial, with very low-loss hardline and a high-gain, robust antenna, and a power amplifier rated for 100 kHz channel (repeater output power is a mere 10 watts). Part of the blank check would be to fund ongoing expenses for this system to be on a commercial radio communications site.
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Digital Voice
Amateur Radio ThumbDV - Easiest method for experimenting with mostly-software approaches to Amateur Radio Digital Voice modes; incorporates the most common (hardware) CODEC in use in Amateur Radio. Attaching a ThumbDV to your network and a system such as AMBEserver allows encoding and decoding of digital voice.
Buster - App for Mac to access the D-STAR digital voice network from their Internet connected Mac.
Brandmeister is a independent network for linking Amateur Radio digital voice repeaters (mostly Digital Mobile Radio - DMR) via Internet. Brandmeister promotes open access and experimentation in repeater linking, including text messaging.
New0090 FreeDV - Open source, low-bitrate digital voice system optimized for use on HF.
IRCDDB - IRCDDB is the "non-official" network of D-Star repeaters; anything I do with D-Star will use IRCDDB.
M17 Project - My mental model for M17 Project a Digital Mobile Radio (DMR) re-implemented as open source, for Amateur Radio. M17 is implementing the protocol, networking, some data capability, and especially the use of the CODEC 2 open source digital voice encoder / decoder (CODEC).
Make Your Own MMDVM Repeater - Easy to follow instructions on the details needed to assemble a repeater that works with all digital voice modes with an MMDVM unit.
Multi Mode Digital Voice Modem (MMDVM) - Open source software to use of any / all digital (and some analog) voice modes for Amateur Radio. It can even be used to implement repeaters that will “pass through” any digital voice (or analog, such as FM) voice. MMDVM hardware is available from a number of vendors.
PiStar - “Software image for the Raspberry Pi to provide the complex services and configuration for Digial Voice on Amateur radio in a way that makes it easily accessable to anyone just starting out.“
RadioID.net - Worldwide, unified management of unique ID numbers for Amateur Radio use of Digital Mobile Radio (DMR).
Single Channel Repeater - Single Channel Repeaters have been done, but only as a "record for seconds, then play back for seconds. Instead of that, think receive for 5 mS, then transmit for 5 mS. Some commercial DMR repeaters implement this idea as one timeslot continuously receives, and the other timeslot continually transmits, using only a single 12.5 kHz channel.
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email via Amateur Radio
Winlink is the primary method of email via Amateur Radio because of its integrated handling of Internet email, provided software, and well-proven techniques, and a very wide ecosystem of organizations that use it, users, training, etc.
On HF, VARA HF and Pactor are the most common connection types. On VHF / UHF, 1200 bps AFSK packet radio is the most common connection type, but VARA FM is becoming common because of its speed (up to 25 kbps) and reliability (includes Forward Error Correction) advantage over packet radio. AREDN networks are also being configured to include a Winlink gateway.
PiGate makes it easy to set up a publicly accessible gateway that allows public users to send (emergency) email via Winlink, such as at a mass casualty shelter.
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Funding for Amateur Radio Interesting Projects
Amateur Radio Digital Communications (ARDC) is a private philanthropic foundation that provides grants in three broad areas:
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Support and growth of Amateur Radio
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Education
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Research and development
ARRL Foundation Amateur Radio Club Grants - funded for 2022 by a grant from ARDC.
Crowd Supply - Crowdfunding for technology projects, including radios such as KrakenSDR.
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HF Data Communications - Hardware, Software, Systems
New0090 - Automatic Link Establishment - Protocol for automatically establishing a link via HF radio.
BITX HF Radio Kits - Simplified HF radio kits, reasonable transmit power, and include multiple bands and SSB capability; good for data modes.
Fldigi - Suite of audio interface “Fast, Light Digital Modes” designed for HF. It's actively maintained and well documented. Some fldigi modes such as FSQ (Fast Simple QSO), are quite usable on VHF / UHF FM.
Hermes-Lite 2 - HF software defined radio.
JS8Call - One plaint about using the WSJT-X modes (see below) is that they’re designed for “no chat, just log it” contacts. JS8Call adapts the highly robust WSJT-X technologies for chatting, and also provides for APRS transmissions for position, status reports, email, phone-text messages, etc. that can be gatewayed into the APRS Internet backbone.
Networking Over HF - Interesting project!
QDX Digital HF Transceiver - 80, 40, 30, and 20 meter coverage @ 5 Watts output.
Q15X25 - Interesting HF data mode by Pawel Jalocha, SP9VRC. Designed to pass AX.25 packets on HF with speed and reliability much greater than traditional HF ARQ modems. It uses 15 QPSK modulated carriers separated by 125 Hertz, each modulated at 83.333 baud. Q15X25 uses forward error correction (FEC), and like MT63, uses time- and frequency-interleaving in order to avoid most error sources. The raw transmission data rate is typically 2500 bit/s.
RadioBerry V2.0 - HF Radio HAT for Raspberry Pi computers.
New0090 Rig-in-Box for DXPeditions (YouTube) - a sealed, self-contained remote controlled HF station for unattended operation on DXPedition locations where it's not appropriate for operators to be present to operate radios, camp, sleep, eat, etc. The heat exchange system alone is innovative.
Robust Packet - A project is underway to revive the Robust Packet on-air protocol.
Robust Packet Terminal Node Controller (TNC) - Zip file download of the project info.
TAPR WSPR HATs - Inexpensive boards (kits), plus a Raspberry Pi, plus a modest HF antenna are all you need to operate a WSPR transmitter (beacon). The 10-meter (28.0 - 29.7 MHz) version can be used with the US Technician class license, thus that is a great project for new Amateur Radio Operators - put your unit on the air and watch your signal be heard around the world.
VARA HF - High Performance HF modem using OFDM modulation. VARA Chat is a companion app from the author of VARA that provides chat and file transfers.
VarAC is a good chat / email / file transfer app built on top of the robust VARA HF and VARA FM modes.
WSJT-X Modes - If you have any doubt that Amateur Radio has entered into a brave new world where digital / data modes will dominate Amateur Radio, just experiment with some of the WSJT-X modes to see just how amazing radio technology really is.
ZachTek WSPR Desktop transmitter - Standalone WSPR transmitter - various models cover various bands.
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Interesting Projects In Development
“In development” is the operative phrase for items in this section; they’re in the process of being readied for full release, or in the pre-crowdfunding stage, etc.
New0090 All-In-One-Cable (AIOC) - A radio / computer interface using USB-C providing audio interface / push-totals circuit, and programming circuit. Prior to this project, the former and latter functions were separate units.
Codec 2 / FreeDV for HF Data Communications - Adaptation of the robust and spectrally efficient technology of Codec 2 / FreeDV (originally for digital voice) for text messaging and data.
Drift Buoy Telemetry - Interesting Project by Paul Elliott WB6CXC for a "drift buoy" and a telemetry package via Amateur Radio - presentation, ongoing development notes.
ezDV - Simple encoder / decoder for FreeDV using an ESP-32. Intro.
GroundSat - A concept (for which I could not find a definitive web page) of installing the equivalent of an Amateur Radio satellite linear transponder (such as uplink on 144 MHz and downlink on 420-450 MHz) on a terrestrial site such as a very high tower or mountaintop. This concept has been around for a long time, but (think…) I’ve seen recent (passing) references to it in Open Research Institute’s Phase 4 Ground Station and Phase 4 Space projects.
Halo TD-XPAH - (Overlaps with Amateur Radio) Crowdfunded (in progress) radio for 902-928 MHz based on 802.11ah and 802.11s.
New0090 hz.tools - Project by Paul Tagliamonte K3XEC to create his own Software Defined Radio stack and accompanying tutorial. Useful because of K3XEC's "single person perspective".
ka9q-radio - Project by Phil Karn KA9Q that “virtualizes” a single Software Defined Receiver into multiple instances of receiver modules that enables an entire VHF / UHF band to be monitored simultaneously through the use of IP multicasting.
Mini17 - Open Source QRP portable radio designed around M17.
New0090 Next Project, The - Project by Anthony Good K3NG to develop a 160m through 70cm radio.
New0090 Opulent Voice - High(er) quality digital voice (and data) when there is ample bandwidth (as opposed to minimal bandwidth available, such as on HF).
OreSat Ground Station - Handheld ground station for OreSat (Portland State University).
Packet Radio Users Group (PRUG) FX.25 KISS TNC - FX.25 to date has only been implemented in Dire Wolf software (needs a host like a Raspberry Pi and a sound card). An "appliance" like this could make FX.25 and Forward Error Correction more widely used.
Prototype Pi Teensy Micro v1.1 TNC - No further development noted, but it was a neat idea!
New0090 Project Yamhill - Project by Jason Milldrum NT7S to build an (HF?) radio with a modular architecture, including a physical substrate / backplane that can be 3D printed.
QO-100 TX - One example of the innovative projects that the QO-100 geosynchronous payload inspires - CW Transmitter with OLED Display using 2.4 GHz LoRa module with TCXO.
New0090 RFBitBanger - Project to develop a low power (QRP) HF radio that is easy to build and maintain. Will operate a new data mode called SCAMP which incorporates Forward Error Correction (FEC).
Rhizomatica High-frequency Emergency and Rural Multimedia Exchange System (HERMES) - Innovative built-from-scratch system that uses High Frequency (HF) radio as a backbone for exchanging email in very rural areas.
New0090 - Rhizomatica Mercury - A configurable open-source software-defined modem used in the HERMES system from Rhizomatica (see above) that incorporates Orthogonal Frequency Division Multiplexing (OFDM) techniques.
RPX-100 - Project by Austrian Amateur Radio Society (ÖVSV) to develop a 6 meter (50-54 MHz) / 2 meter (144-148 MHz) / 70 centimeter (440-450 MHz) radio based around a Software Defined Transceiver (LimeSDR Mini).
SOCORAD32 - Crowdfunded (in progress) hackable, open source ESP32 Amateur Radio board in portable form factor including voice and data.
Tangerine SDR - A project by TAPR to develop an HF Software Defined Transceiver with unique characteristics to support HamSCI.
VXSDR-20 - Crowdfunded (in progress) high performance Software Defined Transceiver covering 5-20 GHz.
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Media - Blogs
Advancing Ham Radio.. different ideas - Good blog of thoughts on Amateur Radio future.
Hackaday Radio Hacks - Features Amateur Radio as an enabling, useful technology for self-education about radio and wireless technology.
John's Geekblog - Time Nut Extraordinaire John Ackerman N8UR.
KB6NU's Ham Radio Blog - Often surfaces Zero Retries Interesting topics.
RTL-SDR Blog - In addition to selling software defined receivers, it’s a popular blog for news about software defined radio devices.
SuperPacket - This blog.
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Media - Books
ARRL Handbook 100th Edition - I helped update Chapter 15 - Digital Protocols and Modes.
Designing Electronics That Work - Great review by Dan Romanchik KB6NU.
New0090 Exploring Software Defined Radio (featuring Raspberry Pi Projects)
Ham Radio for Dummies - I gift this book to prospective and new Amateur Radio Operators in my circles; it’s a great overview.
Ham Radio’s Technical Culture - Dated and out of print, but still interesting.
Playing with Meteors - Good perspective of the how to learn about radio technology through hands-on Amateur Radio.
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New0090 Media - Classes / Tutorials
Getting Started with Radio Frequency Applications - Microchip University
ScratchRadio - Uses the Scratch visual programming language on Raspberry Pi to teach Software Defined Radio technology - Lime Microsystems.
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Media - email Mailing Lists
Over time, this list will be more comprehensive. There are so many interesting email lists.
aprssig - The primary discussion and support list for APRS activities.
AREDN - Amateur Radio Emergency Data Network.
D-STAR23cm - Operating Icom D-Star Digital Voice and high speed (128 kbps) data on 1240-1300 MHz (23 cm).
Digital-mode-radio - General discussions of Amateur Radio data modes.
direwolf - Discussion of the Dire Wolf Software TNC.
DRA - Discussion and support for the Masters Communications Digital Radio Adapters (DRA) products.
freedata - Discussion, support, and scheduling contacts for the freedata software that uses FreeDV as transport on HF.
g3ruh-modem - Discussion and support for connecting G3RUH modems to radios.
GEO - Discussion about potential Geosynchronous Earth Orbit satellite for the Americas.
HamSCI - Ham Radio Science Citizen Investigation (see Organizations).
ic-905 - Discussion of the (pending) Icom IC-905 radio.
linuxham - Discussion and support of the fldigi suite on Linux, UNIX, and MacOS.
mobilinkd - Discussion and support of Mobilinkd TNCs.
New Packet Radio - Discussion and support of New Packet Radio.
ninotnc - Discussion and support for TARPN NinoTNCs.
New0090 Radio Artisan - Experimentation and open source.
Raspberry-Pi_4_Ham-Radio - Wide ranging discussions about using Raspberry Pi in for Amateur Radio.
udrc - Discussion and support of Northwest Digital Radio UDRC.
VARA-MODEM - Discussion and support of the VARA series of software modems.
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Media - Magazines / Columns
73 Magazine - Complete run (1960 - 2003) of 73 Magazine is digitized and publicly available on the Internet Archive. There is also a great online index for 73 Magazine.
CQ-DATV - Click around on this page - all of the issues (1 - 100) are available in PDF somewhere.
Digital Connection - A multi-page column by Don Rotolo N2IRZ in CQ Magazine; always Zero Retries Interesting. To read Digital Connection requires (minimum) a $30 / year subscription (electronic only) to CQ Magazine.
Ham Radio Magazine - Complete run (1968 - 1990) of Ham Radio Magazine is digitized and publicly available on World Radio History. Despite its vintage, there's a lot of relevant info there. Ham Radio was the most technical of the four (at one time) Amateur Radio magazines in the US.
Ham Radio Horizons - Complete run (1977 - 1980) of Ham Radio Horizons is digitized and publicly available on World Radio History. Despite its vintage, there's still a lot of relevant info there.
On The Air Magazine - Digital (or print if you opt for printed version of OTA instead of QST) bimonthly non-technical publication magazine from ARRL for new Amateur Radio Operators. On The Air Magazine is a membership perk of ARRL membership. To read On The Air Magazine requires a $49 / year membership in ARRL ($25 / year for < 26 years old, but requires considerable effort to prove your age). OTAM is notable that it tries to explain Amateur Radio topics without resorting to Amateur Radio jargon.
QEX - Digital-only bimonthly technical publication from ARRL. QEX is a membership perk of ARRL membership. To read QEX requires a $49 / year membership in ARRL ($25 / year for < 26 years old, but requires considerable effort to prove your age).
Radio Shack Catalogs - 'nuff said :-)
The Communicator - Great "newsletterzine" by Surrey (British Columbia) Surrey Amateur Radio Communications (SARC). Good mix of articles including some Zero Retries Interesting.
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Media - Newsletters
ARRL Gateway - Newsletter about the evolution of Packet Radio; partial - 1985 - 1990 (missing 1984).
Amateur Radio Weekly - Weekly list of Amateur Radio stories, often some Zero Retries Interesting.
Experimental Radio News - Selected FCC Part 5 Experimental Licenses. Highly recommended - you’ll learn a lot.
Pacific Packet Radio Society - They were there in the beginning of the Packet Radio Revolution, including the very first AX.25 digipeater in the US.
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Media - Papers
A Brief Survey of Technological Innovation in Amateur Radio - Paper by N8GNJ for the 2022 ARRL and TAPR Digital Communications Conference (DCC)
Multipurpose Remote Nodes - Paper by KF7VOL and N8GNJ for the 2021 ARRL and TAPR Digital Communications Conference (DCC) - remotely configurable nodes for Winlink / APRS / fldigi (fsq) relay, and other modes.
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Media - Podcasts
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Media - Video - Documentaries
HAM - A documentary by a student filmmaker about a small number of Amateur Radio Operators in Montana, USA. Notable that it features Amateur Radio Operators in space, and a brief demonstration of Earth Moon Earth (EME) / Moonbounce communications.
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Media - Video - Tutorials
How to Make Meteor Scatter QSOs
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New0090 Media - Video - YouTube
HB9BLA Wireless by Andreas Spiess HB9BLA emphasizes data communications.
KM6LYW Radio by Craig Lamparter KM6LY emphasizes Amateur Radio data communications such as the DigiPi project.
Tech Minds by Matthew Miller M0DQW is subtitled Ham Radio - SDR - RF Projects - Software - Tutorials.
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Media - Websites
APRS.fi - Best known, highest traffic web page of APRS in action. Particularly useful for high altitude balloon flights, etc.
APRS.org - The “APRS Omnipedia” created by Bob Bruninga WB4APR (Silent Keyboard) and is the most comprehensive reference on APRS (at the moment).
Amateur Radio Digital Communications (ARDC) Grants Awarded - When a grant is awarded, a brief description is posted. No RSS - requires manual polling.
Broadcastify - Web feeds of two-way radio traffic, mostly public safety, but some Amateur Radio. In my opinion every Amateur Radio repeater ought to have a Broadcastify feed.
Digital Library of Amateur Radio & Communications (DLARC). This was funded by a grant from ARDC. It's making great progress with more than 30,000 items available as of this update.
Internet Archive - A source of historical Amateur Radio information including the complete run of 73 Magazine (see DLARC above).
Microwave Amateur Radio - Amateur Radio Microwave info.
Nationwide Amateur Radio Packet Directory.
OpenWebRX - “Multi-user SDR receiver that can be operated from any web browser.“
Packet-radio.net - Great reference site for all things Amateur Radio Packet Radio.
RadioReference.com - database of public safety frequencies and live audio feeds of public safety.
Receiverbook - Directory of receivers accessible online.
Repeater Builder - Omnipedia for building and maintaining repeaters.
RepeaterBook - Independent online directory and pocket computer apps of Amateur Radio and GMRS repeaters.
Robust Packet Network - Robust Packet Radio is a new mode that was previously only available on certain SCS modems, but is now being implemented on other devices.
Reverse Beacon Network - Worldwide network of receivers linked via Internet.
Signal Identification Guide - an open sourced (Wiki) compendium of various modulation types. When you receive something you don't understand, look it up here.
Signals Everywhere - Good reference site on using Software Defined Transceivers.
SondeHub - Interactive website displaying radiosonde (weather balloon) locations and data. Some radiosondes are used once and repurposed for Amateur Radio missions.
UHF-Satcom - (Amateur Radio adjacent) Satellites don’t just use microwave frequencies; good info for monitoring satellites that operate at UHF frequencies.
Weak Signal Propagation Reporter Network (WSPRNet) - Network of receivers that monitor for Weak Signal Joe Taylor - Experimentatal (WSJT-X) transmissions/
World Radio History - (Amateur Radio adjacent) Archive of technical and Amateur Radio magazines, including Popular Electronics, Radio Electronics, and many others.
(I’m very, very interested of hearing about other “media” that are Zero Retries Interesting - please let me know about any that are interesting to you in the same vein as Zero Retries.)
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Networking - Internet
44Net is an allocation of 12 Million IPv4 Internet Addresses dedicated to Amateur Radio experimentation and networking. One significant feature of 44Net is that Amateur Radio operators can be allocated static and routable IPv4 addresses. 44Net is administered by Amateur Radio Digital Communications (ARDC). Any Amateur Radio Operator, or groups of Amateur Radio Operators, can request an allocation of 44Net IP addresses.
44net.cloud - A prototype / proof of concept for access into 44net via a Virtual Private Network. This service was set up by a member of ARDC’s Technical Advisory Committee.
Amateur Radio Internet Exchange (ARIX) - “internet exchange point for licensed amateur radio operators for the use of networking research, development, and education.“
APRS-IS - Network of Internet servers that enables APRS iGate for APRS nodes to send local information to the Internet and make APRS data viewable on a web browser.
axmail - Amateur Radio to SMTP email gateway.
SMSGTE - A gateway between Amateur Radio APRS messages and Short Message Service (SMS) messages.
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Networking - LoRa
New0090 Austin Mesh - City-wide text messaging system based on LoRa technology.
New0090 Project OWL / ClusterDuck Protocol - Open source mesh network - from IBM (really).
TCP/IP over LoRa Radios - LoRa radios are a "fertile area for future development".
TinyGS Network - Network of receivers for experimental satellites that downlink data using LoRa.
TinyGS - Inexpensive Ground Station - ~$40 satellite data receiver for experimental satellites that downlink data using LoRa.
Unsigned.io RNode LoRa Radio - LoRa Amateur Radio for experimentation with LoRa technology.
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Networking - VHF / UHF - Hardware - Modems and Terminal Node Controllers (TNCs)
Decentralized Amateur Paging Network (DAPNET) - Interesting project in Europe of using paging technology in Amateur Radio for message distribution.
Digirig - Compact audio interface, optimized for use with portable radios.
DRAWS - The Northwest Digital Radio DRAWS is a capable built-for-purpose sound card modem for Amateur Radio for Raspberry Pi. I was particularly impressed that it was engineered with higher speed modes in mind such as 9600 bps (and faster) FSK and has no bandwidth-damaging transformers. Has been out of production, but reportedly will resume in late 2022. It's well-supported with various data communications software.
DRA Series Audio Adapters - Best performance for using high speed “audio interface modes” such as VARA FM. The DRA-SR units are replacement boards for Tigertronics SignaLink units.
Kantronics KA-Node and K-Net (link is KPC-3+ manual - see KA-Node beginning page 104) - The Kantronics KPC-3+ (below) is typically used as a digipeater or a mobile APRS modem. For years, or decades, Kantronics has incorporated the functionality of Net/ROM / TheNET Amateur Radio Packet Radio networking into its units, and that capability is under-appreciated and underused. Kantronics has even incorporated the ability to "stack" multiple units and network them via their serial ports.
KPC-3+ - If there's a Terminal Node Controller that deserves to be called "venerable", that's this unit. It's been in production for decades now, and is considered very stable and is probably used at more APRS digipeaters than any other unit.
KPC-9612XE - Kantronics' most advanced Terminal Node controller, including two radio ports and support for 4800, 9600, 19200, 38400 bps with GMSK / DFSK modulation.
MFJ-1270PI - TNC add-on board for a Raspberry Pi.
New0090 - Mobilinkd TNC4 - Successor to TNC3 - Bluetooth APRS TNC with battery power and 1200 / 9600 bps KISS TNC for use with portable radios. Also supports M17 protocol.
MUX-25 - Allows an analog repeater to also handle digital voice and data modes.
Nexus DR-X - A kit that uses a Raspberry Pi 3 or 4 for multiple Amateur Radio modes. Tightly coupled, well-maintained software makes this system easy to use.
NinoTNC - A “from scratch” KISS TNC designed specifically to support Terrestrial Amateur Packet Radio Networks (TARPN). The NinoTNC supports AX.25 packet radio at 1200 / 2400 / 4800 / 9600 bps and various modulation methods. The Nino TNC also supports Improved Layer 2 Protocol (IL2P) Forward Error Correction (FEC).
OpenModem - Open source packet radio modem.
Tigertronics SignaLink USB is the easiest and best-supported audio adapter to use for data communications in Amateur Radio, but it doesn’t support the highest speeds of data communications such as VARA FM.
Unsigned.io OpenModem TNC - What can I say... I'm a fan of TNCs, especially ones designed and produced in the 21st century. OpenModem has a unique capability of logging AX.25 packets to an SD card for later analysis.
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Networking - VHF / UHF - Hardware - Radios
6-pin Mini-DIN Adapters and cables for radios that have flat audio outputs with "non-standard" (in Amateur Radio) connectors
Most Amateur Radio transceivers that provide "flat audio" (bypasses pre-emphasis and de-emphasis voice stages for "full range" audio) use a 6-pin MiniDIN connector with standardized connections. Some do not, but there are adapters available that provide the 6-pin MiniDIN connection:
- Alinco 6 Adapter for DR-06T, DR-135, DR-235, and DR-435 (all vintages), and Yaesu FT-2600; Masters Communications.
- Bridgecom BCM Radio's HD-15 Accessory Port to NW Digital DRAWS HAT 6 Pin Mini Din Packet Port Plug for Bridgecom BCM-144, BCM-220, and BCM-440; Ham Made Parts.
- Motorola 16 Adapter for many Motorola radios that utilize a 16/20 dual row option connector; Masters Communications.
- Motorola 16 Pin Mini Din Packet Adapter for Motorola radios with the standard 16 pin accessory port for packet/APRS; RPC Electronics.
- AC-25 Adapter for Alinco DR-X38 and TYT TH-9000 from Masters Communications; use with Alinco 6 (above) for 6-pin MiniDIN; Masters Communications.
- TYT TH-9000D Mini Din Packet Adapter for TYT-TH-9000D; RPC Electronics.
902 - 928 MHz Radios
Both of the above are small, lightweight data radios for drones, "up to" 40 km and 250 kbps. There are lots of links on these two pages.
Arrow TNC - A full fledged TNC with built-in Bluetooth Low Energy (BLE) connectivity and incorporating a 144 MHz (2 meter) radio.
BridgeCom Systems Systems BCM-220 - 222 MHz radio with a connection for flat audio (non-standard connector), suitable for higher speed data communications such as VARA. The manufacturer claims that production of this radio will resume in late 2022. See 6-pin Mini-DIN Adapters above for making this radio easier to use for data.
CSI CS800D Plus Dual Band DMR and Analog Mobile Radio - A really interesting concept - bring out the internal data flows of a modern DMR radio to an external processor for expanding the capabilities of the radio beyond the manufacturer's original design. This is very much a work in progress, thus I suggest basing your purchase decision on what this radio can do now. There is no detailed plan (that I've seen) for "capability expansion". See this recent ZR article.
DRA-MIX-MUX - "The DRA-MIX-MUX is used in instances where you want to connect different applications simultaneously to one radio using separate radio interfaces."
FreeWave Technologies FGR-2 Series of 902-928 MHz Radios - FreeWave Technologies makes the most impressive data radios that I've seen for 902-928 MHz operating under Part 15.247 (license exempt in Industrial, Scientific, and Medical - ISM bands). The primary reason FreeWave radios are so robust is that they use Frequency Hopping Spread Spectrum (FHSS), thus they can "punch through" in the crowded 902-928 MHz band when "static channel" radios cannot.
Halo TD-XPAH - Radio for 902-928 MHz based on 802.11ah and 802.11s.
Ham Radio Projects SHARI PiHat - Kit (or optionally, assembled) that integrates a ~0.5 watt (144-148 or 440-450 MHz) radio, modem, and a Raspberry Pi 4.
HobbyPCB Radio Shield RS-UV3A - 200 mW radio for 144-148 / 222-225 / 440-450 MHz that can be controlled via serial port and ATDT commands.
HYS TC-8900R - 29 MHz, 50 MHz, 144 MHz, and 440 MHz “Data” Radio - Best explained in the Zero Retries 0018 article.
Icom DV Fast Data Mode - A feature of newer Icom D-Star radios which inserts data into the voice portions of a 4800 bps D-Star transmission. DV Fast Data Mode achieves 3480 bps instead of the usual ~900 bps data rate of D-Star. DV Fast Data Mode is supported by all (?) D-Star DV repeaters. Although the primary software for D-Star data is D-RATS, a quick look at the D-RATS website doesn’t show any mention of DV Fast Data Mode.
Icom IC-9700 - The only radio in production (that I'm aware of) that covers 144-148 MHz, 430-450 MHz, and 1.24 - 1.3 GHz.
Icom ID-RP1200VD - 3rd generation D-Star repeater for 1200 MHz offers data speeds of “128 kbps”. The compatible user radio is the Icom IC-9700.
Kenwood TM-V71A - This is my current personal favorite radio for VHF / UHF networking. Despite reports of it being out of production, it’s the Dracula of Amateur Radios - it keeps rising from the dead, with new units continuing to be available.
New Packet Radio (NPR) - Despite the name, has no commonality with “traditional” Amateur Packet Radio. It achieves 500 kbps in a 100 kHz channel on the Amateur Radio 420-450 MHz band, and is based on TCP/IP (and connects via Ethernet). NPR was featured in an IEEE article.
New0090 NPR units assembled:
- Elekitsorparts (labeled FUNtronics) - NPR-70 v05 Modem by F4HDK.
- Localino - New Packet Radio Modem Version 2, NPR-H 2.0; includes an integral 7 watt transmitter.
PicoAPRS Transceiver V4 - Integrated APRS Radio tracker, but can operate as a TNC via Bluetooth or Wi-Fi.
TYT TH 9000D - Radios available on Amazon for 144-148 MHz, 222-225 MHz, and 440-450 MHz that don't have flat audio interface, but "easily modified. Best explained in the Zero Retries 0018 article.
Yaesu FTM-6000R - Introduced in 2022; it includes a “flat audio” interface for data communications that is the primary feature of the TM-V71A.
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New0090 Networking - VHF / UHF - Software - Mobile Phone Apps
aprs.fi - APRS
RadioMail - Winlink email
Ribbit - Data communications via any two-way radio; modem is a smart phone app, which transmits and receives data to / from the radio acoustically.
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Networking - VHF / UHF - Software
Chattervox - An AX.25 packet radio chat protocol with support for digital signatures and binary compression. Like IRC over radio.
Dire Wolf (Decoded Information from Radio Emissions for Windows Or Linux Fans) is a software Terminal Node Controller (TNC) that implements all of the elements of a hardware TNC, only requiring an audio interface and a host computer such as a Raspberry Pi. Using the compute capability of the host computer, Dire Wolf provides far more accurate decoding of packet signals, and also provides APRS digipeater and Igate functions. Unlike a hardware TNC, Dire Wolf can be accessed via a TCP/IP network (via sockets) and can also be accessed via “KISS” interface.
F6FBB FBB - Very capable Packet Radio Bulletin Board System (BBS). Yes, BBS' are still useful.
FLAMP - One of the modes from the fldigi suite that streams files - one transmitter, many receivers. Receivers can be entirely passive - no acknoledgements required; if there's an error in one block, the receiver waits for a "fill" from a future transmission cycle. See also RadioMirror.
Flexnet - Advanced packet radio networking, that fixed many of the issues of digipeating, mesh networking (Net/ROM). It is reportedly still in use in places, and deserves more research. This discussion and this discussion is helpful. Another technology that should be trivial to reproduce and advance using current technologies.
Forward Error Correction - As an example of the ongoing technological innovation in Packet Radio networking, Dire Wolf and the NinoTNC have implemented 9600 bps (and faster?) data rates and Forward Error Correction (FEC).
- FX.25 - FEC that is interoperable with AX.25, implemented in Dire Wolf.
- Improved Layer 2 Protocol (IL2P) - Integrated (not added-on like FX.25) FEC method developed for the NinoTNC (also implemented in Dire Wolf).
Both IL2P and FX.25 make 9600 bps communications much more usable as they can correct single bit errors without retries, unlike AX.25.
HAMNET Access Protocol (HNAP) - Software image for data communications on 420-450 MHz using ADALM Pluto Software Defined Transceivers. We need a lot more of these practical examples of Software Defined Radio technology.
KL4YFD Sound Card Modes - Not only is he developing new modes, but he's sharing his source code. Of particular node are his OFDM modes that take advantage of "flat audio" input / output on data radios.
Linpac - Amateur Radio AX.25 chat and PBBS program using Linux's AX.25 stack.
multimon-ng - Decodes various obscure data modes, including POCSAG (paging). Imagine the robustness of paging used in Amateur Radio now that we all have access to high resolution timebases and flexible data transmission modes.
MultiPSK - Like multimon-ng, integrates a number of data modes.
(USA) Nationwide Amateur Radio Packet Directory by WW2BSA
OscarDelta IP Over AX.25 - OscarDelta IP Over AX.25 is a packet radio software developed for amateur radio operators to provide TCP/IP communications.
Packet Radio Map - No info available - opens to a map of various Packet Radio nodes.
Packet Radio Routers - Packet Radio networking on Amateur Radio VHF / UHF is now multiple decades old. Despite this maturity, new packet radio networking techniques are continually being developed.
- BPQ32 by John Wiseman G8BPQ has been refined over decades and is an omnibus software suite that provides network node, bulletin board system (BBS), chat server, email, and TCP/IP interoperability.
- JNOS - Sometimes called the “Swiss Army Knife” of Packet Radio, JNOS includes a packet node, BBS, email mailbox system, chat server (chatroom), and especially a Packet Radio to TCP/IP gateway. An interface to VARA FM was recently added.
- XRPi (previously, Xrouter) - Very capable Amateur Packet Radio router.
- URONode - Similar capabilities to BPQ32, including TCP/IP interoperability, network node, BBS, email handling, and APRS iGate integration.
QT Soundmodem (QtSM) - Audio interface modes; multi-platform port of UZ7HO's SoundModem packet radio “engine”.
RadioMirror - Basically, streaming blocks of files, with a checksum. I wrote a blog post on RadioMirror that explains my vision.
SV2AGW Packet Engine is a software TNC with some applications for APRS.
Terrestrial Amateur Packet Radio Network (TARPN) is a networking philosophy that packet radio networks should consist of nodes of multiple simplex links on unique frequencies. TARPN provides a software image for a Raspberry Pi and copious documentation for creating TAPRN networks.
VARA FM - Audio interface mode; remarkable achievement that when used with a VHF / UHF radio that has a flat audio input / output and a high performance audio interface (such as the Masters Communications DRA series) achieves robust connections of up to 25 kbps on a standard 20 kHz VHF / UHF channel.
Xastir - Open source APRS client, ported to Windows, Mac, and Linux; actively maintained.
Worldwide Amateur Radio XROUTER Packet Directory
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Networking - 1240 MHz and Above
Amateur Radio Emergency Data Network (AREDN) - Replacement firmware (based on OpenWRT) for Wi-Fi and Wireless Internet Service Provider (WISP) radio units that reconfigure the hardware for the Amateur Radio portions of spectrum in the 2.3 GHz and 5.8 GHz bands. Adds features and capabilities such as automatic handling of IP address selection, DHCP, and DNS that make it relatively easy to build meshed Amateur Radio microwave IP networks. Implements Amateur Radio specific requirements such as no encryption. AREDN networks are rapidly growing within Amateur Radio.
New0090 Amateur Radio 2.4 GHz amplifiers (for AREDN 2.3 - 2.4 GHz or QO-100 uplink):
The Es’hail 2 / QO-100 geostationary satellite uses 2.4 GHz as uplink, thus a bit more than a few milliwatts of power is required to access QO-100 in Geosynchronous Earth Orbit (GEO), even using highly directional antennas.
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E-REON 2.4 GHz 2W amplifier for QO-100 (2 watts)
- E-REON 2.4 GHz 30W PowerBlast amplifier (30 watts)
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SG Lab 20 Watt 2.4 GHz Amplifier (low power input) - See above; this version is designed for the very low power output of Software Defined Transmitters.
GL-iNet AR-300M16 (Shadow) - Small, inexpensive Wi-Fi router that is in production and supported by AREDN firmware (AREDN Stable) and available on Amazon. Ideal for experimenting with AREDN (buy three for personal experimentation with AREDN mesh networking). This unit is a good replacement for the GL-iNet AR-150 / AR-150ext.
HamWAN - Microwave IP network system developed in the Seattle, Washington area; uses 5.9 GHz and 44Net IP addresses.
HAMNET (Highspeed Amateur radio Multimedia NETwork) - Network in Europe consisting mostly of microwave links.
New0090 Icom IC-905 - Not yet released radio Icom claims that the IC-905 will be available in 2023; includes 144 MHz, 430 MHz, 1.2 GHz, 2.3 GHz, 5.6 GHz, and optionally 10 GHz. Formerly known as the SHF-P1.
Icom Digital Data (DD) Mode Repeaters (Networks) - DD Mode is 128 kbps on 1240 - 1300 MHz implemented in the Icom ID-1 and Icom IC-9700 radios, and two repeaters. Each DD repeater is a defacto network. This info is from Zero Retries 0009:
The D-Star DD mode - ID-1 user radios and ID-1 repeaters on 1240 - 1300 MHz, are still in use in a number of areas. I put out a query to the Groups.io D-STAR23cm mailing list and feedback was that there are active D-Star DD 1240-1300 MHz “repeaters” in these areas:
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Atlanta, GA
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Dallas, TX
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Detroit, MI
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Huntsville, AL
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Las Vegas, NV
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Minneapolis / St. Paul, MN
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New Mexico (cities unstated)
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Orlando, FL
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Vancouver, BC
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Walburg (Georgetown / Austin), TX
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Washington, DC
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Wausau, WI
Mid-Atlantic IP Network (MAIPN) - Microwave network in Maryland and Northern Virginia, USA.
Mimosa Networks - Some Mimosa Networks units are compatible with the Amateur Radio 10.0 - 10.5 GHz band. For sales of their 10 GHz units in the US, Mimosa Networks requires proof of Amateur Radio license.
OpenWRT - Open source firmware for routers and Wi-Fi access points. It's the basis for AREDN and many other interesting projects.
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Part 15 Microwave - Point to Point (P-P) and Point to Multipoint (PMP) operating in license-exempt portions of spectrum (Part 15 rules) such as 5.8 GHz, such as the MikroTik LHG HP5, are not incompatible with Amateur Radio. One advantage of such usage of Part 15 devices and spectrum is that encryption is allowed.
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Networking Organizations - Local
Delaware Packet Network - Delaware, USA.
EastNet Packet Radio Group - Florida, Connecticut, New Jersey, New York, Pennsylvania, USA. They also have a mailing list.
Hudson Valley Digital Network - Upstate New York (I think), USA.
Kentuckiana Digital Experimenters Group, The - Northern Kentucky, USA.
Mount Baker Amateur Radio Club Digital Group - Bellingham, Washington, USA.
North Carolina Packet - North Carolina, USA.
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Organizations - National / International
Amateur Radio Digital Communications (ARDC) - Provides substantial grants to Amateur Radio, research, and education. Also administers 44Net, the IPv4 address block (44.0.0.0/9, 44.128.0.0/10) allocated for Amateur Radio worldwide.
APRS Foundation - In formation in 2022, this organization was formed in the wake of the death of Bob Bruninga WB4APR, the creator of Automatic Packet Reporting System (APRS) to potential coordinate the further development of APRS.
Information Technology Disaster Resource Center (ITDRC) - Volunteers providing Emergency Communications (mostly, sans Amateur Radio involvement). In my opinion, this will soon become the model of volunteer-based emergency communications response - providing emergency broadband communications to the public using Information Technology - Part 15 microwave networks, Wi-Fi, satellite, Ethernet, etc.
HamOpen is a new organization. From their web page:
Our purpose is to act as an [umbrella] 501(c)3 for funding of Open Source projects for Amateur Radio. We are a registered Public Benefit Non-Profit Corporation in the state of California.
We are filing our 1023 application to be a 501(c)3 with the IRS. We had that professionally prepared. But the IRS will probably take months to approve it. There will be more information as there is time to develop the web site.
Ham Radio Science Citizen Investigation (HamSCI) - Sponsors scientific investigations involving Amateur Radio operators and Amateur Radio spectrum.
Packet Radio User's Group - Japan
QRP International - I'm much more of a fan of QRP (weak signal) radios now that WSJT exists.
TAPR is a unique organization within Amateur Radio. From their About page:
TAPR is a non-profit 501(c)(3) organization of amateur radio (“ham”) operators who are interested in advancing the state of the radio art. The initials stand for “Tucson Amateur Packet Radio” but today the organization is much broader than that: we long ago became an international organization, and while we still support packet radio our areas of interest have expanded to include software defined radio, advanced digital modulation methods, and precise time and frequency measurement.
TAPR’s main activities are education and knowledge sharing through conferences, publications, and Internet resources; and research, development, and sales of unique products that assist amateurs and other experimenters. TAPR strongly endorses technology sharing, and in 2007 released one of the first licenses designed for open hardware projects, the TAPR Open Hardware License. With rare exceptions, all hardware and software developed with TAPR support is licensed under open source or open hardware terms.
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Software Defined Receiver / Transmitter / Transceiver (VHF / UHF / Microwave)
ADALM-PLUTO - This is the easiest and most accessible Software Defined Transceiver I’m aware of. It’s fully compatible with GNU Radio and thus is a fantastic learning tool… which is its primary audience, though it’s used a lot in Amateur Radio.
Airspy (US) - SD Receivers, optimized for HF; US distributor has a wider selection of accessories than parent (UK).
aprs-sdr - An APRS Tracker with HackRF, WebUSB, and WASM.
New0090 CaribouLite RPi HAT - An unusual Software Defined Transceiver that will work up to 6 GHz that’s optimized in both form factor and function to work with the small, but capable Raspberry Pi Zero 2 W. This was previously in the "Interesting Projects" category, and as of 2023-03 is shipping / generally available.
Dragon OS - (Amateur Radio adjacent) “Out-of-the-box Lubuntu 20.04 based x86_64 operating system for anyone interested in software defined radios.”
GNU Radio - If you can’t do it with a Software Defined Receiver or Transceiver and GNU Radio (software), it may not be possible.
HackRF One - Software defined transceiver covering any contiguous 20 MHz 1 MHz - 6 GHz.
Lime SDR - SD Transceiver - “Big Sister” (more capable than) the Lime SDR Mini (see below).
Lime SDR Mini 2.0 - This is one of the more capable, entry level SD Transceivers and was popular enough to redesign when critical parts became unavailable. Successor to LimeSDR Mini which is now discontinued.
LimeRFE - Companion unit for Lime SDR / Lime SDR Mini - driver amplifier / filter for Amateur Radio HF / VHF / UHF / Microwave bands.
KiwiSDR - A software defined receiver designed specifically for the Beaglebone series of single board computers. The combination is specifically designed to be used as a web-based receiver, accessible locally or (preferred) accessible from the Internet.
KrakenSDR - Basically 5x Software Defined Receivers integrated into a single board and operated on the same USB chain and fed by a single timebase, making it possible to discern signals arriving at different times into the various receivers. Think passive direction finding - no switching between units, no moving antennas. It’s my guess that this could probably be made into a very capable multi-band Software Defined Receiver, such as simultaneously monitoring the Amateur Radio 50, 144, 222 bands, and two of the three 10 MHz segments of the 420 - 450 MHz band.
Nuand Blade RF - A very knowledgeable source stated that the next step up in performance per dollar for a software defined transceiver (from an ADALM-PLUTO) is the Blade RF series.
Open IP over VHF / UHF - A project by David Rowe VK5DGR to create a system that will do native TCP/IP over VHF / UHF frequencies, at a data rate of up to 100 kbs, at a range up to 15 km (urban). The transmitter is a Raspberry Pi. The receiver is an RTL-SDR dongle. This system is mostly software. It sounds… speculative… but I’m not betting against VK5DGR. Parts 1, 2, 3, 4, 5.
PACKRAT - Tutorial of data communications via Software Defined Radio - the entire stack written from scratch.
PiSDR - "Modified Raspbian image with the latest SDR software pre-installed and ready to go. Compatible with every Pi".
New0090 Pluto+ - Software Defined Transceiver with two transmitters and two receivers, 70 MHz through ~ 6GHz.
Red Pitaya - This is the most capable software defined transceiver that I know of. It's so sophisticated and capable that it wasn't originally a platform for radio experimetation. As I understand the story it was created as a multifunction radio test set. As it evolved, it seems to be the favorite Amateur Radio software defined transceiver of those who can write digital signal processing software.
New0090 RFzero - Arduino-based Software Defined Transmitter.
rpitx - “General radio frequency transmitter for Raspberry Pi which doesn't require any other hardware…“
RTL-SDR.com Dongles - This is the company that popularized “SD receiver dongle”; impressive performance for the price. Their products are widely (and poorly) cloned, so pay careful attention to their authorized sales channel. For a very small premium over the cheap-cheap versions, these Software Defined Receiver dongles are the best ones if you want to experiment inexpensively with Software Defined Radio (receive-only).
New0090 SDRPlay SDRConnect - (In development) New generation, more capable, cross-platform software for SDRPlay's Software Defined Receivers.
SDRPlay RSP-1A - My favorite “better than RTL-SDR” Software Defined Receiver. From memory, these can do up to 7 virtual receivers in any contiguous 10 MHz from 1 kHz through 2 GHz. Radio adjacent) SD Transceiver for Raspberry Pi Zero / Zero W / Zero 2 W.
SDRServer - Streaming data to multiple users from a software defined receiver device.
Softrock Software Defined Radios - When they debuted in 2005, these neat little kits answered my longstanding question about how simple a radio you could make with modern computer hardware doing the "heavy lifting".
New0090 Smart Radio Concepts Charly 25 - Software defined transceivers based on Red Pitaya Software Defined Transceiver.
Universal Radio Hacker - A complete suite for wireless protocol investigation with native support for many software defined radios.
YARD Stick One - (Amateur Radio adjacent) Hard to get a simpler SD transceiver than this one.
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Satellite / Space (one of the "big three" raison d'êtres of Zero Retries)
AmbaSat-1 Satellite Kit - Build up a board for inclusion in a future satellite.
AMSAT-DL - AMSAT Germany is one of the most active “chapters” of AMSAT; one reason might be a strong relationship with the European Space Agency (ESA).
AMSAT-NA - AMSAT North America (and owner of the amsat.org domain).
AMSAT-UK - AMSAT for United Kingdom.
(There are many other AMSAT organizations in other countries.)
AMSAT-NA Strategic Plan 2021 - 2035
ARISS / ARISS-USA - One of my proudest boasts as an Amateur Radio Operator is that there are two Amateur Radio stations on the International Space Stations, and when not being used for voice contacts with schools, they are often switched into APRS / packet radio digipeater mode, which can be a lot of fun for us data folks. Last year, ARISS-USA was established as an independent entity in the US, and it received a significant grant from ARDC to further their development efforts. One thing I didn’t know until recently that ARISS is actively planning for a future for Amateur Radio on space missions / systems beyond the International Space Station including private space stations and missions to Luna… and beyond.
CubeSat Simulator is a project by Alan Johnston KU2Y to make it possible to build a demonstration unit of a CubeSat, using 3D printed structural elements, populating a circuit board, and other common electronic components. The idea is to create a unit that can be held in one’s hand that illustrates the essential elements of a picosatellite, complete with batteries, solar panel, sensors, and a telemetry transmitter.
Earth-Moon-Earth (EME) aka Moonbounce - One of the ultimate fantasies of Amateur Radio… at least for me… is a bucolic summer night when Luna is full in the sky and having an antenna array pointed at Luna, and a radio system tuned to the most popular EME frequencies such as 144-148 MHz or 420-450 MHz and listening to the conversations from all over the world bouncing off Luna. Better antenna systems (which are more expensive) and power amplifiers make for more EME fun.
FLTSATCOM System - Fleet Satellite Communications (FltSatCom) System is a US Navy geosynchronous "bent pipe" wide bandwidth transponder pair of satellites. I wrote an article discussing FLTSATCOM.
New0090 NPR-VSAT - Adaptation of New Packet Radio to provide TCP/IP services for QO-100.
Othernet - Very cool project to do "datacasting" from satellite. Not entirely a new idea, but a new approach.
Phase 4B Payload for North America GEO Satellite - (Thank goodness for the Internet Archive's Wayback Machine!) This was a well-conceived, well-scoped realistic project that seemed realistic. Apparently the host satellite was canceled. It would have been great for data communications.
QO-100 is an Amateur Radio payload (transponder) on the Es’hail 2 geostationary satellite above the Eastern hemisphere. Uplink to QO-100 is on 2.4 GHz and downlink is on 10 GHz. There are many Amateur Radio experiments being conducted on QO-100, and it sure seems like a lot of fun.
SatNOGS is a network of [receive-only] satellite ground stations focused on tracking and receiving low earth orbit (LEO) cubesats, especially those involved in student research. An Amateur Radio license isn’t required to participate in SatNOGS as each ground station only receives. SatNOGS publishes how to build a compatible ground station, and some parts can be 3D printed, so a SatNOGS station is an excellent “Maker” project combining electronics, radio technology, and physical construction. There’s a very good Frequently Asked Questions page that gets you up to speed fast on SatNOGS.
UHF-Satcom.com - Good reference site for satellite information.
WSJT-X JT4 / JT65 / Q65 modes - These are just three of the many amazing “Weak Signal Joe Taylor” modes; specifically designed to make it possible for modest Amateur Radio stations to work Earth-Moon-Earth (Moonbounce). Bouncing one’s signals off Luna… is just cool.
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Special Categories
Apartment / Condo stealth VHF antenna - modify a satellite receive dish into a stealth 144-148 MHz antenna.
New0090 Custom Crystal Manufacturers (for crystal-controlled radios)
- Andy Fleischer (Germany)
- Klove Electronics (Belgium)
- KRYSTALY, Hradec Králové (Czech Republic)
Digital Amateur [Radio] Television - DATV - Amateur Radio has been able to use “fast scan” television since shortly after television became commercially practical. A new generation of Amateur Radio Television based on digital technology is emerging, and those folks seem to be having a lot of fun!
Build-A-Pi - Utility to install a user-selectable suite of many different Amateur Radio applications onto a Raspberry Pi.
Creating a 2m Fm Repeater with a Raspberry Pi (B) and a RTL dongle - About as bare-bones a repeater as it gets; the transmitter is almost entirely software.
New0090 Digital Amateur Television (DATV) - Digital Amateur Television is very active in certain areas.
EZNEC Antenna Modeling Software (now free for use).
FCC Experimental License (Part 5) - Experimental licenses have been granted for Amateur Radio experimentation to prove out new techniques and technologies that aren't compatible with existing FCC rules.
FCC Special Temporary Authority (STA) - STAs have been used for Amateur Radio experimentation to prove out new techniques and technologies that aren't compatible with existing FCC rules.
HamIQ (Inovato Quadra) / HamPC (PC running Linux) / HamPi (Raspberry Pi) are bundles of 100+ Amateur Radio applications for use on inexpensive computers running Linux. Controversial because it stealthily installs BOINC - a distributed computing application uses Internet bandwidth and compute power; only mentioned in the license information which claims you are allowed to disable BOINC, but not uninstall it.
Ham Made Parts - Custom data cables for various Amateur Radios and modems.
Laurel Volunteer Examination Coordinator (VEC) - Low overhead, no cost Amateur Radio license exams; the 21st century method of doing Amateur Radio testing.
multimon-ng - Audio interface modes that decode various obscure data modes, including POCSAG (paging).
MultiPSK - Many audio interface modes (some I’ve never heard of).
"NanoVNA" - This came out of nowhere a few years ago - an inexpensive, handheld, open source Vector Network Analyzer. These are just amazing. It's a bit of a learning curve to understand how to use them, but they're very powerful. Update 2022-06-16 - I was contacted by a person who claimed to be a developer involved with "the real NanoVNA", claiming that the link I originally provided is to an unlicensed (? Open Source?) clone rather than to the "real NanoVNA". I'm not equipped to sort out which of the "NanoVNA" is more "real" than another, thus I removed the embedded link. If you're interested, do your own research and form your own conclusions.
New0090 Phase Dock Universal Workbench System - Easy to use "project enclosure system, makes it easy to put together multiple modules, cables, etc. into a single unit.
PiMod Zero - Pico television transmitter that works with a Raspberry Pi Zero. It’s intended to drive legacy analog televisions, but being mostly software, it seems like it could be adapted to (very low power) Amateur Television transmission.
Project Boondock Echo - Single frequency "repeater"; voice equivalent of a digipeater - receive and store then retransmit.
Raspberry Pi Computers - Although they're mostly unobtainium at the moment, they are the least expensive, most flexible, best supported, most power efficient microcomputers available at the moment, and in my opinion, the first choice for powering Amateur Radio projects.
Remote Rig Controller - $14 dongle can do remote control of a radio.
Reticulum Network Stack - An amazing amount of work has gone into this project to (as I understand it) use any radio technology to form independent, secure mesh networks. Not quite applicable to Amateur Radio because of the strong encryption.
New0090 - RNode - Open, free and unrestricted digital radio transceiver. It enables anyone to send and receive any kind of data over both short and very long distances. RNodes can be used with many different kinds of programs and systems, but they are especially well suited for use with the cryptographic networking stack Reticulum.
RS232 Serial Wi-Fi Modem for Vintage Computers V3 - My interest in this device was instead of trying to cable up a bunch of TNCs via RS-232 to USB adapters, just use this dongle to do all the networking via Wi-Fi. With this, every RS-232 device, essentially, has its own TCP/IP router.
Starlink - In my opinion, Starlink is the most stable Internet access for Amateur Radio use because it’s relatively immune to local Internet outages such as damage to fiber, power outages, etc. If you want to provide backup communications in your community / neighborhood via Winlink, APRS-IS, etc. , Starlink is ideal as it will work as long as it has power (and open sky). It’s even more useful now that Starlink has enabled nomadic use.
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Speculative Ideas
Includes legacy systems that might be instructive for future projects or potentially revived with current technology.
APRS as A Hailing Channel - This was an intriguing idea by Bryan Hoyer K7UDR. All Amateur Radio services in an area - Winlink, etc. should advertise on APRS.
Coastal Chipworks TNC-X - Now out of production and the company has closed. This was a great TNC - KISS so it was really stable.
DAMA - Another Network Solution - Describes a "Coordinator / Worker" network for Amateur Radio that would reduce collisions common in Collision Sense Multiple Access / Carrier Detect (CSMA / CD) networks.
Data over Digital Mobile Radio (DMR) - It occurred to me a few years ago that all the Amateur Radio DMR repeaters that are being built are, at their core, data repeaters. The DMR specification makes provisions for data, but no one seems to know much about how to do data over DMR. These Maxon DMR data radios deserve some experimentation.
Decentralized Channel Management in Scalable Multihop Spread-Spectrum Packet Radio Networks - Seminal 1995 MIT thesis of Timothy Shepard KD1KY. The thesis posits that radio data networks can scale considerably better on common channels than current practice if each radio broadcasts its proposed transmission schedule, and the other radios on the channel adjusted their transmission schedules accordingly. The network would not require a "master controller" and new radios will be accommodated dynamically. KD1KY's inspiration for this thesis paper was Amateur Radio Packet Radio. Such a system wasn't practical to implement with 1995 Amateur Radio technology... but it's now 27 years later.
Doodlelabs Radios - These were a brief experiment in combining a Wi-Fi chipset with a transverter to use Wi-Fi protocols in the Amateur Radio 420-450 MHz band. 802.11 uses a 22 MHz channel, and transverted to 420-450, it barely fits. Other not-quite-Wi-Fi variants can have a channel size as small as 5 MHz. I have some of these radios and need to find some supporting documentation. Yet again, it's an interesting idea for reimplementation with current technology.
DFQF2 T7F Data Radio - Like the Kantronics D4-10, this radio is now out of production and mentioned here as inspiration for a hoped-for new generation of data radios for Amateur Radio. The T7F was more advanced than the D4-10, including frequency agility. There were several excellent data radios for Amateur Radio made in Germany, but none remain in production (that I know of).
High speed Ax25 network in Slovenia - Archive that includes a 10 Mbps AX.25 TNC... in 2006.
FaradayRF - This was a noble effort to develop a new Amateur Radio data radio for the 902-928 MHz band, from 2016 - 2019. It faded out without much notice, but it lives on via the Internet Archive and their Github page.
New0090 - FidoNet - Peer to peer messaging / bulletin / file transfer system, perhaps applicable to Amateur Radio now that we have reasonable transfer speeds such as VARA FM - 25 kbps.
Inexpensive Multi-Megabaud Microwave Data Link (via Internet Archive) - In December 1989, Glenn Elmore N6GN and Kevin Rowett N6RCE published this article in Ham Radio Magazine about a microwave data communications link operating at 10 GHz and 2 Mbps. In 1989, the radio was comparatively easy, but the interface to the computer was relatively hard.
IPv6 over Amateur Radio - One of the valid criticisms of IPv4 over Amateur Radio is that the headers were very large, consuming considerable airtime just for the headers. While there were some implementations of header compression in the original TCP/IP over Amateur Radio packages, header compression wasn't standard. In IPv6, header compression is standard, so perhaps IPv6 over Amateur Radio is a "fertile area of research".
Kantronics D4-10 Data Radio - It's sad that in many ways the long-discontinued Kantronics D4-10 was a high point in packet radio radios. It featured a wide bandwidth that could do 19,200 bps (and faster), 10 watts transmit power, minimal design (no fancy faceplate), and best, was designed for data, not a radio designed for voice that kind-of does data. Because it uses crystals for frequency setting (which are near-unobtanium now) it's not that useful now, but it is a benchmark for what a data radio for Amateur Radio could and should be - minimalist, stable (with the mods mentioned in the link), and reasonable power output (though 25 watts would be better). I include it here as an inspiration for a new generation of data radios for Amateur Radio.
New0090 - Pacsat Broadcast Protocol Concept for transmit constrained email, bulletins, files, etc.
Puget Sound Amateur Radio TCP/IP Group - My paper for the 1995 Digital Communications Conference (DCC) on the 9600 bps bit regeration repeater network in the Puget Sound (greater Seattle), Washington area. I made this into an article on SuperPacket, with some updates.
UDRX-440 Software Defined Transceiver / Data Radio (PDF) - This was a project by Northwest Digital Radio that came agonizingly close to becoming a product. I profoundly wish it had, even with many rough edges. It was to be a 25 watt multimode data radio with all the features we wanted - flexible modems, full software control of transmit bandwidth, frequency, power, etc. There were good, valid reasons that it didn't quite make it. It's listed here as an example of what Amateur Radio needs as tools to make great leaps forward in becoming relevant again in the minds of most techies.
Wildernets - It's hard to grok Wildernets at first, but it's an amazing piece of software. It provides a web server, Voice over IP (VOIP), mesh networking, and more. It was ported to a now hard-to-find Wi-Fi router, and it's hoped that the developer will be able to find more time to work on it.
WA4DSY 56 kbps Modem - This was groundbreaking in its day and implemented in several areas, including repeaters in Vancouver BC and Atlanta, GA. It's still a fantastic achievement; it should be "easy" to implement this using current RF and DSP technology.
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History
I began this experiment to provide an Omnibus of Zero Retries Interesting information in Zero Retries 0039 and Zero Retries 0040. The idea was a quick (Ha!) "snapshot" of Zero Retries Interesting information in every decadal issue of Zero Retries. As new subscribers trickle in, I certainly don’t blame them for not exhaustively reading the 40 50 60 75+ previous issues (and counting) of Zero Retries to get up to speed.
I tried the Omnibus experiment again in Zero Retries 0050, Zero Retries 0051, and Zero Retries 0052. Yep, the Omnibus experiment "failed" even worse, requiring three issues. It was a good failure, simply because there were just more interesting things to report on then there was room in a two three newsletter(s) intended to be emailed. Prior to Zero Retries 0070, I decided to change the schedule of this Omnibus from every tenth issue to every fifteenth issue, thus the Zero Retries 0075 Omnibus is a light refresh of the Zero Retries 0070 Omnibus which had already been published because it was referenced in other publications.
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Depricated Entries
Eclectic Technology - A one page column by Steve Ford WB8IMY in every issue of QST Magazine; almost always Zero Retries Interesting. To read Eclectic Technology requires a $49 / year membership in ARRL ($25 / year for < 26 years old, but requires considerable effort to prove your age).
WB8IMY retired from writing Eclectic Technology (and the associated podcast).
FalconSAT-3 was a mostly retired United States Air Force research satellite which included a packet radio store-and-forward Bulletin Board System (BBS) on Amateur Radio frequencies. All official USAF activity has been concluded and now FalconSAT-3’s is only used for Amateur Radio.
FalconSAT-3 de-orbited in early 2023.
Southgate Amateur Radio News - Often surfaces Zero Retries Interesting topics.
The author of SARN became a Silent Keyboard in 2022.
TNC3 - Bluetooth APRS TNC with battery power and 1200 / 9600 bps KISS TNC for use with portable radios. Suceeded by the TNC4.
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End (of this installment) of Zero Retries Interesting Projects, Products, etc. for Zero Retries 0090. Look for the next installment concurrent with Zero Retries 0105 (approx. late June, 2023).
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Thanks for reading!
Steve Stroh N8GNJ
Bellingham, Washington, USA
Copyright © 2022, 2023 by Steven K. Stroh