Newsletter

Zero Retries 0233

2025-12-31 — 3400+ email Subscribers, UberSDR - New GUI for ka9q-radio, Pending ARRL Book - Digital Networking for Ham Radio, Let’s Encrypt Certificates Available for IP Addresses Without Domain Names

Steve Stroh N8GNJ

— 19 min read
Zero Retries 0233

Zero Retries is an independent newsletter promoting technological innovation in and adjacent to Amateur Radio, and Amateur Radio as (literally) a license to experiment with and learn about radio technology. Radios are computers - with antennas! Now in its fifth year of publication, with 3300+ 3400+ subscribers.

About Zero Retries

Steve Stroh N8GNJ, Editor

Email - editor@zeroretries.net

On the web: https://www.zeroretries.org/p/zero-retries-0233

Substack says “Too long for email”? YES

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In this issue:

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Footnotes for this Issue

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Commentary by Editor Steve Stroh N8GNJ

My thanks to Gerry Brown KK7GAB for renewing as an Annual Paid Subscriber (3rd year!) to Zero Retries in the past two weeks!

My thanks to My thanks to Prefers to Remain Anonymous 115 for upgrading from a free subscriber to Zero Retries to an Annual Paid Subscriber in the past two weeks!

My thanks to Bill Kreutinger KM6SLF for two years of being a Paid Subscriber to Zero Retries in the past two weeks!

Financial support from Zero Retries readers is a significant vote of support for the continued publication of Zero Retries.

3400 Email Subscribers!

Snipped from the Substack Dashboard today. Image by Steve Stroh N8GNJ

Just days before the end of 2025, the email subscriber count for Zero Retries has ticked up to 3400. The total readership of Zero Retries, via RSS, social media, pass-alongs, etc. is anecdotally much more than that number. I am grateful to all of you for “voting with your attention” that Zero Retries is contributing to Amateur Radio, and thus worth the work that I put into it. As I explain in every issue of Zero Retries in the section above, I’m am very grateful to the paid subscribers to Zero Retries that help to support Zero Retries financially.

Apologies For Publication Confusion

Thanks to those of you who reached out to check in on me if I was doing OK. It was appreciated! No health or other issues - the issue with Zero Retries not being published on schedule on Friday 2025-12-19 and 2025-12-26 was mostly poor planning on my part combined with busyness.

I had intended to take my “annual” holiday break and not publish Zero Retries in the last two weeks or so of the year in order to spend time with family over the Christmas / New Year holidays… but didn’t say anything about that in Zero Retries 0232.

There was also some last minute, barely scheduled travel just before Christmas by Tina and I to help out a friend. That kept us busy to the point where I didn’t get any laptop time to work on this issue of Zero Retries, until today.

I had wanted to implement the transition of Zero Retries to a new platform and migrate off Substack in December 2025, but as I’ve said previously, that’s a complicated process.

zeroretries.radio

That transition - Zero Retries being published on a platform other than Substack, is my highest priority for Zero Retries now. I’m determined that the transition will be implemented in January, 2026. At this point, I can reveal that Zero Retries on the new platform will be published using a new domain name:

zeroretries.radio

Currently that domain redirects right back here to Zero Retries on Substack, but soon enough it will point to Zero Retries on another platform.

While I hope to migrate the content of Zero Retries onto the new platform, that may not be possible (at least cleanly). We’ll see.

The Zero Retries Email List

… is going great! One of the nicest things about the Zero Retries email list is that there is a lot of community support and peer to peer information exchange happening on via the list. My thanks to all the participants. It’s also gratifying to see Zero Retries Interesting information posted on the list that I wasn’t aware of.

The Zero Retries YouTube Channel

https://www.youtube.com/@ZeroRetries is similarly going well (68 subscribers! Yoo Hoo!)

There’s a lot of Zero Retries Interesting content on YouTube, and while I’ve kind of been throwing a lot of stuff into the playlists on ZRYC, in the future I’m going to curate more selectively, such as creating specific playlists for topics such as Packet Radio (videos that I consider credible).

Synergy of Video Presentations, Zero Retries Guides, and the Zero Retries Book

I’ve been getting a lot of positive feedback and suggestions about the new Zero Retries Guide to HF Data Communications and my stated intention that it is the first of many Zero Retries Guides. I’m glad that I seem to have identified another “gap” in Amateur Radio that’s useful to furthering the mission of promoting Amateur Radio of the 21st century.

I intend that each Zero Retries Guide is going to be the basis of a three-way synergy - ZR Guides feed ZR video presentations feed chapters in the upcoming book.

Each Zero Retries Guide will be expanded into a brief video presentation (my goal is 10 minutes max) that will get posted on YouTube. These will be wholly original content, explaining a subject such as HF Data Communications, from the unique Zero Retries perspective. The idea is to “cross support” the (text) Zero Retries Guide with the (video) Zero Retries presentation. This addresses one of my primary plaints about video presentations (lack of deeper context), while addressing the near universal shift of information presentation in this era from text to video.

And then, between the Zero Retries Guide, and developing the presentation, and the feedback I receive from both, I can then “port” that information over to the equivalent chapter in the still in progress book - Zero Retries Guide to Amateur Radio in the 21st Century. After moving Zero Retries to a new publishing platform, this book is the next primary project of Zero Retries in early 2026.

Coming Attractions in 2026

My wife Tina KD7WSF, Zero Retries’ Business Manager often cautions me not to overpromise and underdeliver, and that’s a point well taken. With that in mind, I have reasonable confidence that I’ll be able to deliver on these near future projects.

Two big, important projects for Zero Retries in 2026 (besides the book) will be:

  • Porting Zero Retries content into Google’s NotebookLM and then sharing that out. There are limits on NotebookLM sharing, so this feature will be initially be offered to Zero Retries paid subscribers. That’s not a “shill” for additional Zero Retries paid subscribers, just a long overdue “Thanks” to the paid subscribers who currently don’t receive much “value added” for their paid subscriptions. NotebookLM doesn’t “ingest” web pages, so I was basically stymied for an reasonable way to add issues of Zero Retries to NotebookLM. But in some brief downtime the past couple of weeks, I did a specific enough AI and web query and found a reasonable way to do so. This will also address a longstanding task of porting out each issue of Zero Retries into a PDF so that it can be archived into DLARC.
  • Beginning the Zero Retries Zoom sessions (good name To Be Determined). In doing presentations for others, I’m not in control of the agenda (inclusion of Amateur Radio club business meetings, for example) and often, I feel that important (Zero Retries Interesting) information doesn’t get presented, or it’s diffused (discussion forks into discussing, for example, M17 in a presentation I intended to be about, for example, New Packet Radio. This is completely understandable in a context of a general presentation for an Amateur Radio club. I think there’s lots of room for a Zero Retries Interesting focused discussion / interview on specific topics with specific interviewees, and I’m determined to make that happen in 2026. Zoom does a great job in creating decent video, and I have hopes that either Zoom, or another application / service will make it possible for me to easily and efficiently edit the videos lightly (titling, minor cutting) and then post them on the Zero Retries YouTube channel. And, of course, it helps the “Zero Retries Synergy” that Zoom automagically creates a good enough transcript of each Zoom session.

    As with NotebookLM, Zoom sessions, at least at the basic tier that I’m currently using, the participation in a Zoom session has limits. Thus, as with the Zero Retries NotebookLM, this feature will be initially offered to Zero Retries paid subscribers. Again, that’s not a “shill” for additional Zero Retries paid subscribers, just a long overdue “Thanks” to the paid subscribers who don’t receive much “value added” for their paid subscriptions.

Thanks for a wonderful and productive 2025, all you Zero Retries readers!

Handy Tip - Use RSS to Monitor Groups.io Email Lists

A longtime Zero Retries reader mentioned to me:

Reading the Zero Retries email list via RSS is wonderful!

RSS is Really Simple Syndication, a way of monitoring blogs (mostly) and other websites that have an RSS feed, via a RSS feed reader app. My use of RSS is one of the main reasons I can bring you interesting developments here in Zero Retries (without spending most of my days manually polling various websites).

Indeed! That got me thinking that most of the Groups.io email lists that I follow for Amateur Radio, I’m doing so passively and thus don’t need to clutter my email inbox with each new post to the list (or digest). Groups.io allows you to be subscribed, but not receive emails which has the advantage of being able to go to the Groups.io page for the list and comment there if you wish. Gmail keeps nattering at me that I’m at 88% or so capacity on my current tier, and I’m going to implement this strategy in the next few days and set those Groups.io lists to “no email” and convert my monitoring to RSS.

Best of Zero Retries 2025

End of year summaries are the usual fodder for media such as Zero Retries, and I think that’s appropriate and useful for the first issue of Zero Retries in 2026. It was a busy and productive year for technological innovation in Amateur Radio.

(Likely) No Zero Retries on Friday 2026-01-09

I’m going to reserve the next ten days or so to complete the transition to a new publishing platform for Zero Retries without the self-imposed pressure to publish a new issue of Zero Retries. Thus I don’t plan to publish Zero Retries on Friday 2026-01-09 (or Friday 2026-01-02)… unless the conversion to the new platform goes really, really well.

Weekends (and Holidays) Are For Amateur Radio!

We’ve had a streak of clear (sunny) but cold weather here in Bellingham this week, and after publishing this issue, I’m going to reserve a few days to work in N8GNJ / Zero Retries Labs to catch up on at minimum, clear the bench of accumulated projects (perpetually in progress).

Have a great weekend, all of you co-conspirators in Zero Retries Interesting Amateur Radio activities!

Steve N8GNJ

Comment on ZR email list

ZR > BEACON

By Steve Stroh N8GNJ

Short mentions of Zero Retries Interesting items.

Introducing 44Net Connect: A Simpler Way to Access 44Net

ARDC website:

Are you a ham that wants to experiment with 44Net but found the setup process to be intimidating? Say no more, because we’ve got great news for you!

We’re excited to introduce 44Net Connect, a service that makes it easy for hams to begin using 44Net IPv4 addresses through a simple, modern setup. Whether you’re experimenting with digital modes, improving repeater infrastructure, setting up a home lab, or just curious to see what 44Net is all about, this new service lowers the barrier of entry to get you started.

Why 44Net Connect?

44Net Connect uses modern, secure networking technology (WireGuard) that’s already supported by many popular routers, including NETGEAR, TP-Link, and Ubiquiti, and it works across a wide range of devices, from desktop computers and phones to Raspberry Pis.

Here’s what makes 44Net Connect especially useful:Simple setup: No complex configurations required. Just connect and go!Get a static IPv4 address: Access a static 44Net IPv4 address without relying on your ISP.Bypass carrier-grade NAT (CGNAT) limitations: Perfect if your IPv4 support is behind CGNAT or has a short lease from your ISP.Experiment safely: You can experiment and learn without “breaking the Internet”– 44Net Connect has the bumpers in place for you.

All in all, 44Net Connect makes 44Net more accessible and fun, helping more people experiment with networking, amateur radio, and digital communications technologies!

How to Get Started

Getting connected is easy: all you need is a router, computer, phone, Raspberry Pi, or anything that can run a WireGuard client.If you haven’t already, go to the 44Net Portal, set up an account, and then open a ticket for call sign verification.Once your call sign is verified, head over to the 44Net Connect dashboard to sign up and join the registration queue.

From there, you’ll be able to explore what 44Net has to offer and see just how easy it is to get online.

A Community Effort

44Net Connect wouldn’t have been possible without the work and collaboration from Adam Lewis KC7GDY, who originated the concept; Zach Seguin VA3ZTS, an early contributor that worked closely with Adam on the project; and John Hays K7VE SK, whose subject-matter expertise and efforts were instrumental in bringing 44Net Connect to reality. Ian Redden VA3IAN, Dave Gingrich K9DC, and Dan Theisen WI7FI contributed valuable guidance, insight, testing, and support throughout the project as well.

We’d also like to thank the 2024 and 2025 Technical Advisory Committees (TAC), who helped shepherd this project from “what if” to proof of concept to being production-ready, and of course the many beta testers who provided valuable feedback along the way.

If you’d like to learn more about 44Net Connect or get involved, please reach out to Adam Lewis KC7GDY, our IT & Development Manager (adam@ardc.net) or John Burwell KI5QKX, our 44Net Program Manager (john@ardc.net).

A Nod to 44Net’s Legacy

44Net Connect debuted December 10, 2025, which is also the 45th anniversary of another pivotal moment in amateur radio, when Hank Magnuski KA6M put up the first digipeater in the United States and helped kick off the packet radio era. We are honored to mark this new service alongside a significant milestone in amateur radio and digital communications.

Join In!

44Net Connect continues the spirit of 44Net: a playground for experimentation and innovation with TCP/IP over RF. With this new service, getting started has never been easier. So fire up your router, and start exploring the possibilities!

My chosen router for 44Net Connect (not yet implemented) is the GL.iNet GL-AR300M16 (available from Amazon).

The article 44Net Connect is Live! in Zero Retries 0232 was an “insider’s heads up” notification on the 44Net email list. This is the formal, general, fully public article about 44Net Connect aimed at a more general audience.

I’m still jazzed that 44Net Connect is finally live and publicly available.

Comment on ZR email list

UberSDR - Open Source Web Based HF SDR

Andy Zwirko K1RA on the ka9q-radio email list:

… For those running the RX-888, there is a new system that is so cool I can’t put it into words. It wraps so much into one app I may be retiring many of my other go to SDR apps and hardware.

https://ubersdr.org/

https://github.com/madpsy/ka9q_ubersdr

It’s composed of two docker images to support KA9Q-Radio and another for the UI, decoding and processing. There are also standalone clients for Windows and Linux, which I’ve yet to play with that offer various audio and CAT interfaces and SDC TCI connectivity, something I’ve been looking to see supported in the opensource SDR realm. See

https://www.lw-sdc.com/

for more on add-ons.

I’ve spun up docker and when I’m not testing/playing/restarting the images, you can check the receiver UI here:

http://ubersdr.k1ra.us:9080/

but also check out some cool metrics and analytics at:

http://ubersdr.k1ra.us:9080/digitalspots_map.html

http://ubersdr.k1ra.us:9080/bandconditions.html

http://ubersdr.k1ra.us:9080/noisefloor.html

There are only a select few others running this found here:

https://instances.ubersdr.org/

To which Phil Karn KA9Q (creator of ka9q-radio) replied:

Pretty cool. This is exactly what I hoped would happen when I started ka9q-radio -- somebody would put a really good UI on it.

At a glance, this looks like an ideal Software Defined Receiver client - for Amateur Radio HF reception.

That merits a plaint - UberSDR supports only HF and on a specific (albeit, good) Software Defined Receiver, the RX-888, that’s only (well, mostly…) for HF.

A second, minor plaint - UberSDR has native installations for Linux (completely understandable) and Windows (also completely understandable), but not MacOS… also understandable, I guess. But this would be really cool running on a Mac given how much Graphic Processor Unit (GPU) power that a typical, modern Mac has available (and almost entirely idle) in the era of the Apple M4 processor that is now baseline on current generation Macs.

We need the kind of functionality and usability such as UberSDR for VHF / UHF SDRx units, especially building in the decoders for common VHF / UHF modes, such as the various flavors of digital voice, conventional packet radio / APRS, LoRa / Meshtastic (on 433 / 868 / 915 MHz), etc.

“Need”, as my observation is that HF operation is mostly of interest to Amateur Radio Operators with long experience, but not of much interest to NewTechHams who are often constrained to VHF / UHF operations in apartments, condos, housing developments governed by Homeowners Agreements (HOAs) prohibiting external antennas, etc. This matters if Amateur Radio is going to be able to be seen as relevant in this era amongst the potential population that could become NewTechHams.

Comment on ZR email list

Electronic Technicians Association International

As an Electronic Technician (now retired), I had always intended, but never quite got around to getting certifications by the International Society of Certified Electronics Technicians (ISCET). That didn’t hinder me in my eclectic career path which expanded into SysAdmin / NetAdmin work, and eventually writing… but it was always something that I regretted not doing.

In researching a related area for an idea and possible story, I discovered that ISCET merged with other organizations with similar missions into the Electronic Technicians Association International (ETAI).

ETAI even has their own electronic magazine - High Tech News.

Wikipedia’s article - Electronics Technicians Association gives a good overview of the history of the various organizations that merged to become ETAI.

This mention in the Wikipedia article was Zero Retries Interesting:

In 1993 ETA became a COLEM for the FCC Commercial Radio License program and offers professionals the chance to sit for seven different FCC commercial licenses at ETA test sites including the general radiotelephone operator license.

I was under the (mistaken) impression that FCC licenses for individuals (other than Amateur Radio and General Mobile Radio Service - GMRS) had long since been deprecated in favor of industry certifications. Apparently the FCC Commercial Radio Operator Licenses continue, but testing for it is administered by Commercial Operator License Examination Manager organizations (COLEMs) such as (per ChatGPT):

  • National Association of Radio and Telecommunications Engineers (NARTE)
  • W5YI Group
  • National Radio Examiners (NRE)
  • ATI / FCC Commercial Radio License Examinations

It would be cool if something could be worked out with one of those groups, perhaps W5YI group (given its origins in Amateur Radio) to create “certifications” for various aspects of Amateur Radio in the 21st century such as:

  • Software Defined Radio
  • APRS
  • Digital Voice systems
  • Antenna theory
  • Microwave communications

And many other specialized topics.

Comment on ZR email list

Pending ARRL Book - Digital Networking for Ham Radio

This email from ARRL to some (ARRL affiliated?) Amateur Radio clubs was shared with me by Zero Retries reader Bob Houghton AD6QF:

While doing some research on clubs that have members with interests around new technologies like AREDN, Meshtastic, and networking, I thought you and the executive team of [organization redacted] would be interested in a new ARRL book called Digital Networking for Ham Radio, which is expected to be available before spring 2026. We go to press officially in mid-January. Here is a link to the final high-level table of contents.

Glen Popiel, KW5GP, an accomplished author of multiple ARRL publications, brings a unique perspective to this new book. Its focus stands out, and it is worth recognizing both individuals and clubs that are engaged in these subjects. Innovative technologies in the 33-, 23-, 13-, and 5-centimeter bands are attracting commercial interest. This book highlights the amateur radio community’s engagement with these frequencies and why we must show we are using them to prevent commercial interests from taking them away from the amateur radio community.

The new book will include pages for “booster” ads, so individuals and clubs interested in these topics can take part. Here are the details:

Individuals — For $30, an individual will have first and last name plus call sign listed in the book. Individuals listed will also receive a free printed copy of the book as a thank you. Those on our list will receive a discount code to claim a printed copy as soon as it arrives in our warehouse.

Clubs — We believe that the more club members who have this book, the more it will spark discussion and encourage even greater hands-on group projects. Listing the club’s name, main call sign, and website address costs $50. Club members who are not named individually are eligible to buy the book at half price. There is no limit to the number of copies you can order.

We expect to fill six to eight pages with booster ads in this book on digital networking and their use of the microwave spectrum. With a list price of $34.95, this book is an excellent way to support an important topic, demonstrate your commitment, and help defend our spectrum as one of our boosters.

Time is extremely limited before we go to press. Submit your club details using the online form linked below. We encourage you to share this message with your members or those interested in this topic so they can be part of the individual listing option.

The ARRL member services team will then reach back out to confirm the details and to process payment.

We need to close all form entries by January 9, 2026, to prepare and complete everything for the first production run.

Here is the form link.

Please do not hesitate to call or email me directly with any questions.

73,

Steve Bossert, K2GOG
Advertising Sales Manager
ARRL The National Association for Amateur Radio®
225 Main Street, Newington, CT 06111-1400
860-594-0203
sbossert@arrl.org
ads@arrl.org
www.arrl.org





AD6QF said:

I take this as a positive sign that ARRL is moving in the right direction.

I agree!

I think that the “booster” (I’d call it sponsorship) section of the book is a great idea, though I think they slightly missed the mark by not offering a slightly more prominent mention (such as mentioning the company name in a bold font), at a higher cost, to commercial companies. It’s an interesting hybrid to the complications of crowdfunding via Kickstarter, etc. where a product must be delivered. This approach is such a good idea that I’m going to adopt it for my upcoming book.

To support this book, and ARRL’s re-entry into books about Amateur Radio data networking (there have been a number, most recently High Speed Multimedia for Amateur Radio in 2016), I queried K2GOG at ARRL about the possibility of Zero Retries being mentioned as a “club” in the book, and I received a positive response, details To Be Determined.

I agree that this new book is a positive sign for ARRL’s recognition that Amateur Radio in the 21st century won’t be Same Old, Same Old technologies, and that Amateur Radio data networking is a significant trend in the 21st century. I hope I’m wrong in inferring that the book will posit that “Amateur Radio data networking is only being done in “33-, 23-, 13-, and 5-centimeter bands” and not mention the innovation in data networking that is being done in Amateur Radio VHF / UHF bands such as VARA FM, New Packet Radio, IP400, CATS, and AREDN (in the 902-928 MHz / 33 cm band).

Back in 2025-08, when I first heard about this book, I corresponded briefly with KW5GP with some suggestions of topics I think the book should include, and pointers to a number of Amateur Radio microwave networks.

To answer a question in advance, no this book doesn’t impact my plans for, or intended content of my pending book Zero Retries Guide to Amateur Radio in the 21st Century. While I think there will be some overlap of coverage, the two books have different aims and intended audiences. For example, I have no qualms about including speculative ideas (clearly labeled as such) such as my SuperPeater concept and discussing the rise of NewTechHams, and what that demographic portends for Amateur Radio in the 21st century.

I look forward to buying this book, reading, and learning more about the covered subjects from KW5GP’s perspective.

Comment on ZR email list

Ham Radio Workbench Podcast 252 - AllStar ROIP Linking with David NR9V from AllScan

I haven’t yet listened to this episode of HRWB, but it is next on my podcast list, within the next few days. I’m in awe of the productivity of David Gleason NR9V in churning out a wide variety of innovative audio interfaces via his company AllScan.info for a variety of use cases and radios in Amateur Radio. He's created several new variants of his products just within the last few months, which he previews on the Facebook group AllScan AllStar App & Nodes.

An episode of HRWB like this doesn’t get much more Zero Retries Interesting, and I really want to hear what NR9V has to say, especially from his encyclopedic knowledge of AllStarLink, which I could use a primer on.

Comment on ZR email list

DreamHat+ 60 GHz RADAR Hat For Raspberry Pi

Robb Smith VE7PSK via email:

Have you seen the DreamHat+ 60 GHz radar hat for Raspberry Pi?
(https://linuxgizmos.com/dreamhat-enables-60-ghz-radar-sensing-on-raspberry-pi-4b-and-5/)?


This is a computer-controlled 60 GHz transceiver in the form of a Raspberry Pi HAT which can be had for relatively little money, and looking at the datasheet, I think it might be possible to use it as a high-speed data transceiver. The 60 GHz band is an ISM band, so it should be possible for hams and non-hams alike to have some fun with it.

The article says in part:

Dream Boards has released the DreamHAT+ Radar, a compact add-on board that brings high-precision 60 GHz mm-wave radar capabilities to Raspberry Pi 4B and 5. Built around Infineon’s BGT60TR13C radar chip, the DreamHAT+ is designed for developers and researchers working on gesture recognition, presence detection, indoor tracking, and privacy-focused sensing, all without relying on cameras or microphones.

The radar operates between 58 and 63.5 GHz using frequency modulated continuous wave (FMCW) technology. It features one transmitting and three receiving antennas on a single chip, enabling directional sensing and motion tracking.

…

The DreamHAT+ Radar is available now for $110.83 from Pimoroni.

Two decades ago, the cheapest 60 GHz unit available was (from fallible memory) tens of thousands of dollars, which was reasonable at the time for achieving 1 Gbps radio links rooftop to rooftop in urban areas. Much of the expense of those units was creating an antenna that could focus (and track) a beam with the wavelength of 5mm.

Now a 60 GHz radio is a cheap Raspberry Pi HAT. I love technology!

Comment on ZR email list

Pocket Pico / Pico TNC Project

Peter Filiberti KF7PSM via email:

I saw the write up on the OPENTNC. The author also modified the code to
work on our hardware design for the "POCKET PICO" as it is dubbed by our
group.

You can find it here:
https://github.com/pfiliberti/pico_tnc

Also another Ham forked our repo and took our firmware and made some
slight changes so it runs on the opentnc hardware. That is located here:
https://github.com/mpvano/pico_opentnc

Something else that might be of interest is the original tncemu:
https://github.com/pfiliberti/tncemu











From the PICO TNC page:

PICO TNC is the Terminal Node Controller for Amateur Packet Radio powered by Raspberry Pi Pico. This is a fork of that project. I have removed all of the major features of the code except for the modulator/demodulator section and inserted a z80 emulator from my TNCEMU project that emulates a Heathkit HK21 Pocket Packet. Introductory Video can be seen here:

Read more