One of the most sought after substances in the Universe is water – especially in...Zero Retries is an independent newsletter promoting technological innovation that is occurring in 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 fourth year of publication, with 2000+ subscribers.
Request To Send
Commentary by Steve Stroh N8GNJ
Playing for “Those Five”, Microcomputers in 1976, Linux… and the M17 Project
Steve Stroh N8GNJ
Followup to The LEO Satellite Industry Needs More Engineers
Witold Kinser VE4WK and Steve Stroh N8GNJ
What’s New at Digital Library of Amateur Radio & Communications - August 2024
Kay Savetz K6KJN
Web version of this issue - https://www.zeroretries.org/p/zero-retries-0165
Commentary by Editor Steve Stroh N8GNJ
My thanks to William Arcand W1WRA for renewing as a Founding Member Annual Subscriber to Zero Retries this past week!
My thanks to Prefers to Remain Anonymous 10 for renewing as an Annual Paid Subscriber to Zero Retries this past week!
My thanks to Prefers to Remain Anonymous 43 for becoming a new Annual Paid Subscriber to Zero Retries this past week!
My thanks to the many Monthly Paid Subscribers to Zero Retries!
Financial support from Zero Retries readers is a real vote of confidence for continuing to publish Zero Retries.
Just recently, paid subscriptions that provide financial support of Zero Retries has enabled me to fund the m17-users email list (beyond the 100 max subscribers of the free tier) for promotion of M17 as a working, usable system that is no longer solely a loose collection of related projects.
Wow… Now in its fourth year of publication, Zero Retries has 2000+ individual email subscribers. Anecdotally, hundreds more people read Zero Retries via RSS feed and from mentions I post every week to 293 followers on Mastodon (n8gnj@mastodon.radio), and 23 followers on Bluesky (@n8gnj). There are a fair number of folks who, on principle, won’t subscribe to Zero Retries because it’s currently hosted on Substack, with all the baggage of that platform (heard, and understood).
This latest big bump in subscribers past 2000 is mostly from yet another generous mention in Amateur Radio Weekly Issue 343 on 2024-08-10 by Editor Cale Muth K4HCK:
Why M17 is significant
No other Amateur Radio digital voice system is as well defined as M17.
Zero Retries
That article is now, retroactively, edited to be Part 1. Part 2 appeared in last week’s Zero Retries 0164.
… a big part of the energy of Zero Retries is generous mentions like this one from Michael Clemens DK1MI on his blog:
Zero Retries
2024-08-11
"Zero Retries is an independent newsletter promoting technological innovation in Amateur Radio, and Amateur Radio as (literally) a license to experiment with and learn about radio technology." This is how Steve Stroh (N8GNJ), the editor of Zero Retries, describes his weekly newsletter.
But to call it just a newsletter does not do justice to his work. I have been reading and following this site for a long time and am always fascinated by how many high-quality articles he publishes every week. Steve doesn't just limit himself to writing news but is obviously very interested in promoting the hobby of amateur radio and conveying its fascination. Important projects such as the M17 project are regularly pushed by him in order to help drag this valuable project out of its niche.
In the meantime, the newsletter has reached a size that would justify publishing the content as an ePub (hint hint). I would actually love to read it on an eBook reader.
My recommendation? Click here, subscribe and have a nice weekly read on inspiring amateur radio related topics.
First, thank you for the kind words DK1MI! An ePub version for eReaders… hmm… I had not previously considered that, but that does make sense, and fits with a few other long term plans that are in motion for Zero Retries.
DK1MI is a bit modest in not mentioning his (perhaps unintended) role in creating Zero Retries Interesting content himself, including excerpts here in Zero Retries:
Zero Retries 0110 - A Declaration of Love to Amateur Radio
Zero Retries 0152 - Open Source in Amateur Radio Wiki
Zero Retries 0158 - Open Source in Amateur Radio Wiki
Zero Retries 0162 - The Beauty of Keyboard to Keyboard Digi Modes
Zero Retries 0164 - The QubeDX - a modular CubeSat style QRP Transceiver
DK1MI’s Open Source In Amateur Radio Wiki - opensource.radio - is a perfect example of why I started Zero Retries. That wiki is a great project1 to try to gather a quick mention of all (eventually… it’s a work in progress) open source projects in Amateur Radio so, for example, if you want to find an open source project for (imaginary) a 68092-based packet radio modem… this would be a great place to start one’s search.
If one’s only source of Amateur Radio news is the “mainstream” Amateur Radio media, likely you wouldn’t ever hear3 of the Open Source In Amateur Radio Wiki. Which is just… not… cool… considering that a lot of new Amateur Radio Operators are coming into Amateur Radio from younger, techie, hacker / maker communities and the Open Source In Amateur Radio Wiki is something that they will find extremely valuable in adapting Amateur Radio to their priorities of what a radio-based technical activity should be.
But DK1MI, like Zero Retries, publishes technical content in public, for the benefit of Amateur Radio worldwide and I’m happy to promote such material, and a lot of other great material (that I’m not writing - I’m just mentioning). If there wasn’t all of this Zero Retries Interesting activity going on, or there was extensive coverage of technological innovation in Amateur Radio in the “mainstream” Amateur Radio media… there wouldn’t be a need for Zero Retries. So, thank you DK1MI, but do take a bow yourself.
Another thing that keeps Zero Retries going is the incredible support I get from my wonderful wife Tina Stroh KD7WSF. Tina getting her Amateur Radio license (to satisfy a premarital promise, deferred for a couple of decades) is an epic tale worth telling sometime. The salient point is that Tina has put up with me… supported me… for 40 years of marriage now (as of Sunday 2024-08-18). Tina has encouraged me beyond belief in taking a great leap of faith a couple of decades ago from a paycheck job to trying to make a living as a freelance writer (didn’t go so well…) and now in making Zero Retries a success for three plus years now. Recently Tina has taken on the role of Office Manager for Zero Retries, tackling some of the nagging administriva that inevitably has to be dealt with when there is a pro forma business with minor revenue involved, which frees me up to write. Thank You Honey, and…
Happy Anniversary Honey!
Zero Retries is also picking up new subscribers from Facebook. My wife Tina KD7WSF told me about the Facebook group Friendly Amateur Radio Elmers which she had been participating in, and suggested I join. It is indeed a friendly group, and I occasionally contribute there when I think I can add some unique perspective (generally, digital topics). The moderators do a pretty good job of enforcing “friendly” in the group, though there are the inevitable folks that test the limits. One behavior that’s expressly forbidden is the semi-snarky default reply to a question with “Google is your friend”. That consistently provokes a fast response from the moderators. There are a lot of beginners and folks with unique situations that request specific types of help, and this is one of the few Facebook groups about Amateur Radio that seems to work (again, mostly from hard work by the moderators).
Also in Amateur Radio Weekly Issue 343, K4HCK also generously mentioned the Store and Forward Podcast by Kay Savetz K6KJN and I.
Store and Forward
A podcast about the past and future of Ham Radio.
Store and Forward
… all three four episodes of it to date 😀
Episode 4 features Kay telling his most recent “away team” story of rescuing (literally) unique electronic material as part of the mission of Digital Library of Amateur Radio & Communications. Now that we have a shiny new website (thanks again K6KJN), Store and Forward is now mentioned in the Closing the Channel section at the end of every issue of Zero Retries. Kay tells the tale, in more detail, in text, in his article in this issue of Zero Retries.
JARL Ham Fair 2024 in Tokyo, Japan on 2024-08-24 and 25, next weekend!
Pacificon 2024 in San Ramon, California, USA on 2024-10-18 thru 20 in 9 weeks. Tina KD7WSF and I plan to attend Pacificon 2024 (which makes it “major” to us). I have offered to do a presentation about Technological Innovation in Amateur Radio, and (I think) my proposal has been accepted.
See the Zero Retries Guide to Zero Retries Interesting Events for additional events.
Several Zero Retries Interesting Events have occurred recently such as AirVenture 2024, Central States VHF Society, and the EME Conference. I would love to hear reports about those and other recent Zero Retries Interesting events for reporting out to the readership of Zero Retries. An email is fine, or if you’d prefer to write an article, I’m happy to lightly edit it if requested.
Note that I didn’t ask for a report for DEF CON 32 as Zero Retries Pseudostaffer Dan Romanchik KB6NU did a great job reporting out from that conference - DEF CON 32: Another mind-blowing experience.
Zero Retries now sponsors some email lists for in-depth discussion of topics that I haven’t seen addressed by other email lists or forums.
new-dcc - Discuss the creation and operation of a conference similar to the long-running Amateur Radio Digital Communications Conference that was formerly sponsored / managed by ARRL and TAPR. I had intended that this would get a fair amount of attention so that there will be a DCC of some kind in 2025, but my attention is going to be deferred for a few months by…
902-928-threat-2024 - Discusses that NextNav, Inc. has proposed to the FCC to reconfigure the usage / allocations of the 902-928 MHz band which is shared between license-exempt (Part 15) users and Amateur Radio users. Despite NextNav's "assurances" to both of these user bases that they won't be significantly impacted by NextNav's proposal. Make no mistake - this proposal would severely impact both license-exempt use and Amateur Radio use of 902-928 MHz. I created this group to attempt to provide some “cross fertilization” between groups of users of 902-928 MHz that otherwise wouldn’t be cooperating in their comments to the FCC. This is an experiment, but it seemed worth a try and the threat is significant, and urgent as NextNav asserts that it has priority in 902-928 MHz and thus it’s “reasonable” to reconfigure the band per its request.
m17-users - Discuss using M17 Project technology to build out infrastructure to support M17 (such as repeaters) and the discussion of using M17 devices such as radios, adapters, Internet linking, Software Defined Transceivers (and receivers) etc. m17-users was operating as a free Groups.io email list with a max of 100 subscribers. I’ve now upgraded m17-users to a paid email list and thus it can now accept more users (up to 500 now). m17-users is sponsored by Zero Retries ($20 / month). My thanks to Steven Davidson K3FZT and M17 Project for donations for the first month of operation.
Dale N0KQX comment on Zero Retries 0164:
The military put all theirs eggs in the satcom basket for a while and realized that wasn’t a good idea and reinvested in some hf radio.
I replied:
Dale - Yep - I saw a fair amount of what I guessed was HF whips on DDG 102. It's no panacea though - HF can be jammed fairly easily. Hmm... you just gave me an interesting idea for a Zero Retries article next week - Thanks! I'll credit you.
As N0KQX observed, “HF is back” in military communications, and I’ll guess that it needs ideas for good, reliable, HF communications beyond the expediency of 10 kW transmission power from ships and shore stations.
What if there was a contest on Amateur Radio HF where the communications were encouraged to be stealthy and reliable as an example of the ingenuity of Amateur Radio Operators? Just a few ground rules (and, again, as I propose this, such a contest is completely imaginary… at the moment):
The contest runs for only 6 hours or so - long enough to prove out the concept, but not long enough to disrupt any significant Amateur Radio activity.
The 30 meter band seems like a good place to conduct this contest.
The contestant has to establish a connection over HF with another station at least 1000 km away. (The assumption that there will be pairs of operators using the same experimental system.)
The contestant has to pass at least 1 MB of data another station during the duration of the event. The data transfer does not have to be continuous. For reference, VARA HF “Tactical, Level 17” can transfer up to 8489 bps, which would require (by my math) ~ 16 minutes to transmit 1 MB of data (not counting acks and retransmissions, etc.).
The transmission has to be identified with the callsigns of the two stations (in-mode is acceptable).
The experimental mode has to be publicly documented on a website, with contact information.
After the contest, all of the participants disclose their participation on a common website.
Adding some interest to the contest, perhaps there could be several geographically dispersed Software Defined (Web) Receivers that record the entire band during the contest for later playback / analysis.
The idea is that the military doesn’t have to transmit back into Amateur Radio spectrum, but they can monitor the activity of the contest. If they observe a system that looks interesting, they could contact that station for more info.
The “best case scenario” in such a contest would be that the military was monitoring… and didn’t detect that a particular experimental system was actually in use, but it was proven that it was in use and moved a significant amount of data.
Prior to the creation of WSPR and the other WSJT-X modes, it wasn’t well-understood that such communications were possible on HF, with signals so far below the noise floor. Now we know that such things are possible, and we’ve got more cheap computer power than ever to use in implementing even more impressive modes.
And… I’m not counting out the potential for Artificial Intelligence / Machine Learning techniques to create (and operate) such new modes.
Lastly… on this happy (for Tina and I) and sunny weekend, I just had one of those “living in the future” moments. Our daughter and son-in-law have two cute, young cats (our Grandkittens). She regularly sends us short video clips which we always enjoy. As I was finishing up this issue of Zero Retries, I happened to be away from my phone when one video clip arrived, but my watch was within range of my phone, so I was notified. Absentmindedly I tapped on my watch to acknowledge, and the video started playing… on my watch4… complete with audio!
To someone like me that grew up with no personal computers, to progress to this marvel of technology, within one lifetime, really does feel to me like we are living in the future5. Thus how can I not have that same sense of wonder and optimism about this most futuristic of hobby activities - Amateur Radio, where we actually get to participate in making the future such as M17 and other bleeding edge radio technology projects?
73,
Steve N8GNJ
By Steve Stroh N8GNJ
This first section is a story that I include in the Thank You email to paid subscribers to Zero Retries who choose financially support Zero Retries, despite no extra benefits (to date) for doing so, other than my additional attention to them when they email or call. I think it helps frame the situation in Amateur Radio between those that get M17, and those that don’t get M17.
One of my “virtual mentors” in becoming a writer and starting Zero Retries is the late microcomputer pioneer and author Don Lancaster. One of the most profound things (to me) that Lancaster has ever written was this brief passage that he only ever mentioned a few times:
Many years ago, I was at a rock concert. The opening act was a single flute player standing solo in front of the closed stage curtains. His job was to warm up the audience for the high priced talent that was to follow. He was good.
But as he went along, the musical vibes got stranger and stranger, then totally bizarre. He was playing chords on his flute. Combined with utterly unbelievable riffs. Much of the audience got impatient and bored at what seemed like a bunch of gawd-awful squawks.
Then I happened to notice a friend beside me who had both been in and taught concert band. He was literally on the edge of his seat. He turned to me and slowly said “you ...can’t...do...that...with...a...flute”.
Of the thousands and thousands of people in the theater audience, at most only five realized they were witnessing a once-in-a-lifetime performance of the absolute mastery of a difficult and demanding instrument.
Always play for those five.
This passage just resonated with me, and in starting Zero Retries, I decided that I was going to write for “those five” and not attempt to write Zero Retries for a mass audience. Rather, I would embrace Lancaster’s advice and write for “those five” that shared my enthusiasm for technological innovation in Amateur Radio and the role that Amateur Radio can play in advancing technological progress by exposing people to hands-on radio technology and potentially influencing young people into careers involving radio technology. We need them now, and we’re going to need a lot of them in the future. Hopefully Zero Retries can help do so, at least in a small way.
Thus I write Zero Retries for “those five”, and I’m humbled that there are a very few of you who chose to step up to be Founding Members and Paid Subscribers to indicate your substantial support for what I’m doing in Zero Retries.
…
Writing about the potential I see in M17 is part of writing for “those five” (well, 2000+ of you now…). In having written extensively now about M17 Project and its role in Amateur Radio, it’s become apparent to me that there is a very pronounced schism regarding M17 versus other VHF / UHF digital voice systems.
The majority of Amateur Radio Operators don’t understand what the fuss is about M17.
The majority of Amateur Radio Operators generally get that Digital Voice on VHF / UHF is somewhat superior in some ways to “plain old FM”, and have bought into one of the three variants of VHF / UHF digital voice - Digital Mobile Radio (DMR), D-Star, or System Fusion (SF)… and having made their choice of one of those three, call it good. The majority of Amateur Radio Operators don’t see the point of yet another variant of VHF / UHF digital voice.
But, to a minority of Amateur Radio Operators… which in my observations are the newer Amateur Radio Operators who trend younger, techie, and proudly count themselves as part of the Hacker / Maker community… DMR, D-Star, or SF were never an option because they aren’t open (or at least weren’t all the way open). In fact, in several private email threads with me, some folks have told me that they weren’t interested in Amateur Radio at all… until they learned about M17 and that it’s open. Having learned that M17 was an option… then they became interested in Amateur Radio.
M17 is a very big deal to them because it’s entirely open. There’s no trademark or copyright on the name. The specification is open. The hardware designs are open. The software designs are open. The Internet interfaces are open. The critical CODEC for converting analog voice into an efficient data stream and back into voice is Codec 2, not proprietary like every other VHF / UHF digital voice system. In a phrase, M17 is their kind of Amateur Radio because M17 is open.
I think this hypothesis is being proven out by the experiences Dan Romanchik KB6NU is having at various “hacker” conferences this Summer - HOPE, and most recently DEF CON 32 - DEF CON 32: Another mind-blowing experience. KB6NU is exposing younger, techie, hackers and maker folks to Amateur Radio in a way that is relevant to them, and they quickly become interested. Hacking? Radio? Together you say? Thus they become licensed at the VE session at the same conference.
Thus… there’s a very real schism between the “open, schmopen” majority, and the “if it ain’t open, I’m not goin’” minority.
I offered an analogy about M17 versus proprietary Amateur Radio digital voice systems on the m17-users email list - 1976 and M17:
M17 versus the status quo of Amateur Radio digital and FM repeaters is analogous (in my mind) to the computer industry in 1976.
In 1976, mainframes and minis were doing the job satisfactorily for the computer industry. Everyone that needed and could afford a computer had one. That’s analogous to the current repeater technology and the current repeater owners.
But in 1975, one year earlier, microcomputers had come on the scene. The MITS Altair was unveiled in the January 1975 issue of Popular Electronics magazine. By 1976 a completely new crowd entered the “computer industry” and were using these new (and still very imperfect, by mini and mainframe standards) microcomputers to do computing very differently than was possible with mainframes and minis.
The microcomputer folks didn’t ask “permission” from the mainframe and mini folks, and they didn’t try to persuade the mainframe and mini owners that microcomputer were “better” and they should start doing / using microcomputers.
Instead of asking permission or trying to persuade, they just started doing things their own new way with microcomputers and rapidly evolved an entirely different version of the computer industry.
A decade later, the mainframe and mini computer industry looked around and said “what happened?!?!?” All of the energy in the computer industry had shifted to microcomputers.
…
In my opinion, from deep observation of M17 and trying to explain it and write about it substantively…
M17 in 2024 is at the “computer industry circa 1976" point of inflection.
Like microcomputers, M17 is open. Thus there’s no structural issue that prevents M17 from rapidly growing and evolving.
As good as an analogy as I thought that was… Cale Mooth K4HCK offered a far better analogy, from his generation’s perspective:
For the post-minicomputer generation, the relevant genX analogy will be that of Linux vs. Windows. Linux offered the same open source freedom that M17 does today in that it was a completely accessible, modifiable, and “free” alternative to Microsoft that we could tinker with. Today, almost every server on the internet runs Linux. If the M17 future follows that path, we'll see a ubiquitous mode found on nearly every transceiver. And people won't really think about it.
It's exciting to me as a “techie” because it can be entirely a software interaction. The intersection of software and RF is what got me interested in the hobby, and this extends that world of freedom and possibility.
People will be persuaded to invest in M17 once they can see the benefits over other modes in practical application. That will come as the early adopters continue to build on this initial success and showcase what's possible.
K4HCK is of the generation that matters in this discussion - they’ve got decades ahead of them to contribute to Amateur Radio… or not, if they aren’t convinced that Amateur Radio offers their generation opportunities compatible with their interests and priorities.
So… yes, thank you so much K4HCK for this far better analogy to explain the open nature of M17 and why it matters - as much as Linux being open versus Windows not being open matters.
I’m a bit more skeptical than K4HCK of the “build it and they will come” approach of evangelizing and building out M17 systems will entice more users (beyond the “you had me at open and radio technology” folks… at least through the end of this decade. I don’t think that M17 quite represents a “TNC-2” moment in Amateur Radio where the TNC-2 offered something that didn’t exist before it. From my perspective, most Amateur Radio Operators see digital voice on VHF / UHF to be an (over) solved problem with DMR, D-Star, and SF.
Thus I don’t think this schism can be bridged. My experiences to date have led me to believe that it won’t be very effective to evangelize M17 as an alternative to the other digital voice systems. I think the “I just don’t get it about M17” contingent in Amateur Radio is just going to have to be routed around by the folks with the energy, the better M17 technology (which will evolve faster and take advantage of new computer and radio technology)… and the youth to outlast the majority.
Instead, I think the M17 community should put our energy into extending M17 such as adding digital signatures, building out new M17 infrastructure, assisting new M17 users that are really interested in getting on M17, creating new devices, and evangelizing to the younger, techie, hacker / maker folks that would be receptive to “hack with radio technology - get your entry level Amateur Radio license and start playing with M17 and other open systems in Amateur Radio”.
I can easily imagine setting up localized M17 repeaters that cover perhaps a college campus, that will probably get more use with data / messaging than digital voice. How to set up such an M17 repeater will be a big focus of the M17 book that I’m working on.
This is an email from Witold Kinser VE4WK in response to two mini-articles in Zero Retries 0162:
Calculated Ignorance of Amateur Radio (Request To Send)
The LEO Satellite Industry Needs More Engineers (ZR > BEACON)
As VE4WK acknowledges, there was no hint of Amateur Radio involvement in the article cited by KB6NU, and later my mini-article. Apparently that omitted mention of Amateur Radio is now considered to be an oversight.
Thank you for Zero Retries and LEO SatS
Dear Steve,
Thank you very much for your effort in delivering an excellent Amateur Radio newsletter. I always find something very interesting in each issue.
In Zero Retries 0162 (Beacon), you mentioned an article "The LEO Satellite Industry Needs More Engineers," by Kathy Pretz in IEEE Spectrum Online (2024-01-07) that describes our IEEE Future Directions LEO Satellites and Systems (LEO SatS) Initiative, but did not mention amateur radio (AmRad) explicitly. I agree, it was a significant mistake. I apologize.
My apology also goes to Daniel M. Romanchik, KB6NU, who alerted you to the IEEE Spectrum article in his KB6NU Ham Radio Blog.
However, I assure you that we use ham radio bands to operate our satellites. I started designing, building and testing 3U Cubesats in 2010 with 130 students and 70 advisors from academia, industry, business, military and governments. Each generation takes two years to complete. Many university/college students have become certified ham radio operators through my course on amateur radio theory and operations. My new AmRad Basic Qualifications course will start in January 2025. I also taught Advanced and Morse Code courses. Many of those students are now in leading positions in the aerospace industry. So, amateur radio has been at the centre of all our activities.
The IEEE LEO SatS Initiative is preparing student competitions to develop new subsystems and algorithms for the nanosatellites to improve communications between the satellite and the terrestrial federated networks through two-level undergraduate and graduate student competitions.
An experienced ham and the Operations Lead of the IEEE MOVE Team (https://move.ieeeusa.org) is an advisor of the LEO SatS.
We are also preparing an interesting and free-of-charge sixth workshop on LEO SatS this November. If you wish, I could send you information on the topics covered so that you could include it in the Zero Retries Newsletter.
Another LEO SatS development that might interest the AmRad community is a series of workshops on CubeSat and CanSat development using inexpensive kits. The workshops will address improvements and even new approaches to data communications on AmRad bands.
Kind regards,
Witold VE4WK
My thanks to VE4WK for his kind words and such a gracious followup to a mildly critical pair of mini-articles. One of the best parts of publishing online is that you can fix issues like this. Those two mini-articles in Zero Retries 0162 now have a pointer to this article so future readers of those mini-articles won’t be left with the wrong impression.
In the bigger picture, as VE4WK describes, there is significant crossover between Amateur Radio and the work of the IEEE (Institute of Electrical and Electronics Engineers) in reaching out to students to encourage becoming an Electrical / Electronics engineer. IEEE’s “public” publication, IEEE Spectrum does a good job in exposing some Amateur Radio activity to its membership that otherwise might not be aware of Amateur Radio (and doing fun stuff with radio technology).
But it seems odd that there isn’t a more formal involvement between IEEE and Amateur Radio… perhaps even a Special Interest Group within IEEE specifically to encourage more technical Amateur Radio activities.
For example, an interesting overlap between IEEE’s activities and Amateur Radio is the development of the IEEE 802.11ah Wireless Local Area Network standard. 802.11ah, and the tightly related Wi-Fi Alliance certification for Wi-Fi HaLow seems poised (in my observation) for significantly increased usage of the 902-928 MHz band in the US, which is shared between unlicensed uses such as 802.11ah / Wi-Fi HaLow and Amateur Radio.
An IEEE SIG for Amateur Radio… (again, just fantasizing)… that would be cool, and of course, Zero Retries Interesting!
By Kay Savetz K6KJN
Zero Retries Pseudostaffer
Internet Archive's Program Manager, Special Collections
Hello from — not DLARC World Headquarters as usual, but from 30,000 feet somewhere over the midwest United States. I’m headed back to HQ following a successful field trip to collect radio books and manuals for the Digital Library of Amateur Radio & Communications. With that in mind, this column will be less “What’s New at DLARC” and more “What I Did This Summer.”
Months ago, I read in Amateur Radio Weekly that Fair Radio Sales, a radio surplus store in Lima, Ohio, would be closing. After running the place for more than 40 years, the proprietor Phillip Sellati is ready for a well-deserved retirement. I reached out to Phillip to ask if he would donate leftover radio books and manuals to DLARC. He agreed. Flash forward to last weekend, when two assistants and I arrived at Fair Radio’s massive warehouse in beautiful Lima. Phillip gave us carte blanche to take everything we wanted for DLARC.
I can hardly express how large this warehouse is and how much reading material was available for us: commercial radio manuals. military documents, avionics repair guides, parts catalogs, schematics… on shelves and in stacks and filling up filing cabinets. It took our three-person team two ten-hour days to box it all up. I rented a U-Haul van and drove the material directly to Internet Archive’s scanning center, about an hour and a half away in Fort Wayne, Indiana. In two round trips I delivered about 200 boxes of radio reading material to the scanning center.
When I needed a little break from driving and boxing up manuals, I took a few minutes to explore the massive warehouse. Soooo many radios and gear, literally stacked to the rafters. I noticed once-upon-a-time top-of-the-line Kenwood ham gear and military radios seemingly going back to WWI. All guarded by a very good old dog named Reagan. You can see some pictures from the trip (yes, including Reagan.)
Fair Radio was among the last of the great surplus places. Check out their web site while you can. We at DLARC are deeply grateful to Mr. Sellati for his generous donation of material. He was especially kind in giving us access before everything else went to auction August 15-17.
The scanning center will start on the Fair Radio material soon, but it will certainly take them months to get it all done, interspersed with their other scanning work. I’ll keep you updated as their work progresses.
The expedition to Fair Radio was actually my second away mission for DLARC this summer. In July, I flew to Denver to sort through the collection of Robert Cooper. This time, I was on my own, digging through seven pallets of material from the estate of Mr. Cooper. He was a ham, but was primarily known as an expert in satellite and cable TV communications. In the ‘80s, he was one of the first people to figure out that HBO transmitted its satellite signals unencrypted. He published an article about how anyone could set up a satellite dish in their backyard to get free TV. These ideas led to an entire industry of TVRO (television, receive only) satellite dishes, lawsuits, and a years-long escalating war of scrambled signals and television descramblers. That whole story arc is well-documented by the various print publications and television programs that Coop produced.
So there I was in a warehouse in Denver, trying to get a grip on all that material. Magazines and books and videotapes, but also decades of personal correspondence, project notes, business records, photographs, and legal paperwork. To his credit, Mr. Cooper saved everything. It was my job to decide what was worthy of being preserved. It took three days in the warehouse, but in the end, I shipped off 18 boxes of videotapes and 21 boxes of magazines and books to the scanning centers. I sent another two big boxes of CD-ROMs and DVDs and various other media to myself at DLARC World Headquarters to dig through later.
As that material gets digitized, the Bob Cooper collection in DLARC is growing. It’s early, but you can already find there the complete run of Coop's Satellite Digest, Cooper’s magazine covering the birth of the home satellite industry. It was published from October 1979 through April 1987. And, a complete run of SatFacts, his publication covering the world of satellite television in the Pacific and Asia, published from September 1994 through August 2004. And, the complete run of Community Antenna Television Journal, which was published from 1974 through 1979. AND the entire run of Cooper James Report, also known as CSD2, a short-lived publication directed at TVRO manufacturers and distributors. It was published from August 1983 through September 1985, concurrent with the publication of Coop's Satellite Digest.
That’s the tip of the iceberg: Cooper had many more publications and projects. There will be a whole lot more in the coming months as we continue to process and digitize what I found in Denver.
I talk even more about both of these away missions on the Store & Forward podcast, my new podcast with Zero Retries editor Steve Stroh. You can hear the audio versions in your favorite podcast app, or watch the video version, hosted at DLARC, naturally.
…
Digital Library of Amateur Radio & Communications is funded by a grant from Amateur Radio Digital Communications (ARDC) to create a free digital library for the radio community, researchers, educators, and students. If you have questions about the project or material to contribute, contact me at kay@archive.org.
DLARC want list: https://archive.org/details/dlarc-wantlist
By Steve Stroh N8GNJ
Short mentions of Zero Retries Interesting items.
ARRL Urges Protecting the Amateur Radio 902-928 MHz Band
The Federal Communications Commission (FCC) accepted for public comment a Petition for Rulemaking filed by NextNav Inc., a licensee in the 900-MHz Location and Monitoring Service (LMS), to completely reconfigure the 902-928 MHz band and replace the LMS with high-powered 5G cellular and related location services.
…
ARRL is preparing comments urging protection of existing and future amateur uses in this band. ARRL urges all amateurs to study the proposal and file their own comments describing their activities in this band and the expected effect of the proposed changes. The filing deadline is September 5, 2024. Replies to comments are due by September 20, 2024. Click here for a guide to filing comments.
Meshtastic's Opposition to Proposed Changes on 900 MHz Band
The Federal Communications Commission (FCC) is currently considering a proposal from NextNav that could drastically reshape the 900 MHz band. While this proposal may seem like just another routine reconfiguration, it has significant implications for a broad range of users, particularly those who rely on unlicensed spectrum for innovative, community-driven projects. At the heart of the debate lies the potential impact on open-source initiatives like Meshtastic, an open-source, decentralized communication platform that operates in the 900 MHz ISM band.
As a community, we are raising our voices in opposition to this proposal, and here’s why we believe it’s crucial for all stakeholders, especially amateur radio operators, tech enthusiasts, and public safety advocates, to understand the ramifications of this change.
Understanding the 900 MHz Band and Its Importance
The 900 MHz band is a critical piece of spectrum used for various applications, including industrial, scientific, and medical (ISM) purposes, as well as amateur radio. It’s a unique band that supports a wide array of technologies, from garage door openers and baby monitors to more advanced uses like Meshtastic’s decentralized communication networks.
Meshtastic leverages LoRa (Long Range) technology to facilitate long-distance communication without relying on centralized infrastructure. This capability is especially valuable in remote areas where traditional communication networks are either unavailable or unreliable. The proposal by NextNav threatens to disrupt this delicate balance by reallocating portions of the 900 MHz band, which could severely impact these unlicensed applications.
…
These two organizations representing non-commercial user communities are only the leading edge of what will likely be a tsunami of opposition to NextNav’s petition at the FCC, and the FCC’s Request for Comments - Docket 24-240. There are entire industries that have been built on using 902-928 MHz without the requirement of a license, and they’re “getting along” with the many competing users in 902-928 MHz… unlike NextNav. One prominent company that will almost certainly file comments is Amazon, which builds a neighborhood area network into their home devices, operating on 902-928 MHz (in the USA) called Amazon Sidewalk.
One primary argument I will be making is that NextNav knew the mixed environment and unusual rules when they bought their licenses in 902-928 MHz… and now want to change those rules.
There are already 150+ comments on Docket 24-240. There will be hundreds more, perhaps thousands in the next few weeks. But there’s a tight deadline:
Comment Period End Date: Sep 05, 2024
Reply to Comment Period End Date: Sep 20, 2024
I have started a small, private email list for those who are involved in Amateur Radio (including manufacturers, etc.) or closely related such as Meshtastic so that we can “cross fertilize” our comments to make the strongest case possible in opposition to NextNav with the FCC. Email me if you’d like to participate on that email list.
This great article - The M17 Project by Ira Brodsky KC9TC, mentioned in Zero Retries 0164 last week, is now available online via Digital Library of Amateur Radio & Communications (DLARC), and will be (hopefully soon - technical difficulties) on the M17 Project website.
This article originally appeared in the May, 2024 issue of RSGB RadCom Magazine. This article is Copyright © 2024 by RSGB and is reproduced with kind permission of the RSGB. If you’d like to get this issue of RadCom, or any other RSGB merchandise, the RSGB Shop is at https://www.rsgbshop.org/index.html.
My thanks to Ira Brodsky KC9TC for 1) writing such a great article that explains M17 so well, and 2) working things out with RSGB on behalf of the M17 community for RSGB to allow this article to be made publicly available.
Bryan Hoyer K7UDR of NW Digital Radio on the main@nw-digital-radio.groups.io email list:
Hi All,
DRAWS™ Goes on Backorder Discount Next Week, delivery Mid-September.
This will be the last run of 140 Units as we are moving to a new GPS Receiver.
We will be doing an update to the board and have created a new subgroup, Evolution, to discuss feature requests and new product ideas. Please join and share your input!
I’m a fan of NW Digital Radio not just because they’re a manufacturer of Zero Retries Interesting products from this region (Friday Harbor, Washington, USA), but because I know all of the principals including Silent Keyboard John Hays K7VE.
As a small electronics manufacturer, NW Digital Radio got hammered in the great components shortage of a few years ago, and I’m glad to see that they’re back to the point of resuming production. DRAWS is a cool data modem designed for use with Raspberry Pi computers, and includes support for two radios via standard 6-pin MiniDIN connectors, a 12V input which powered the modem and computer (with ample power margin), some analog IO channels, and an onboard GPS receiver with battery backup (for faster acquisition of GPS data compared to a cold start). NW Digital Radio was careful to design in full compatibility with higher speed modes like 9600 bps (and faster) when using Frequency Shift Keying (FSK) modulation.
But the best part of DRAWS… is the very cool case that NW Digital Radio had custom made for DRAWS:
There’s definitely going to be a “to do list” for DRAWS 2 (?); for example, the RPi 4 and RPi 5 have emerged while DRAWS was out of production, and those have some quirks not present with the Raspberry Pi 3 (which will remain in production for the foreseeable future).
The new Evolution group for NW Digital Radio is at https://nw-digital-radio.groups.io/g/Evolution.
I think I scored the coveted “first post” on the Evolution list! (Gosh I’m such a geek at times.)
Founding Member Annual Subscriber William Arcand W1WRA via email:
[I have been] playing with M17 very early on using various methods you recently outlined. Of course today I use my CS7000 M17 mostly, with a stm32-dvm connected to a FTM-6000’ 9600 baud data port. Setting deviation, etc is quicker and easier than some mmdvm modems in my opinion. I am not about to get rid of my mmvdm setups, but that stm32-dvm board is rock solid, and is now my “reference” setup.
I confirmed that the unit W1WRA mentions is manufactured by Repeater Builder - RB_STM32_DVM. That’s a great recommendation (especially since I also have a Yaesu FTM-6000R) as a foundation for one’s experiments with various M17 units. It’s so cool to keep hearing these reports about the Connect Systems CS7000 M17 portable radio that includes M17 out of the box (with the occasional firmware update).
Despite no mention of M17 on the RB_STM32_DVM product page, I’ll reprint this from the m17-users email list:
I just clarified in an email with Scott Zimmerman N3XCC of Repeater Builder, that their version of MMDVM, which they call RB_STM32_DVM V4 (latest) - https://www.repeater-builder.com/products/stm32-dvm.html does support all the same modes as the current MMDVM firmware:
D-Star
DMR
System Fusion
P25
NXDN
M17
POCSAG
AX.25
FM
IE, it’s just another MMDVM device.
The current verbiage on that web page omits
M17
POCSAG
AX.25
But those modes are supported by the V4 hardware, assuming the version of firmware loaded onto the unit is the latest.
Thus, there is “repeater grade” hardware, and more importantly documentation and support, available to add MMDVM support to many / most Amateur Radio FM repeater systems.
This is really good news for breathing life into tired old, increasingly unused Amateur Radio FM repeaters.
Peter Bloom on the ARDC Community email list:
Greetings from Rhizomatica.
With support from ARDC, we have been working on a software-defined modem called Mercury for quite a while and are excited to share two videos of it in action. Much more info to come, including tutorials.
Feel free to contact us with any comments or questions!
On the email list, I asked:
Could you outline the advantages of Mercury that you’ve been able to achieve to date that are better than competing HF modems?
There was quite a detailed, technical response to my question, and I’ll just provide some limited excerpts here. See the link for full details.
Here is Rafael, PU2UIT, working in the project. Right now we are demonstrating the physical layer, so you read and write from/to the modem just the raw frames (ready to be used, already error-corrected). Here are the frame sizes for each mode (frame size in "full" octets, in bits and the remaining data not byte aligned):
CONFIG_0 (84.841629 bps), frame_size: 12 Bytes / 100 bits / 4
non-byte-aligned bits…
CONFIG_16 (5735.294118 bps), frame_size: 162 Bytes / 1300 bits / 4
non-byte-aligned bits
The following setup for each mode (
https://github.com/Rhizomatica/mercury/blob/eaff517be7ccbad07084e6ee8d6847d2ebda7a33/source/physical_layer/telecom_system.cc#L1347
):
CONFIG_0:
modulation BPSK
ldpc_rate 1/16…
CONFIG_16:
modulation 32QAM
ldpc_rate 14/16
Our primary target is the sBitx, which is the radio we use in our deployments, but I'm carrying now tests with an ICOM IC-7100 to make sure everything is working with a more standard radio.
So far we're not comparing with other HF modems yet, as our ARQ code is not yet production, but already integrated with TNC commands mostly VARA compatible, just set the ports to 7002 (control port) and 7003 (data port). Indeed, I tested some VARA HF ARQ software we have (namely
https://github.com/Rhizomatica/hermes-net/tree/main/uucpd and
https://github.com/Rhizomatica/mercury-connector )
with Mercury and they worked (but expect some bugs in ARQ system at this point).
We aim to be able use free software in the HF solution we provide in our project. Right now we use VARA in our deployments. Our aim is that Mercury will be able to substitute VARA in our deployments. In replacement at first, then keep evolving. For example, right now we are testing Mercury in pre-production mode to be used for data broadcast in
carousel mode (using RaptorQ, code here:
https://github.com/Rhizomatica/hermes-broadcast
for emergency alerts and other small (or not so small) message broadcast. We'll deploy this version in Bangladesh, at fishing boats / for fishermen at Kuakata region at the Bengali bay.
A follow-on comment by Dan Cross:
This brings joy to my heart! I love to see UUCP used over HF.
Oh… I so agree with Cross about seeing UUCP used for Amateur Radio!
There’s additional interesting technical detail in the thread - I recommend reading the entire thing (not to mention subscribing to the ARDC Community email list).
It’s not only cool that they've been so hard at work on Mercury, but that their target for using it is the sBitx radio. A capable open source modem and data communications system running on an open source radio! Kudos to Rhizomatica for this work, and kudos to ARDC for funding this work by Rhizomatica!
If you’re not yet licensed as an Amateur Radio Operator, and would like to join the fun by literally having a license to experiment with radio technology, check out
Join the Fun on Amateur Radio for some pointers.
Zero Retries Frequently Asked Questions (FAQs) — In development 2023-02.
In its mission to highlight technological innovation in Amateur Radio, promote Amateur Radio to techies as a literal license to experiment with radio technology, and make Amateur Radio more relevant to society in the 2020s and beyond, Zero Retries is published via email and web, and is available to everyone at no cost. Zero Retries is proud not to participate in the Amateur Radio Publishing Industrial Complex, which hides Amateur Radio content behind paywalls.
My ongoing Thanks to:
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These blogs and newsletters regularly feature Zero Retries Interesting content:
Dan Romanchik KB6NU mentions “Zero Retries Interesting” topics so regularly on his blog (that I otherwise wouldn’t know about) that I’ve bestowed on him the honorific of Pseudostaffer.
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Amateur Radio Weekly by Cale Mooth K4HCK is a weekly anthology of links to interesting Amateur Radio stories that often feature “Zero Retires Interesting” topics.
Experimental Radio News by Bennet Z. Kobb AK4AV discusses (in detail) Experimental (Part 5) licenses issued by the US FCC. It’s a must-read-now for me!
RTL-SDR Blog - Excellent coverage of Software Defined Radio units.
TAPR Packet Status Register has been published continuously since 1982.
Hot Iron - The Journal of the Constructor’s Club is a delightful quarterly newsletter.
Other Substack Amateur Radio newsletters recommended by Zero Retries.
These YouTube channels regularly feature Zero Retries Interesting content:
HB9BLA Wireless by Andreas Spiess HB9BLA
KM6LYW Radio by Craig Lamparter KM6LYW (home of the DigiPi project)
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Tech Minds by Matthew Miller M0DQW
These podcasts regularly feature Zero Retries Interesting content:
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Foundations of Amateur Radio by Onno Benschop VK6FLAB
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More bits from Steve Stroh N8GNJ:
Store and Forward Podcast - a podcast about the past and future of amateur radio, by Kay Savetz K6KJN (curator of the Digital Library of Amateur Radio and Communications) and Steve Stroh N8GNJ (Editor of the Zero Retries newsletter.)
SuperPacket blog — Discussing new generations of Amateur Radio Data Communications - beyond Packet Radio (a precursor to Zero Retries)
N8GNJ blog — Amateur Radio Station N8GNJ and the mad science experiments at N8GNJ Labs in Bellingham, Washington, USA
Thanks for reading!
Steve Stroh N8GNJ / WRPS598 (He / Him / His)
These bits were handcrafted (by a mere human, not an Artificial Intelligence bot) in beautiful Bellingham (The City of Subdued Excitement), Washington, USA, and linked to the Internet via Starlink Satellite Internet Access.
2024-08-16
Blanket permission is granted for TAPR to use any Steve Stroh content in Zero Retries for the TAPR Packet Status Register (PSR) newsletter (I owe them from way back).
Blanket permission is granted for Amateur Radio use of any Steve Stroh content in Zero Retries for Amateur Radio newsletters and distribution via Amateur Radio such as (but not limited to) Packet Radio Networks, Packet Radio Bulletin Board Systems, Repeater Nets, etc.
In such usage, please provide appropriate authorship credit for the content.
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All excerpts from other authors or organizations, including images, are intended to be fair use. Unless otherwise noted in the article, there are no paid promotional items in any Zero Retries articles.
Portions Copyright © 2021, 2022, 2023, and 2024 by Steven K. Stroh.
Sad to say, I’ve been too absorbed in Zero Retries and related projects like the recent attempt at hostile takeover of a majority of the US 902-928 MHz band to contribute my favorite examples of open source projects to the Open Source In Amateur Radio Wiki. But doing so is definitely “on the list”.
When I first wrote this, it was a gratuitous plug for my favorite 8-bit processor, the Motorola 6809 which was used in the Tandy / Radio Shack Color Computer series. But something nagged at me and I finally remembered that the 6809 was also used in the TAPR TNC-1, which, unfortunately, there is no good capsule description online to link to.
As an indication of how absurd things have become in “mainstream” Amateur Radio media, one primary Amateur Radio publication prefers to reprint tens of pages of archival material every month instead of promoting technological innovation in Amateur Radio. And, they hide what content they do publish behind a paywall, where only a small minority of Amateur Radio Operators worldwide will ever see that content.
For perspective, my watch isn’t the most advanced version (I’m… checking… six generations behind the current model), and it also doesn’t have the optional cellular modem (AKA, the “Dick Tracy” option). Yet my watch… does video. Mind. Blown.
If I tried to describe this to my daughter, she’d probably say “Oh. Tuesday.” This stuff is “native” for her generation.
With sunspot numbers and solar flux at times both above 300, recent daily space weather has been exciting for radio amateurs who watch the sun. We like higher activity because it correlates with a dense ionosphere, bringing with it better conditions on higher frequencies.
This extreme activity also comes with greater geomagnetic disturbance, which cause higher absorption of HF signals.
For exa...
There are many forms of human interface device beyond the ubiquitous keyboard and mouse, but...On a Friday afternoon in July I activated the Charles River State Reserve. This park stretches for 20 miles along the Charles River waterway from Boston upriver to Newton. There are several spots I could have activated but I decided to head into Allston near the Harvard Campus with my Elecraft KH1 Transceiver
Above is a view of my chosen spot off of Soldiers Field Road. I sat down in a folding camp chair with my KH1 and spent a pleasant afternoon sending Morse code.
This section of the Charles River has lots of activity. As you can see there were lots of geese and boaters enjoying the space.
The KH1 with the whip served nicely. You can see a map of the contacts I made above.
Read more at RSGB.co.uk
Years ago I kept a blog of my exploits. I hope you can get some ideas here.
See https://sites.google.com/site/sub9khz/vlf-using-earth-mode/g3xbm-earth-mode-blog .
Looking for a versatile transceiver that’s perfect for roving during VHF contests, drive-up SOTA operations, Super High Frequency activity, everyday use in your home station, and a whole lot more? You’ll find all this and loads of fun with the Icom IC-905 VHF/UHF/SHF All Mode Base/Portable Transceiver, says Michael Murphy, KI8R, who covers the features and benefits of this rig in the video below.
***
Check out the above video and find many more details about the IC-905 and accessories at DXEngineering.com.
The post Video Review: Icom IC-905 VHF/UHF/SHF All Mode Base/Portable Transceiver appeared first on OnAllBands.
RSGB Legacy Fund The RSGB Legacy Fund, thanks to the generosity of donors, has resources...The audio podcast for this issue of The Random Wire dropped two days ago and is available on most podcast services and on Substack at:
https://www.randomwire.us/p/random-wire-reflections-for-issue-b37
Also, please note that links below ending with an asterisk are affiliate links. Purchasing through those links doesn’t cost you more and I get a tiny amount to help offset some of my costs in crafting The Random Wire newsletter and podcast for you. I appreciate your support.
.-. .- -. -.. --- -- / .-- .. .-. . / .-. . ...- .. . .-- / -... -.-- / -.- .--- --... -
.-. .- -. -.. --- -- / .-- .. .-. . / .-. . ...- .. . .-- / -... -.-- / -.- .--- --... -
First, let me describe what I mean by the word restomod? Resto refers to restoration, implying older, vintage equipment. Mod is for modification, but also think “modern.” Restomodding is the process of converting an old piece of equipment so that it has modern capabilities, making it function like something new while retaining the outward appearance of the original.
Wikipedia refers to restomod in the context of automobile restoration:
Restomod: Classic cars that combine original exterior styling with modern applied technologies (such as new suspension, wheels, transmission) or modern interior features (multimedia, etc.) for comfortable everyday use.
For this amateur radio project, I am restomodding a Kenwood PC-1A Phone Patch Controller case to function as a modern AllStarLink radio-less audio interface.
There are some new parts added to the list previously described in Random Wire Review issue 102. Listed below are the parts and supplies for this build...so far! (If there is an asterisk beside a link, that means it is an affiliate link.)
MAX9814 Electret Microphone Auto Gain Control Amplifier Sensor Module AGC Amplifier Board VGA Low Noise* (3 for $9.57)
PAM8406 5W+5W Mini Amplifier Board Class D 2.0 Dual Channel DC 5V Digital Stereo Power Amp Module for DIY Sound System* (2 for $12.59)
5K Ohm,Volume Control Potentiometer, 6 Pins Split Shaft Rotary Linear Dual Taper Audio B Type Potentiometer with Knob* (5 for $9.99)
LM386 Mono Audio Amplifier Module 5V-12V Adjustable* (5 for $7.49)
0.1uF－2200uF Electrolytic Capacitors* (304 pieces for $9.90)
So far, I’ve removed the following items from the PC-1A case: the original board from the PC-1A, a front panel switch, a real panel plate, and the power cord. Still left mounted are: the 8-pin microphone connector, a VU meter, two potentiometers on the front panel, a sliding switch on the back panel, and another potentiometer on the back panel.
I did find a few of these items in my parts bins. The LOSC-brand PAM8406 board is one I picked up a few years ago. And it turns out I have a baggy full of XL6009 buck boosters.
The PAM8406 board can be configured as a Class D amplifier or a Class AB amp. The defaults on the board are (a) Class D amp, (b) shutdown disable, and (c) mute disable. All those are fine so I won’t have to change the defaults. The marks that look like fingerprints on the bottom of the board? That’s how it came from the overseas vendor!
As I started to fiddle with how the PAM8406 board would fit, I discovered that the board is so long that it interferes with the second potentiometer hole in the front of the case. Instead of using the board I already have, I ordered a couple of these small units: NOYITO PAM8406 Digital Amplifier Board 5W 5W Dual Channel Stereo Audio Module*
These smaller PAM840 amps arrived yesterday. Here are two photos:
I have to confess that the LOSC-brand board looks stouter than the tiny NOYITO board. Maybe it’s the two electrolytic capacitors on the LOSC board that give this impression. Looking at the lack of those caps on the NOYITO board makes me think I might need to consider electrolytic capacitors with the NOYITO board.
This should give me room to use two 5KΩ potentiometers on the front panel. A fallback would be to put one of the potentiometers on the back panel and use that location for adjusting microphone gain, but that is less convenient than having it on the front panel.
I think it makes the most sense to put the potentiometer for the PAM8406 amp in the RX GAIN position. This would control volume to the external speaker. The TX GAIN position would have the other potentiometer to allow microphone gain to be boosted through the MAX9814 board.
At this point, I removed the original pots from the PC-1A front panel to make it easier to see the positions I’m describing: RX for external speaker volume and TX for microphone gain.
The original potentiometer knobs fit the modern pots well enough so I’ll try to use them to help maintain the illusion of an original device. The new 5K pots fit well in these two holes.
I’m out of electrolytic capacitors. I could use one on the 8-pin microphone connector and another on the feed to the VU meter. Capacitors should help smooth out the operation of these devices. I ordered an assortment so I won’t run dry:
I haven’t yet sketched out how to put all the pieces together but I’ve been making audio notes while I drive. Talking about it helps me think through how the components will work together.
I think my halfway decent multimeter is in storage somewhere so I did the unthinkable — I drove to my local Harbor Freight and bought a new multimeter. Why would I do such a thing? Convenience, pure and simple.
The Ames Dm1000 looks durable and comes with a case. For my general use (household and vehicles) it is probably more meter than I need. For amateur radio work, it should be sufficient for most tasks, even if measurements prove to be a bit off.
There’s no telling how accurate, precise, or durable this multimeter is. For tool reviews, I often turn to the ToolGuyd but for the DM1000, that site has little meaningful information. The DM1000 is alleged to be a rebadged Uni-T UT61E, a meter that gets decent reviews.
Could I have done better? Certainly. Was there a convenient place to just pop in and buy a reasonable multimeter? Not really. Harbor Freight met my requirements today.
I’m sure I’ll hear some comments about trusting anything from Harbor Freight. I’ve certainly had that opinion in the past. Today, though, as I examine this device, I feel like the overall quality is a bit better than in years past, at least with some thoughtful examination of the products by the shopper.
Despite that just-stated disclaimer that I feel better about Harbor Freight, I also ordered a less expensive (read that as: cheap) multimeter for overnight delivery. This one may live in the pickup truck: KAIWEETS Digital Multimeter TRMS 6000 Counts Voltmeter Auto-Ranging Fast Accurately Measures Voltage Current Amp Resistance Diodes Continuity Duty-Cycle Capacitance Temperature for Automotive* This particular item is part of a deal that includes a wire stripper. One can never have too many wire strippers!
Unlike the Ames multimeter, the Kaiweets device does not come with a case.
Let’s take a look at the physical characteristics of the two devices: the more expensive Ames DM1000 ($70) and the cheaper Kaiweets HT118A ($40). I’m not equipped to opine on the accuracy, precision, or reliability of the units.
The Kaiweets unit takes two AA batteries, accessible through a panel on the back of the device. A single screw secures the door to the battery compartment. The Ames device is similar except it takes a single 9-volt battery.
The form factor and size are similar for the Kaiweets HT118A and the Ames DM1000 devices. However, the Ames device weighs more than (half again as much?) as the Kaiweets. Frankly, the Ames meter feels solid and the Kaiweets feels cheaper, as in lighter in weight and more “plasticky.”
The wire leads for the probes are not the kind that seem to adhere to each other. Leads that stick together drive me nuts. The insulation on the Ames probe leads feels a little more rubbery and substantial than with the Kaiweets device. Both sets of leads are adequate. Both devices also come with a temperature measuring probe.
The main dial control functions fine on both units, but the dial on the Ames device is simpler and less crowded. To my eyes, the dial on the Ames meter is easier to read.
The displays are quite readable for both devices.
Here the devices have backlighting turned on and both are propped up using the integrated leg stand that pops out from the back of the device.
Both devices claim to be true RMS devices. Both boast max voltages of 1000V CAT III and 600V CAT IV. Both have a max 600mA fuse. Both claim to have 6000 count accuracy.
Interestingly, both devices have a non-contact voltage detection (NCV) feature. The two devices differ in how they display NCV detections. The Kaiweets device is simpler: turn the dial to the “NCV Live” position and hold the sensor at the top of the device near the suspected circuit. In the gallery below, you see that the light switch in the OFF position generated a different response (green indicator on the meter and L on the display) than when the light switch was ON (red indicator and H on the display).
For the Ames device, the NCV procedure was a bit less clear: turn the dial to any position and hold down the NCV button. The meter did not differentiate between the light switch in the OFF position and when it was in the ON position. In both instances, the meter displayed a red indicator light.
The Kaiweets device seems a bit more intuitive in actual use because the dial includes the NCV setting and because it has a small nubbin on the top of the meter to indicate where the sensor is. I think the difference between the green light and the red light on the HT118A NCV detector is this: the green light is indicating a circuit is present and the red light indicates electricity is flowing through the circuit. This is an interpretation on my part as this is not described well in the small manual. (Someone please correct me on this.) For homeowners checking residential circuits, the Kaiweets HT118A meter seems a bit easier to use.
Of the two, the more expensive Ames meter feels heavier and more solid, the main dial is less “clicky,” and the probe leads are slightly more substantial. Still, for a toolbox meter for the household or vehicle, the Kaiweets may represent good value. Just be sure to put it into a case of some kind to protect it and to keep the parts together!
I’ll give the overall nod to the Ames DM1000 multimeter. It feels more substantial overall, the dial feels and sounds not too “clicky,” the leads are more substantial, and it comes with a case. The Ames unit feels like it might survive a drop or two, compared to the Kaiweets device. (No drop tests were performed to examine this conclusion!) I feel like I can trust the Ames DM1000 meter more than the Kaiweets meter.
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I didn’t expect to have three XHDATA radios. I thought I’d just try one (the D-808) but then XHDATA offered the D-608WB and the D-200 for me to review. The D-808 satisfies my desire for airband coverage.
Overall, I’m liking the D-808 and D-608WB radios. While the D-808 is not quite the same as a Tecsun-brand radio, it is comparable and perfectly fine for listening to the bands I want. (My Tecsun radio lives in the camp trailer where we depend on it for information when cell coverage is poor.) The D-808 was well reviewed on SWLing.com.
The D-608WB radio is actually a fine unit. This type of household emergency radio is intended to be kept on hand for weather alerts and receiving information over commercial radio frequencies. As such, the radio needs an alternate means of charging, a flashlight, and reasonable performance on AM and FM bands. NOAA weather alert is a must and shortwave reception is a plus.
The D-608WB checks all these boxes and more. Charge it over a USB-C connection, or with a hand crank on the back, or with the solar panel on top. It uses a standard 18650-size battery so it’s easy to keep a spare on hand. It has the obligatory flashlight but also has a variable output LED light underneath the solar panel, good for area lighting in a tent or for late night reading. By the way, the solar panel tilts to help you capture the most energy from the sun.
You can pick up a D-608WB from Amazon* for not a whole lot of money. This unit feels solid, performs well, and has all the features I want in an emergency radio. I like this little unit more than any other emergency radio I’ve tried. It’s a keeper.
I’m listening to it while I write this. I have a microSD card with dozens of my favorite albums inserted into the radio and it is playing in the background for my wife and me. Unlike many small radios, it has a bass port on the back of the radio body that makes it more pleasant to listen to.
I’m still reviewing the D-220 so more on that to come.
We hams are a funny bunch. When friends call each other on the phone, they don’t lapse into descriptions of their gear: “I’m calling on a Samsung model SM-G781U via my home wifi, using a headset that’s a bit of a homebrew.” People just don’t do that, but we hams do exactly this when we talk to each other on the radio. That, and report on our local weather and compare health issues.
I also note that cell phone manufacturers have done a tremendous job with what I’ll call automatic gain control (AGC). AGC automatically adjusts the strength of an input. On the smartphones I’ve used, one can talk close to a microphone or several inches from it, and on the receiving end, it can be hard to tell if the talker is close to the microphone or not. Not so with our amateur radio gear! Distance from a microphone makes a huge difference in audio quality. I routinely hear stations with audio that is distorted because the person speaking their lips up to the microphone and is speaking loudly.
Checking our own audio using a Parrot ought to be part of our regular radio practice, even if only once a year. I tried a parrot on WIRES-X at 41619 but got no response. I’m looking for other WIRES-X parrots. Suggestions are welcome!
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Will the 0.0.0.0 Day bug affect AllStarLink nodes? This thought surfaced as I was reading a security article titled 0.0.0.0 Day: Exploiting Localhost APIs From the Browser. In the configuration of AllStarLink nodes, sometimes we use 0.0.0.0 as the IP address in a configuration file. For example, my manager.conf file has this set in the [general] setting:
Loginbindaddr = 0.0.0.0Binding the IP to 0.0.0.0 provides no additional security beyond the username and password for the node. I’m not particularly worried about this on my home node because (a) I’m operating inside my local network and (b) I use a VPN to reach the node from outside the network. Setting the bind address to 0.0.0.0 is a convenience for me.
Is there risk in doing this? I suppose there is but I deem it an acceptable risk for my use case.
Recently, an entity I work with was affected by bad actors. In popular parlance, they got hacked and lost a chunk of money.
The attack vector started out as you might expect — someone clicked a link they should not have clicked — but it escalated from there to a much more sophisticated operation. I’m still gathering information on this but wanted to get this warning out to my subscribers: be careful what you click! Bad actors are becoming more surgical in their approach and more convincing in their interactions.
If you have not yet enabled multi-factor authentication (MFA) now is the time. I resisted doing this for quite a long time because having to enter something more than my username and password seemed like too much bother. Considering the potential for harm, though, it really isn’t too much bother. If nothing else, you should have MFA enabled for your email and banking/investing services.
I now use random passwords, MFA, and USB security keys to help protect my assets.
The Behringer mic (C-1 medium diaphragm condenser microphone*) and pre-amp (MIC500USB audiophile vacuum tube preamplifier*) combo I bought from a seller on Amazon came with a power supply that did not work. (That might be why I got it for such a great price!) Fortunately, I already had a suitable power supply for one of my Dell Wyse 3040 thin client units that worked perfectly with the Behringer package.
However, to power up the pre-amp you plug the 2.1mm plug into the receptacle on the back of the pre-amp. Alternatively, you can keep that plugged in and plug in (and remove) the wall wart from the 120V socket. Neither method is convenient and both introduce wear on these components.
Instead of manually plugging and unplugging things, I bought a package of inexpensive inline switches. I gambled that the 5.5mm x 2.1mm plugs on the switch would work with the Behringer unit, and it works great.
This lets me keep the Behringer pre-amp plugged in at all times. When I need to use it, I power it up. When I don’t need it, I power it off. I don’t know if this introduces noise into the audio circuit but so far, it’s been fine. The podcast for this issue was recorded with the Behringer mic and pre-amp package using this little switch. This is my kind of solution: simple and effective!
Here’s another plus: this switch (there were four in the package) fits some of my Dell Wyse 3040 thin client devices, too.
On Tuesday, I received a replacement WisMesh Pocket device from Rokland Tech. I reported on the original unit in issue 100.The one point in common with the two RAK-based Meshtastic devices that have failed is my USB-C charger. For the new WisMesh Pocket device, I’m charging on a very low-powered charger. We’ll see if that makes a difference.
Kudos to Rokland Tech for their help. The replacement device worked right out of the box. It shows up on the MeshMap.
Buying something off eBay is always a bit of a crap shoot. I rolled the dice and purchased a well-used Ten-Tec Scout 555 transceiver. (I do like a simple radio!) In the photos, the case looks a bit rugged in spots but the front panel, display, knobs, and rear panel look reasonably pristine. I have another old Scout 555 (reported in issue 96) that may not be working quite right so what is in a side-by-side comparison. If there is actually a distinct difference between the transceivers, I might do a bit of mix-and-matching to make one good working machine.
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