11 June 2021

Told Ya' So

A week ago I published a post titled The IC-705 Reassessed, where I pulled back my previous endorsement of the IC-705 due to the often crippling RFI issues. I linked my post to the most active IC-705 Facebook page and, as anyone with experience with Facebook can guess, the flamers and the tolls crept out of the shadows and accused me of everything from exhibiting signs of advanced dementia to criminal-level stupidity when it comes to my ability to investigate and mitigate RFI.

I knew it would happen, and I enjoyed the repartee. 

But I also thought I'd give Icom a chance to respond to the issue, so I sent them a tech support request through their website:

"Dear Icom, I have a problem with RFI over what I suspect is the USB connection that is nearly impossible to mitigate. The issue exists for both the battery charging over USB connection and USB rig control. I've tested with a variety of USB cables, all heavily 'choked' using ferrite cores, and tested with a small group of Windows 10 laptops and tablets. The RFI, particularly on digital modes, overwhelms the rig. The problem exists on 20, 40 & 80 meters, but seems worse on the lower bands. Has Icom worked out any mitigation strategies for this issue?"

Here's the response I got from Icom USA:


Well gee, even Icom admits there's an issue...

I have a lot of confidence that Icom will get this fixed. The IC-705 is a flagship product in Icom's Amateur Radio lineup, and the rig has the potential for a very long (and very profitable) production run, so Icom knows they have to get this right. I think my biggest fear is that the RFI issue isn't one that can be addressed in firmware, and IC-705 owners will have to send their rigs back to Icom for board-level work.

I intend to 'poke' Icom USA on this at regular intervals, so stay tuned.

W8BYH out

05 June 2021

The IC-705 Reassessed

Two months ago I wrote an initial review of the IC-705, giving it all-around high praise.

Today I have to pull back on that somewhat slobbering fanboy of a review, and remove the IC-705 from my 'recommended' list. The radio has a major, and crippling, RFI issue if you want to run it on digital modes over USB under field conditions.

Simply put, the induced or coupled RF noise picked up by the USB cable floods the rig with RFI. We are talking noise and hash from one end of the band to the other, and the noise gets worse if the software you are running, like Winlink, initiates a command dialog with the radio (in Winlink, that's referred to as 'starting a session'). And it's a complex issue. It's not simply USB line coupling, or laptop interference, or antenna location. It seems to be a sensitive interplay of all three. You can never really be sure what the real root of the problem is. The one key factor, however (based on my testing) seems to be antenna location. The further away your antenna, the less of a problem you will have.

I didn't notice this issue when I did my first post back in March because I hadn't run the IC-705 in a portable (field) environment. All my testing was done in my shack, where my antenna is 75 feet away on the other side of my house. Operating this way, the radio is a champ on digital modes, and that's how I wrote it up in my March review. But a week later I set the radio up at a local park using my Chameleon vertical antenna and the same laptop I use in my shack, and that's when I discovered to noise. I've since had the rig in the field twice more, testing with various antenna setups - a mag loop and an EFLW - and the problem is always present.

Here's a video I made while using the IC-705 and my Chameleon mag loop antenna a few weeks ago during a POTA activation:



Now, this RFI problem is not unique to me, or to my radio. I have three friends in my local Amateur Radio club who own IC-705's and they report the same issue. If you go to the IC-705 Facebook page or the IC-705 Groups.io email reflector you'll find plenty of discussions on this issue. Of course the fanboys will crawl out of the woodwork and tell you you're not keeping enough cable separation, or you are using the wrong type of USB cable, or you've got a 'noisy' laptop, or you are not using enough chokes, or the solar flux-to-ground coupling ratio is too low, or some such bullshit. I have tried every reasonable fix for this issue. I've tested against multiple laptops and Windows 10 tablets, I've tried a wide variety of heavily choked USB cables. I have enough common mode chokes attached to the feedlines to soak up a nuclear-level EMP. Nothing fixes the problem entirely - the 'hash' is always there at some level.

As I mentioned above, the one big delta - the variable that seems to provide the best mitigation - is antenna location. All things being equal - the same radio, laptop, USB cable, feedline chokes and antenna design (EFLW) - at home I get virtually no noise or hash when running digital modes, in the field the radio is overwhelmed by RFI.

The IC-705 was specifically designed for portable field use, and that's how Icom markets it. The owner has a right to expect that the radio will work in the field, on all modes, with a less-than-ideal antenna and cabling setup. The expectation shouldn't be that the owner has to schlepp around 75' of coax and enough iron ferrite (in the form of chokes) to sink sink a small boat, just to send a Winlink message. 

So let me recap where I'm at with the IC-705:

  • On voice modes, whether in your shack or portable, this is a superb little rig. It is every bit as good as its fanboys claim it is
  • On digital modes, in the right environments, the IC-705 is a digital mode beast. I have run my rig, in my shack, on JS8CALL for eight hours continuously and it never broke a sweat
  • Portable on digital modes, however, it's a mess, particularly with Winlink and JS8CALL. The RFI issue makes it all but unusable and it's virtually impossible to fully mitigate the interference

Because of this last bullet point, I no longer recommend the IC-705.

This RFI issue is Icom's to address and fix. Frankly, I'm surprised this issue wasn't caught by Icom in testing, and I'm disappointed that the ARRL test lab didn't catch is in its otherwise outstanding review of the radio.

There's more to come on this RFI problem. Right now I'm focusing on the radio's wi-fi connectivity feature as a solution, but I'm still testing and evaluating. So stay tuned for an update on the 705 saga!

W8BYH out

01 June 2021

It's June 1st - You Know What That Means!

 


I get almost as excited about the opening of hurricane season as I do about Christmas. For those of us who live 'on the corner' (on the corner of the southeast US) - Florida & Georgia - we are prone to get hammered by both Atlantic basin storms, and Gulf of Mexico storms. It's inevitable. Set your watch by it. Then toss in the southeastern 'tornado alley' that stretches across northern & central Georgia, and this state gets some complex and dangerous weather from March through September. 

So 'Jawjah', get your emergency radios and flashlights ready, go buy a couple dozen spare batteries, keep your phones charged, your gas tanks full, and keep your weather eye on the horizon.

Because it's coming. Maybe not this year, or next, but it's coming.




And on that cheerful note...

W8BYH out

12 May 2021

Position, Navigation, Timing

The on-line magazine GPS World posted an article today that brought out the geek in me. The article titled GAO Report: 'Use resiliant tech vs. GPS as DOD primary PNT' discusses vulnerabilities in our GPS system and encourages development of autonomous solutions that are less vulnerable to jamming or unintentional interference.


Here's the bottom line: our GPS signals, in fact all satellite navigation (GNSS) signals - the US GPS (Navstar), the EU's Galileo, the Russian GLONASS, the Chinese Beidou, and others like India's regional NavIC network - are relatively easy to jam. In fact, hostile actors like North Korea and Russia do it all the time. Yet dependency on GPS-based positioning, navigation and timing continues to grow within the DoD (and more exponentially, in the civilian world). And as dependency grows, vulnerabilities grow.

What does this mean for Amateur Radio? More and more radios are being designed with built-in GPS receivers. They've been in HTs for well over a decade (every DSTAR and C4FM HT, and most mobiles, now have integrated GPS). The GPS signals are used mainly to determine location - figuring out where you are so the radio can find nearby digital repeaters. But more and more HF radios are being built with integrated GPS receivers. There's a few reasons for this. For example, Icom's new IC-705 has a built-in GPS receiver that is there mainly to locate the radio for DSTAR functionality. But the GPS receiver signal can be out-boarded to a computer to support location based apps and synchronize the computer's clock with GPS time.

This functionality will become increasingly important as the ham radio community moves more and more to 'time sliced' digital modes like FT8 and Automatic Link Establishment (ALE). There is even talk about expanded use of frequency hopping, which is legal in the Amateur Radio Service as long as a public frequency hopping key is used. Frequency hopping is absolutely dependent on precise timing, and all radios in the frequency hopping network must use the same time base. The best source for that common time base is GPS.

[Geek segway here. So, how come GPS time is so accurate? Each US GPS satellite carries two atomic clocks, and those clocks are constantly monitored and adjusted by the GPS ground control stations. An extremely accurate time signal is continuously broadcast by every satellite, as part of the navigation signal. A GPS receiver can strip out that time signal and make it available for use by other applications. This is why there's a GPS receiver on every cell phone tower in the US. The tower doesn't care about the location signal - it knows were it is. What the receiver does is provide the very precise time signal needed to coordinate cell zone hand-over.]

What impact could GPS jamming have on Amateur Radio? Honestly, not much in the near term. We're still not dependent on extremely accurate time signals. The dependency is coming, but it's not here yet and likely won't be for years. Additionally, the risk of a hostile actor like the Chinese or North Koreans jamming GPS signals over the continental US is unlikely; such an act would be interpreted as an act of war, and as goofy as some of our enemies are I doubt any of them would be dumb enough (or are capable enough) to try something like this.

But large-scale Amateur Radio dependency on precise time coordination is coming, so we'll keep an eye on this. After all, it's not like I've got anything better to do with my time.

W8BYH out

08 May 2021

The Worst Book You Need To Read

This is very much an 'anti-woke' post, so if you are offended by concepts like personal responsibility, the death penalty, useless degrees and ugly truths, then do us both a favor and move on...

________________________________________________________________________________


Still here? OK, let's get going.

A friend of mine, fellow ham, and something of a medical expert (a real one, not a self-appointed one) has been recommending the book One Second After for over a year now. So recently I had some holes in my Kindle reading list and decided it was time to give this a read.

I'm of two minds on this novel. On one hand, it covers a lot of critical topics related to a total collapse of society due to something like an electromagnetic pulse (EPM). On the other hand, it's poorly written and can be a tough slog (more on this at the end). 


The author, William Forstchen, clearly has a strong grasp of the issues related to an EMP event. Forstchen uses the (somewhat likely) nuclear weapon scenario - North Koreans and mad mullahs cooperating to pop air-burst nukes across the US. The same thing can happen if the Sun belches out a Carrington Event-level coronal mass ejection (CME) (less likely in the short term, but inevitable in the long term). One of the things I like is that Forstchen almost completely avoids the silly survivalist fanboy stuff - which rifle or caliber is best, which knife blade shape or handle material is best, which lean-to shelter design is best, etc. Instead, he focuses on the immediate and long term impacts on society. When national, state and even county-level government is incapacitated or wiped out, how do small isolated cities and municipalities manage issues like establishing a functioning government, selecting leaders, prioritizing resources, providing services, enforcing laws and establishing a common defense. 

The decisions quickly become pretty basic, and brutal. How do you manage a shrinking supply of food and medicine? How do you ration medical care? What do you do with hardened criminals when they can neither be jailed, banished, or effectively rehabilitated? Do you establish and carry out a death penalty for crimes that used to just get people locked up, but now are a direct threat to the survival of a small society (stealing food or medical supplies, sabotaging key infrastructure like water purification systems, etc.). In this situation, morality gets re-defined, and communities will be grasping for ideas and rules around which they can build a functioning moral and legal center. When the nukes go off, all fluff and pretense is stripped away. No 'wokeness', no ambulance chasing lawyers threatening to sue, no freeloading. You step up and contribute in real ways, or you die.

The book is a novel, and Forstchen sets the story in a semi-rural town in North Carolina. The town is small and isolated enough that everybody knows everybody, but not so isolated that outside influences don't come into play. This sets up a very plausible scenario of a small town forced to fend for itself with only the resources it has on hand, and ultimately having to make hard choices about how to deal with external threats, from relatively innocent refugees just looking for food and water, to roving bands of criminals intent on raping and pillaging as they move from town-to-town.

Let me put this out there for the Amateur Radio audience - there's virtually no discussion in this book of ham radio beyond a passing reference about checking to see if some unnamed ham radio operators still have working equipment. Like I said, this book focuses mainly on the larger societal impacts of an EMP event, not the nuts and bolts of survival. Does Amateur Radio have a role in this scenario? Yes, but only if modern, sensitive radio gear survives. This implies foreknowledge of the attack or event, and the ability to shield equipment from the EMP pulse. We'll likely have a day or two of warning if it's a CME. An attack by hostile actors will come with no advanced notice. Your spiffy new SDR radio is just as EMP-proof as your iPhone, which means it'll be toast.

As I mentioned above, the author clearly has a firm grasp on the overall impacts of an EMP event (he's even testified before Congress on the subject). A post-EMP world will be a grim place. There will be no electric power - the power grid will be fried. Literally fried. Everything electronic will be gone - either destroyed in the initial high energy pulse, or incapacitated by the lack of electricity. That's not just your laptop and smartphone. Your cars won't start. You won't be able to get to your bank accounts. All of your electronic appliances will be destroyed, and this includes any medical devices you depend on. The electronic controls that manage things like the water purification systems in your municipal water supply won't work. There'll be no 911 dispatch. No police response. No fire response. No EMS response. Fresh, refrigerated and frozen food will spoil within days. There'll be no lights. When the sun goes down, darkness will overtake everything, and predators - human and animal - will rule the night.

From a human behavior perspective, it'll be a world turned upside down. The best and worst in people will quickly emerge. This is when the true leaders will rise to the surface - people who know how to motivate others, manage resources, set goals, organize effort, set the example, and make the right decisions regardless of how tough they are. These will be mostly ex-military (mainly officers and non-commissioned officers), law enforcement and emergency services personnel. It's also when we'll see the value of the people who keep our infrastructure up and operating - electricians, carpenters, mechanics, plumbers. Medical personnel, particularly doctors, nurses and PAs with strong backgrounds in emergency medicine, general medicine and public health will be worth their weight in gold. Sadly, they'll be working with quickly dwindling stocks of medicines and other supplies, and they'll soon be battling to control basic health issues like water and insect-borne diseases (dysentery, malaria, etc.), infections, malnutrition, and a whole host of 'third world' health problems.

Who else would be considered of value? If you learned a trade or got a degree in something useful like electrical or civil engineering, or served in the military and developed basic leadership and organizational skills, or know how to farm and raise livestock, you have something to contribute and should be OK. But let me be blunt here - if you never developed a work ethic, spent your days playing on-line games, or never thought beyond the next welfare check, you better be willing to learn fast and develop some needed skills, or you will be quickly turned out. And no, cooking meth is not a 'skill', and that women's studies degree you're hoping Bernie Sanders will help you pay off will be as useless as tits on a boar.

I also need to touch on something that Forstchen mostly ignores - the importance of faith, church communities and the clergy. Many people will immediately turn to their local pastors and their church community for guidance and support. In my opinion, clergy (I'm talking mainly about trained and ordained Christian and Jewish clergy here) will be absolutely essential. They will provide the moral guidance and the left and right boundaries needed as leaders struggle with the task of rebuilding a functioning society. In addition, many Protestant denominations like the Mormons, the Salvation Army and the Southern Baptists view disaster relief as an important ministry. They have the organization, training and supplies needed to provide at least short term relief in many communities.  

If you think this is all just academic and nobody really knows what will happen, I've got news for you. This happens in small and limited scale almost every year. Think Hurricanes Katrina and Maria. Immediately after Katrina, people in the rural areas of lower Louisiana and Mississippi who did not evacuate, but had basic skills and emergency supplies, did OK. Not great, but OK. New Orleans, on the other hand, quickly descended into a lawless and chaotic cesspool. I'll leave it up to you to figure out why. The same thing played out in Puerto Rico after Hurricane Maria in 2017. We all heard the tales of woe coming from the major cities on the island, as the elected politicians (another useless skillset) pointed fingers at everyone but themselves. But in the rural areas of the island, in the small towns and villages that were used to frequent power outages and poor communications, the residents essentially did OK. The had the necessary supplies - generators, battery powered radios, flashlights, food, water, etc. They had also developed the mental toughness needed to see them through something like Maria. 

Getting back to the book, while the author has a firm grasp on the aftereffects of an EMP or CME, he's no novelist. The book is readable, but Forstchen has no real experience in writing dialog, his characters are poorly formed, and he suffers from a bout of what I call 'Tom Clancyism'; all the good guys are heroic, all the bad guys are the lowest of the low. All former military are steely-eyed combat veterans who never make bad decisions. All law enforcement are highly competent, all politicians are crudballs (well, at least he got that right). 

But the book is important because it makes you think. I urge you to read it and then spend some time considering your own situation. Do you have the skills, the basic supplies, the mental attitude and toughness it will take to survive the rebuilding of a society that has been set back 150 years?

W8BYH out

28 March 2021

The Computer Museum of America

I'm a computer guy. I've been fascinated by them since I was a little kid back in the 60's (that's the 1960's, for you Millenials who are math challenged). It only makes sense. I grew up in the glorious era of American achievements in science and engineering. We were racing to the Moon. The astronauts and the engineers building the systems that sent the astronauts into space were our heroes. And computers were everywhere. We kids were made to understand that American prowess in raw computing power, along with American drive and excellence in aerospace engineering, were what was pushing us forward in the race to beat the damned Russkies - at anything. 

But in the 1960s a computer would quite literally fill a room. Or two. Computers were fascinating in concept, but unachievable in reality unless you attended a well-heeled school that provided access to a computer (usually via a time sharing system), or were one of the lucky few who's parents or relatives worked in a job that provided access to a computer. My first direct access to a computer didn't come until the mid-1970s when, in college, I had to run some insect-borne disease infection models on the university's IBM mainframe system. You'd go to the computer room window and tell the geeks what simulation you needed to run. They assigned you to a terminal while they pulled the card deck, ran it through the card reader, gave the computer time to compile the program and then sent you a notice through the terminal that the program was ready to run. These terminals were nothing more than a teletype-like keyboard and printer - no CRT interfaces for us low-life undergrads. You knew the program had successfully compiled and was ready to run when the teletype gave you two dings and chugged out a 'READY' line of text on the fanfold paper. But it was glorious! The entire resources of that behemoth behind the window were at your disposal. You could change variables on the fly, run looped simulations to test exponential increases or decreases in vector transmissions, and watched as your test populations of disease victims either survived or died based on various insect control measures. The experience sticks with me today, not because I couldn't kill enough mosquitos and repeatedly wiped out over half the population of some notional West African country, but because those sessions gave me direct access to a computer program that allowed me to control the multiple related variables and provide real-time feedback. I was hooked! 

Unknown to me at the time, there were forces at work in places like Silicon Valley that would upend the computing paradigm and create the concept of the 'personal' computer. When I became aware of this sometime in the late 1970s I became fascinated with the concept but could only participate on the margins - most of these 'personal' computers like the early Apples or CP/M systems cost almost as much as a new car. My first computer was the $99 dollar (that's 1981 dollars) Timex/Sinclair 1000. Oh, and the additional 16k memory module was an additional $99. That's almost $600 in today's inflation adjusted money. But hey, it was real computer! A somewhat crippled computer, yes, but at least it had a real CPU, a video driver, could load and save data and programs on a tape drive, and had built-in BASIC.

Although I was not a computer science major, my professional career with the US Army Corps of Engineers kept me in close contact with computer developments. We transitioned through a wide variety of computers and operating systems as our software applications matured. The list of systems I worked with reads like a pantheon of personal computer and workstation development - Commodore 64 & Amiga, Apple IIe & MacIntosh, DEC VAX (various models), SGI Indigo, HP/UX (various hardware platforms), Wang, Sun Microsystems, GRID and of course the various iterations of IBM PCs and clones - Kay, Compaq, Gateway, Dell, Heath/Zenith, HP, you name it. I have lived the arc of personal computer development, and it's been a fascinating journey.

A year or two ago I became aware of a museum here in the Atlanta area titled the 'Computer Museum of America'. It appears the museum is an extension of the collection of Lonnie Mimms, a commercial real estate developer and avid life-long computer collector. I suspect much of what's in the museum came straight out of Lonnie's garage. So yesterday the XYL and I took a few hours to drive up to Roswell, GA to visit the museum. Suffice to say, I had a great time and was delighted to visit with some 'old friends'.

Long considered the world's first true 'personal' computer, the Altair 8800 was just a box with
blinking lights, but those blinking lights were connected to a real computer
(based on the Intel 8080 CPU chip) and the computer was a huge hit.
Bill Gates and Paul Allen wrote a BASIC programming language for the Altair, the project
which launched Microsoft


The board of myth and legend, and the start of an empire.
An original Apple I board, laid out and likely hand assembled by
Steve Wozniak ('The Great and Powerful Woz', according to Sheldon Cooper). 
These boards were never assembled into complete computers by Apple. The idea
was that the buyer would supply their own case, keyboard and monitor.
Woz was perfectly happy selling the boards this way, but Steve Jobs saw the
commercial potential and pushed the development of what would become
the Apple II. The rest is history. 
There is a direct but tortured line that leads from this board to your iPhone


The Timex Sinclair 1000 - my first computer


A Radio Shack TRS-80 Portable Computer. The first successful portable computer, and one
that was so successful that good used examples are highly sought after today. Built for
Radio Shack by Kyocera. It's still one of my 'Holy Grail' computers


Ah Osborne 1 'portable' computer. This was the first full featured computer specifically
designed to be transported from place-to-place. At 12 lbs it wasn't so much portable as 'luggable'.
It had a tiny 5" screen and two (two!) full-height single sided floppy drives, but came with so much
quality software like Wordstar and SuperCalc that the joke was the buyer was paying for the
software and Osborne threw in the computer for free.
Many say that the Osborne is your laptop's great-grandfather, although I would disagree. My opinion
is that the Radio Shack TRS-80 Portable Computer (seen above) really proofed out the concept of
the 'always ready' battery powered lightweight portable computer


Who remembers Byte magazine?
It was THE premier micro-computer periodical and was extremely influential in the industry.
If Byte gave your hardware or software a good review, you were a success in the industry.
I particularly loved Jerry Pournelle's monthly 'Chaos Manor' columns. Jerry was a noted sci-fi
author who also loved to write about computers.


For every one griping about how hard it is to download and install applications, let me introduce how 
cavemen used to do it. There is not a single computer in this lineup - these are all just
input and output devices that connect to an IBM mainframe computer. It's a line of card punch units,
card readers, card sorters, paper tape readers and line printers.
You could expect to see every one of these behemoths in every computer center before the arrival of tape drives


One of the neat displays is a timeline of information technology development in relation to
other world events and technology developments. One of the interesting things my XYL
noted is the comparison of computing technology with the development of children's toys.
Once the toy manufacturers figured out that computer chips don't HAVE to
be used in computers, and can be re-proposed into electronic toys, the race was on!


And speaking of XYLs, here she is pointing out one of
my heroes in computing history, Rear Admiral Grace Hopper


Anyone need a Cray? The museum has lots of them. In fact, the
museum director told me that they think they have the world's largest collection.
This shot of a Cray1 shows the hand wiring that was used in early units.
Cray hired experienced loom operators from the textile industry to
do this work


Lots and lots of Sun, Cray and Silicon Graphics floor models (ha, ha). I call this 'geek alley'


The museum offers a small, but well done, exhibit on the WWII Enigma
code machine used by the Germans, and ultimately 'cracked' by British and 
American code breakers. By the end of the war the Allies were often reading
Enigma coded traffic before the intended recipients got it


Let me wrap this up by saying that while the museum was a fun experience, there's a lot of room for improvement. Too many of the displays are not well lit. Most of the large floor mounted systems like the Crays and Silicon Graphics units are presented as just dark, shadowy lumps of computer. The designers of these systems were proud of their work and put a lot into the industrial design (particularly the Crays). Hey Computer Museum of America, light 'em up! Next, there's a clear dearth of later, but significant, desktop units like the Sun SPARC workstations and the SGI Indigo series, and some of the HP/UX desktop systems. A display and discussion about the various operating systems would also help a lot with context. The museum also seems to want to go in a few directions with special exhibits, like computers in movies (think 'War Games'), but all we see are a few posters, and some covered displays.

And last, there's a lot of floor space devoted to the US space program up to Apollo. Unfortunately what's on display just doesn't seem to fit the overall theme of the museum. It's as though someone offered them up some space program stuff and the museum said, "Sure, we'll take that!" without any thought about how or where it fits into the overall theme. I'd recommend they just scrap the whole exhibit.

On our way out we had a nice discussion with the museum's director of operations (who was also manning the cash register). She hinted that COVID has really taken some wind out of their sails in terms of visitors and revenue. I don't doubt that. We were two of just four visitors on a Saturday afternoon. Here's hoping that post COVID the museum is able to get back on path and expand and enrich their exhibits.

So, do I recommend you visit the museum? If you live in or are visiting the Atlanta area, sure! Especially if you are a computer geek. There's more than enough on display to help scratch that geek itch.

W8BYH out

23 March 2021

A Digital Dilemma - TNCs But No Radios?

Sometimes stuff just happens. For a few weeks I have been lazily working on a post about the Kenwood TH-D72A, singing its praises and encouraging you to go get one of these classics before Kenwood pulls the plug. Looks like they were a step or two ahead of me, because I saw this posted to the Gigaparts site late yesterday:

Crap.

Some wags on Facebook chided me, telling me Kenwood announced the death of the D72 at the same time they announced the pending demise of their flagship TH-D74 DSTAR/APRS handheld. Honestly, I don't remember seeing anything about the demise of the D72. Maybe I was just focused on the announcement of the D74 and didn't pay attention. Or maybe it's because I'm getting old. Or both.

Anyway, this post will now take a turn to a topic I've been thinking about for a while - the death of the TNC-capable VHF radio, and what to do about it. 

Many say, "packet is dead, nobody needs TNCs anymore", and the manufacturers seem to be leading that chant. Kenwood is (was?) the last manufacturer to support general purpose TNC integration, either by building rigs with built-in full featured AX.25 TNCs, like the TH-D72a and the enormously popular (and still in production, I think) TM-D710a. Kenwood was also the last mainline manufacturer to make a mobile VHF radio with a data port that allows the user to hook up an external TNC. The TM-V71A is still listed as available on Kenwood's website, but is out of stock with all retailers. It too may just be waiting for the undertaker. 

Icom and Yaesu have not offered VHF mobile radios with built-in TNCs for a long while, but until fairly recently they each kept a few radios in their lineup with 6-pin DIN data connection ports for external TNC connections. I don't know when Yaesu last offered a VHF mobile rig with this capability, and Icom's last model, as far as I can tell, was the the ID-880H DSTAR rig that went out of production at least two years ago.

Yaesu has kinda' sorta' redeemed itself by keeping mobile and handheld rigs in its lineup that have built in 'KISS' (keep it simple stupid) TNCs. A KISS TNC offers a partial implementation of the full AX.25 packet protocol, leaving out things like digipeat, mailbox and flow control capability. This means a manufacturer can provide key TNC functionality with much lower hardware overhead. For APRS and Winlink use, it's a great compromise. However, Yaesu seems to have so tightly bound the KISS TNC functionality to APRS in their rigs that it's tough to get the radios to work with Winlink. In fact, I don't know that anyone's been able to do it.

Today if you want to get into packet APRS or Winlink your best bet may be to go buy an HF rig! Yup, both Icom and Yaesu still make all-mode multi-band (HF/VHF/UHF) 'shack-in-a-box' radios that have data ports on the back. The Icom IC-7100, the Yaesu FT-991A and the classic Yaesu FT-818 are still for sale, even during this time of 'the Covid'. The IC-7100 and the FT-991A will both give you up to 50 watts of output on VHF. The FT-818 will only provide a few watts, depending on your power source, but still, it's amazing what that little rig can do.

Rear panel of the Yaesu FT-991A. The data port is highlighted in red


Rear panel of the Icom IC-7100. The data port is highlighted in red


Rear panel of the Yaesu FT-818 QRP rig. The data port is highlighted in red

In fact, this is exactly how I do it. My Winlink 'station' is a Yaesu FT-991A. It handles both HF and VHF Winlink. For the VHF side I'm using a Coastal Chipworks TNC-X connected to the radio's data port. Works like a champ.


So maybe if you want to do VHF packet, Winlink or APRS you need to first go HF!

W8BYH out