Author Archive
George W5JDX Sets Rig on Fire!
January 16th, 2020 | 
Author: Channeling his inner Jerry Lee Lewis, George Thomas W5JDX set his dual-band rig on fire at the Central Mississippi Amateur Radio Association on Tuesday evening. All for demonstrating DIY Projects with Arduino and Raspberry Pi. Not everyone is aware that W5JDX is an accomplished musician. George brought the house down, to say the least, with this Arduino Grand Finale. But let me explain.
The only fire involved was W5JDX using a lighter to dramatically raise the temperature of a heat sensor attached to an Arduino. But, the voice chip in an Arduino “hat” very audibly announced: “Your rig is on fire!“. All done in the fine instructional style that led the Dayton Amateur Radio Association to give him a Special Achievement Award in 2013 for his tutorials on AmateurLogic.TV and the Smoke & Solder segment on Ham Nation.
The presentation was exceptionally well received. We were fortunate to snag George for a talk since he’s very, very busy. Not only with AmateurLogic.TV, the very first video podcast in the world of any genre, but the highly popular Smoke & Solder segment on Ham Nation, but as an RF Engineer for a chain of radio stations in Central Mississippi. This talk was streamed via Facebook Live at the club’s page there. For followers of AmateurLogic.TV, one may recall a mishap that a former podcast member, Jim Burrell (N5SPE), had with a propane torch. Jim has taken much grief over that episode for years. Hmm. I guess that Jim now has good company, with George’s rig “on fire!”
Here’s my produced version of George’s talk, shown below. The brightness of the projection screen’s reflection made my HD camera go darker than I’d have liked. I’ll remember that and move it to the side to avoid that next time. The Facebook Live stream was just to my right and didn’t suffer this situation.
Smoke & Solder Host to Kick-Off Banner Year of CMSARA Speakers
January 11, 2020. (Brandon, MS): For Immediate Release
Information Contact: Frank Howell K4FMH k4fmh@arrl.net
A fan favorite from the internationally known video podcast, Ham Nation, kicks off the 2020 programs for the Central Mississippi Amateur Radio Club. “We are delighted to have George Thomas W5JDX, star of the Solder Smoke segment on Ham Nation and founder of AmateurLogic.tv, give our first presentation on January 14, 2020,” said Frank Howell K4FMH, Vice President for Programming. Ham Nation Founder Bob Heil K9EID says that Smoke & Solder is by far the most popular segment of the show according to email and other feedback. George’s topic will be, “DIY Projects Using Arduino and Raspberry Pi,” beginning at 7:00pm at the Rankin County Extension Service and EOC Building. CMSARA President Quinton Frasier KW5TON added, “I’m excited to see George W5JDX in person this month at our meeting. It’s unusual that we could get him to give a live talk since he’s so busy with Ham Nation, Amateur Logic TV, and his day job of RF Engineer for many radio stations in the Central Mississippi area.”
George W5JDX is only the first well known ham to headline this year’s program agenda, added Frank K4FMH. “We will follow George with the prolific author, broadcaster, and ham radio operator Don Keith N4KC in February.” Don’s recent book, Firing Point, was made into a very popular movie, Hunter Killer, with others on the way. He is a prolific author of books about shortwave and amateur radio, one of which is The Amateur Radio Dictionary: The Most Complete Glossary of Ham Radio Terms Ever Compiled. Don’s February presentation via Skype will be on Ham Radio Lingo. Our year will backend with Rob Sherwood NC0B, producer of the Holy Grail of receiver measurement ratings, the Sherwood Tables. Rob’s talk, also via Skype, is titled, “How to Use My Tables.” These are very well-known amateur radio operators but we have much more during the year planned for presentations.
“We wanted to blend some well-known ham speakers that we do not regularly get to experience in a club setting with informative topics from both our own members and other area hams,” Frank K4FMH said. “I think we’ve done that.” Topics and speakers include operations on six meters (Mike Duke K5XU), WSPR (J.D. Toony K5HH), APRS (Mike McKay APRS), and digital modes on HF (Eddie Pettis N5JGK and Carolyn Irons KJ5RC). We will also cover preparing for contest operations (John Struemph K1JHS), establishing basic test equipment on your workbench (Tom Brown AE5I) and a festival of pictures of CMSARA member shacks during a program called Shack Night!. Frank K4FMH said, “I’m very pleased to have area hams who are affiliated with the Jackson ARC and the Vicksburg ARC to deliver top flight presentations to our membership and meeting attendees.” The ability to have an interchange of ideas and experiences from area hams is a real benefit to maintaining a vibrant club.
CMSARA welcomes non-members, hams who are visiting the area, and groups from nearby cities to join us at the Rankin County Extension Service auditorium where we have plenty of seating, good audio-visual equipment, and Internet access. We keep the “business” end of our club to a minimum and include a half-hour of pre-program fellowship as well as after the program itself. VE Testing is available every month with the exceptions of June and December due to Field Day planning and our Christmas Party respectively. The club has periodically had car pools of hams from as far away as the Starkville and Columbus areas attend CMSARA programs.
J.D. Toony K5HH, Vice President of Special Events added, “This will be an exciting year for radio amateurs in the Central Mississippi area. Not only for this month program agenda but for the multiple outings we are planning, a group Field Day, our new involvement with the Girl Scouts program, and a new repeater Net for new hams.” CMSARA welcomes visitors so get a car pool together and come visit us! Our website at http://centralmsham.club has updated information as well as via our Facebook group (https://www.facebook.com/groups/CMSARA/), e-mail (centralmsara@gmail.com) and telephone (601-345-1654).The Central Mississippi Amateur Radio Association is a non-profit 501(c)(3) status Mississippi corporation serving counties in the Central Mississippi area. We focus on promoting having fun within the hobby and serving our communities through emergency and public service communications. We meet monthly on the second Tuesday at the Rankin County Extension Service / EOC Building, 601 Marquette Road, Brandon, MS 39042. Contact us at 601-345-1654 or at centralmsara@gmail.com for additional information. Any program changes will be communicated via the club website and Facebook page.
Is the ARRL Listening About Shipping? Or is it just me…
A few months ago, I challenged the ARRL’s new mission to serve members in a more effective way by bringing “value” to members. I suggested that one quick “win” would be to stop selling through Amazon (at a 55% discount) and use that money-per-book to fund “free shipping” for members who purchase books. Many readers just didn’t read beyond the title of “free shipping” before raining down the it-will-just-be-passed-along-to-members rhetoric. This does not understand that the League would make a greater profit margin by selling at the 100% retail price (even with whatever discount the member may receive by being a Certified Instructor, etc.), charging no shipping, and still recouping a higher profit than the automatic 55% “loss” through the standard wholesale discount.
In one of my interviews with Howard Michel ARRL CEO on the ICQ Podcast, he said he ran the numbers and that it wouldn’t work out. I did not directly challenge him on that issue since it’s clearly his call. My thought was that it was a pure and simple strategy to demonstrate his new vision of “increasing value.” But enough with my recommendations, already!
However, perhaps it’s just me, but has the ARRL increased their free or discounted shipping stance in marketing publications? Like other League members, I’m sure, I received the above coupon code for Cyber Monday (after Thanksgiving). It’s FREE SHIPPING on $50 or more. That’s an incentive, especially with the new Handbook out and discounted temporarily at $40. So, I thought I’d grab another discounted book to reach $50 or more and get a FREE SHIPPING discount. On my daily driver desktop, I run Linux Mint on a Dell T-5500 8-core CPU with 72GB of RAM and a gigbit Internet service via ethernet to my commercial class switch. I rarely ever have buffering of websites from my end. Ever. But, boy, did I on this Cyber Monday order at ARRL.org! It took several HOURS for me to get the order through to checkout. I tried several different machines, in addition, just to ensure it wasn’t on my end. It wasn’t as I did a network speed operation test on getting packets to and from the ARRL.org server. It was on that end…because, no doubt, there was a boatload of customers ordering. So that’s the point of marketing offers, no? And I’m very happy to see evidence of it drawing a crowd at the virtual checkout page at the League’s website.
And, here are several more adverts e-mailed to members, all with $5 discounted shipping. So, has the ARRL been rolling out a version of this “free shipping” strategy? Well, only some offers reflect actually free shipping but a cap at $5 shipping is also a winning offer, too. I’m delighted at this marketing move by ARRL Product Development Manager Bob Inderbitzen, NQ1R. Keep it up, Bob! This increases value to members who receive the code coupons.
W9DYV Symposium Line-Up Finalized
The line-up of speakers for the Wes Schum W9DYV Radio Symposium at the St. Louis area Winterfest 2020 has now been finalized. Nick Tusa K5EF, coordinator for the Symposium, was pleased to announce that long-time boat anchor operator and aficionado Lynn Fisk, K5LYN is the final speaker.
Lynn Fisk grew up in the Texas Panhandle in the 1950s/early 1960s and enjoyed playing with radios since an early age. Amateur radio has been his life-long passion after earning his General Class ticket at age 15. Lynn was drawn to the early Central Electronics exciters developed and sold by Wes Schum W9DYV that were on the air everywhere in those days. However, he had to grow up, go to college and become a professional in Latin America History first! He eventually moved into the healthcare industry, later retired from the State of Texas in 1997 and resides in Austin, Texas.
Since retirement, Lynn has been a full-time restorer of vintage radio equipment and avid homebrewer. His more recent projects have included the design of transceiver adapters for 9MHz phasing exciters and the construction of medium-power linear amplifiers.
Lynn is extremely active in the vintage radio community while serving as one of the net control stations for both the Boatanchors Unlimited and Vintage Sideband HF nets. His nets are quite lively and often start off with a short description of how the early days of single sideband progressed in the 1950s-70s.
Nick Tusa said, “The Symposium is enhanced significantly by Lynn’s agreement to speak in the final slot on the program. His long background and standing in the ‘boat anchor’ community will supplement what our other fine speakers contribute to this year’s program at Winterfest 2020.”
K5EF also has a lengthy history with Wes Schum’s SSB and Central Electronics equipment. Nick started his adventure into Amateur Radio in 1963 as a novice class attendee at the Jefferson Amateur Radio Club. First licensed as WN5NID and later WA5RMC, Nick’s interest in Ham Radio led to an Electrical Engineering degree from Tulane University and a 40-year career in Radio/Microwave system engineering. K5EF also has a lengthy history with Wes Schum’s SSB and Central Electronics equipment. Nick started his adventure into Amateur Radio in 1963 as a novice class attendee at the Jefferson Amateur Radio Club. First licensed as WN5NID and later WA5RMC, Nick’s interest in Ham Radio led to an Electrical Engineering degree from Tulane University and a 40-year career in Radio/Microwave system engineering.
A life-long resident of the New Orleans area, Tusa Consulting Services – the firm he founded – has developed and implemented numerous public safety conventional and trunked analog and digital voice/paging radio systems throughout the US. Nick’s hobby interests – aside from Triumph sports cars – include antenna system design, homebrewing of HF equipment of all types, and the restoration of vintage radio gear (Collins, Central Electronics and TMC) and mechanical Teletype equipment.
All in all, this year’s W9DYV Symposium could be the best one yet! See videos from last year’s speakers for a flavor of the event held then in Slidell, LA. Make you plans now as this is a growing hamfest sponsored by the St. Louis and Suburban Radio Club.
Hans Solves Exploding Power Transistor with Siglent’s Help! And a New Product…
Exploding power amplifier transistors! Hmm…that’s not a good start to any ham’s operating session. But it happened to Hans Summers G0UPL as he was doing development work on the firmware (version 1.03) designed to accompany his very popular QCX transceiver sold through his company, QRP-Labs. Hans, the recipient of the 2019 Homebrew Heroes Award, was doing some firmware enhancements for CAT control of the QCX (version 1.03) to drive an external amplifier when the amplifier’s power transistor …. well, see for yourself.
But what on earth caused the explosion? Here’s where a product donated to our Hero for 2019 came to the rescue. Siglent Technologies donated their SDS1202X-E oscilloscope to Hans as part of their sponsorship. He documents how he used the Siglent oscilloscope to diagnose the power spikes that led to the complete component failure in certain circumstances on his blog.
I had switched the QCX off and on again with the toggle switch on the my front panel, rather fast. There was a bright flash and a loud bang. My QCX is connected to a 0-30V 0-20A linear-regulated bench power supply, capable of supplying a lot of power. Investigation revealed that one of the IRF510 power transistors had blown up quite spectacularly. This photo shows the result. Note that the explosion did not blow the IRF510 pins off; my safe removal strategy for replacing components, is to CUT the component out then remove the pins one-by-one from the board by de-soldering them.
Hans G0UPL
Hans explains his diagnostics further, “Investigation with my nice new Siglent SDS 1203X-E oscilloscope (thanks to kind donation by Siglent, sponsors of the Homebrew Heroes award 2019), revealed the following different power-up characteristic, depending on whether the QCX is switched on by turning on the power supply, which is what I normally do, or by switching it on at the toggle switch.
The Siglent SDS 1203X-E oscilloscope has storage features where the display can be frozen by pressing the Run/Stop button at top right. So it is possible to capture an event in “human scale time” with the horizontal timebase running at something like 100ms/div or 200ms/div; then with the display frozen you can scroll it left/right using the horizontal position control, then zoom in on the feature to be investigated, using the Horizontal Zoom knob. Once the display shows the section of waveform of interest, you can use the cursors to make precise measurements of time difference, voltage difference etc. This is very useful to examine and understand features which happen too fast to be seen or captured normally. Screenshots can be captured easily by plugging in a USB flash drive and pressing the “Print” button.”
Hans gives more technical details behind his diagnosis on his blog post but the “nasty” spikes were detected through bench testing and then diagnosing the issues producing it using his new Siglent SDS 1203X-E oscilloscope. This provides a cogent illustration of how our Hero for 2019 goes about his development and testing work for his product line. Like a fine wine, it takes time to ensure that the finished product, whether it’s hardware or a firmware update like in this instance, is working as the higher level block diagrams are intended for it to.
Hans states, “My theory is, that the first PTT signal, at power-up, when coincident with all those nasty spikes at switch on (via the toggle switch), and with the PA circuit not yet settled down (all its capacitors charged up, solid state Rx/Tx switching in stable state, etc), creates the right conditions for catastrophic positive feedback in the PA to set up a huge spurious oscillation which is sufficient to self-destruct, via the explosion of one of the transistors. This does NOT occur in my normal power-up sequence via the on/off button of the power supply. Neither does it occur if I switch off with the toggle switch, wait a second, then switch on again. It only occurred when I switched on and off quickly.” The hand diagram above illustrates his theory of the self-destructing PA transistor.
This does NOT occur in my normal power-up sequence via the on/off button of the power supply. Neither does it occur if I switch off with the toggle switch, wait a second, then switch on again. It only occurred when I switched on and off quickly.
Hans G0UPL
The solution? He says it’s an easy fix. “This situation can be resolved very simply by adding a 10K resistor (value entirely uncritical) between the RX signal and +5V. When the processor pins are floating while the processor is starting up, the RX signal is therefore pulled to +5V, until the processor has started and is ready to take over the job. In this fragment of the schematic (below) the additional resistor is shown in the yellow box. I simply soldered it between IC3 pins 13 and 14 which is convenient and easy.” The diagram below illustrates the remedy shown in yellow.
Hans told me by e-mail that, “The QCX + 50W PA is now back in order and I had 9 nice QSOs this morning, with YL Elvira ZA1EM, then E74LZ, UR5MUY, IK7XJA, LZ1HDA, OM3CAZ, R7BW, EW8CP and RW3KE.” So a 10K resistor plus the workbench savvy with a new modern oscilloscope came to the rescue.
Psst…New Product!
The 50W Power Amplifier is a new product that QRP Labs has in very late development. No, it’s actually almost ready to announce with this final change. Hans wrote me today, “Yes, This 50W PA is a new product…This 50W amp is designed as a low cost single-band amplifier for the QCX (which is my flagship 5W CW transceiver http://qrp-labs.com/qcx ).”
The description of the new 50W amplifier was sent to me earlier today and should approximate what will be on the QRP Labs website (always subject to last minute changes, of course). Hans says he is finalizing the manual now and expects an official announcement in a week or so from today. So watch his website for the official announcement. The description is in Hans’ words to me by e-mail earlier today.
This 50W Amplifier includes the Low Pass Filter. It can be built for any of 40, 30 or 20m using the supplied components in the kit and therefore covers 95% of QCX owners. Any other bands would be possible too if suitable inductors and capacitors were substituted in the Low Pass Filter.
The amp kit also includes two substantial heatsinks, which are the same design of custom-made heatsink I use in my 10W Linear kit http://qrp-labs.com/linear. Each heatsink is black anodized aluminium and sized 130 x 28mm, with 25mm fins. ALL the connectors are also included in the kit.
A key feature of the amplifier kit is that it has solid state PIN diode Transmit/Receive switching, which is fast, reliable, low cost and silky smooth quiet… it enables full break-in operation (QSK) which is very important for many CW operators (hearing the band during the tiny gaps between your own dits and dahs). Perfecting the transmit/receive switching took 80% of the development time of the kit.
I have used the prototype for over 500 QSOs over the summer on 40m, working from US to New Zealand, Japan, Northern Europe to Middle East. With band conditions in the doldrums they are, or if people wish to have a sked with a friend at a particular time and location, that little extra power can be very useful! QRP has its place, QRO does too.
The custom-manufactured enclosure kit is extruded black anodized aluminium, size 130 x 63 x 25mm and the heatsinks bolt on the top. On the rear are BNC in and out connectors, DC power connector, and a jack for the PTT signal from the QCX. It is designed to match the QCX but could easily be used for other QRP CW rigs too; it may even work well in Linear operation (with the bias adjusted correctly) but this remains to be seen and tested.
Conclusion
This is the type of bench work that great designers go through, largely unbeknownst to amateur radio operators who purchase their products. Of course, there are issues that get by even the most careful workbench. But here’s a case of precisely why the corporate donors to the Homebrew Heroes Award program have chosen to participate: to give our recipient tools to help that person to do their best work on what they do in the homebrew maker space. To see more of Hans’ illustration of this episode in homebrew development, see his website for a forthcoming video.
Here’s to you, Siglent! And, to Jason Chonko who believed in the HHA program immediately and signed his company on as a sponsor. To see this 200 mhz oscilloscope in action, go to this link.
If you’d like your company’s equipment on the workbench of our next Homebrew Heroe, contact us through the HHA website. We are accepting sponsors for the 2020 HHA now and will announce a new one soon.
Windfall for Winterfest 2020!
The opportunity for the St. Louis & Suburban Radio Club Winterfest event to work with the W9DVY Radio Symposium is a fantastic chance for us to help promote vintage radio and the history of the Amateur Radio hobby. We are looking forward to this relationship between the two groups to bring Amateur Radio operators together. We hope to have a strong attendance and we are looking forward to hosting the great Symposium forums. Rebecca Carroll, KC9CIJ – Winterfest 2020 ChairThe Winterfest is located in The Gateway Center, in the shadow of the St. Louis Arch on January 24-25, 2020. No winter weather worries inside the Center! Lots of hotels at various price points nearby. And there are many other activities, such as Contest College with 10+ hours of forums, presentations, Q&A and contesting discussion, as well as the DX & ARRL Banquet and…the ARRL Midwest Conference with CEO Howard Michel and other staffers from Newington. Ward Silver NØAX is the Banquet speaker along with Craig Thompson K9CT on the Pitcairn VP6R DXpedition. Flex Radio Systems will be there as a vendor with their newest SDR technology, among other popular vendors. See the Winterfest website for more details. There is a lot going on, competing with most any regional ham fest in the U.S.
- A High Performance SDR Receiver for the Ham-Bob Nichols W9RAN
- HF Receiver Performance-Rob Sherwood NC0B
- Understanding of Human Speech Articulation-Dr. Bob Heil K9EID
- The Collins S-2 Line History and Evolution-Dave Beckler N0SAP
- Wes Schum (W9DYV) and Central Electronics-Nick Tusa K5EF
- Drake T4XC: Low Power Output and Why-David Assaf W5XU
- ARRL, AM and the story of the Gates BC-1T-Bob Allison WB1GCM
- Another “major homebrewer” presentation is pending
Planning a successful, and growing, hamfest takes vision and the willingness to engage “over the transom” opportunities. You might be surprised at the reticence of some well-known hamfest Chairs and Committees to see beyond last year’s program. Frank Howell K4FMHPlanning a successful, and growing, hamfest takes vision and the willingness to engage “over the transom” opportunities. You might be surprised at the reticence of some well-known hamfest Chairs to see beyond last year’s program. Online sales are eroding the ROI that major manufacturers, their resellers, and the small ham radio business companies get by committing thousands of dollars just to get to a hamfest. Individual sales through boneyards can yield surprise inexpensive purchases but, on the average, hamfests face a similar battle with eBay sales, too. It is programs—the continuing education of hams who spend money to attend a hamfest—that bring’em in, repeatedly over the years. And the Winterfest 2020 team is doing that in spades.
Oh, They Should’ve … Here’s Why and Why Not on the QSX
How often have you seen into the thinking process of the development engineering team for an amateur radio manufacturer? Or an industrial test and measurements manufacturer of devices used frequently by amateur operators? In the latter case, the HP Journal was (and still is for vintage equipment) a key source for their line of equipment and often had an in-depth article from the engineers who designed one of their popular test devices. Less so but often with the Tek Journal, too. I always see if there’s a “design article” for any HP or Tek vintage equipment before I make a purchase. While MFJ Enterprises frequently gives factory tours, even for a single visitor, Martin Jue rarely gives public disclosures of the thought process of a device. At least, not until it’s well into production and sales.
But Hans Summers G0UPL, recent winner of the Homebrew Heroes Award for 2019, has done just that! In the October issue of QRP Quarterly (Vol 60, Number 4: 24-38), Hans weaves his thinking and design choices for the SSB QSX multiband, multimode 10-watt QRP transceiver. He’s been publicly discussing the concept since 2017 but rarely do we get this level of detail and insight for a major transceiver release. Oh wait. It’s not a product of one of the major manufacturers so what makes it a major product?
Review the QRP-Labs website on the QSX for the interim specifications and feature set. And pay attention to the projected price. Now, let’s revisit the reticence at calling it a major product release. Block diagrams, schematics, mock-up designs, and the pricing-performance choices going into Hans’ decision matrix for each element of the forthcoming rig are there. Even the case and the choice of no hardware volume control! And the choice of a soft switch for power on and off. The inclusion of several test equipment circuits built directly into the transceiver package ramps up what other manufacturers have included. And did I mention that the target price is $150 USD?
Ashar Farhan made a real splash in the QRP homebrew space when he released the Bitx40 ($59USD) and uBitx ($130USD). There is a small army of builders, modders, and third-party add-ons and case makers surrounding Farhan’s products. But reading the target specifications for “just a little bit more” at $150USD on the QSX QRP transceiver (including a nice case), it will set a new bar for the value proposition in the QRP market place!
And who knew how much the inclusion of a “simple” potentiometer for power on/off and volume control could impact the overall design and cost for a multiband transceiver? If you read this article, you’ll be somewhat shocked and amazed at how the designer’s careful analysis of his product target goals factored into the decision to just not include one. But that’s only one of the interesting twists and turns in this intriguing article on the design of the QSX transceiver.
Read the article and see if you agree with my assessment. QRP Quarterly is edited by Mike Malone KD5KXF. It is the publication of the QRP Amateur Radio Club International with an annual subscription price at $25 USD for domestic subscribers and $28 USD for international subscribers. The QRP-ARCI sponsors the Four Days in May Symposium held in conjunction with Hamvention in Xenia, OH. Hans G0UPL is also a member of the QRP Hall of Fame.
Source: HomebrewHeroes.org
The market shall see what the final version, performance, and exact price will be. Reviewers will leave no stone unturned in putting the QSX through it’s paces when it’s available for retail purchase. But very rarely will buyers know as much about a transceiver’s design and why it was so as with the QSX. The snarky reviews that we almost always see of why didn’t “they” do this or that in a rig will almost all have been answered well in advance of the official release of the QSX. While “they” usually represent an engineering design team, QRP-Labs is staffed by one, Hans G0UPL, Hero 2019.
