KB6NU's Ham Radio Blog

KB6NU's Ham Radio Blog

FDIM

Dayton Hamvention 2026: Day 2, Thursday, May 14

By Leave a Comment

QRP-ARCI logo.
Four Days in May is an activity of QRP-ARCI.

Day 2 started out pretty early. The Four Days in May (FDIM) seminar starts at 8 am!

After a short drive from my hotel, I arrived at the DoubleTree Hotel a little after 7:30 am, expecting to sail in and claim a seat. I was, however, was surprised to see a line snaking down one of the hallways. Apparently, they weren’t letting people in yet.

As I walked down the hallway to take my place at the end of the line, I came across my friend Tom, W8TJB, who graciously let me take cuts. As it turned out, there were plenty of seats, though, so that was not a big deal. Here’s a short description of the talks I heard:

  • A Homebrewer’s Journey: How I got to where I am. Harold Smith, KE6TI, gave the first presentation of the day. He detailed his journey, from his high school days in the early 1960s to today. Harold’s talk included a lot of useful tips, but my big takeaway was, “When you’re homebrewing, you’re building for yourself.” With that in mind, Harold advised to not worry so much about how a project looks, or even how well it works. Focus on the enjoyment you had building something and what you learned from working on it.
  • Life is NOT Too Short for QRP if You Know a Few Tricks. Anthony Luscre, K8ZT, was responsible for this talk. He provided many, many tips for successfully operating QRP including how to select equipment, what antenna to use, what bands top operate, what modes to operate, and what times to operate. He also gave quite a few tips on operating technique. One tip that I plan to follow up on is his tip to use the 4X4XM Propagation Tools to better understand propagation.
  • The CFT1: the design philosophy and lessons in good user interface. Jonathan Kayne, KM4CFT, a young ham who recently graduated from Virginia Tech, told us the story of how he came to design the CFT1, a five-band, QRP transceiver. In this very interesting talk, he detailed his reason for designing the radio (a very noisy QTH which drove him to operate portable) and the entire design process. I enjoyed this talk so much that I thought that I might even buy one of his radios, but the kit cost $320, and since I still haven’t finished building my QMX, I decided not to.
  • Post-Hurricane Helene: The Role of Practical Preparedness and Community in Emergency Communications. Well-known QRPer, Thomas Witherspoon, K4SWL, lives in the mountains in western North Carolina, right in the path of Hurricane Helene. He spoke about how the hurricane affected him and his family, but perhaps more importantly, how the people of his community bonded to get through the crisis. As he was talking to an audence made up of hams, he talked quite a bit about the importance of communications in keeping that community together. “In a disaster,” he said, “communications is not just about passing information. It’s about holding a community together when everything else falls apart.”
  • Learn CW Like a Boss. In this talk, Jerry Weisskohl, AC4BT, gave us some tips on how to improve our ability to send and receive Morse code. He strongly recommended the use of Morse Runner and detailed  how he used the program to get better at receiving.
  • Vibe (AI) Coding for Radio Amateurs. AI is all the rage these days, and Dr. Stewart Bryant, G3YSX, showed us how we might use it for developing software for amateur radio projects. After introducing some of the concepts behind the current AI chatbots, he gave some examples of its use, including coding a VFO using an AD9851 and developing a GNU Radio script to display the spectrum of an audio input. Bryant is very big on the technology and urged us all to try it. I may just do that.

I say this every year, but FDIM really inspires me to be more of a builder/homebrewer/hacker. Maybe if I get more serious about it, I could even give a talk next year.

Let’s hit the park!

After sitting through these six talks, I was getting a little antsy, and seeing that the last two talks didn’t really interest me all that much, I decided to escape and activate a park. The park that looked the most promising was the Dayton Aviation Heritage National Historical Park (US-0732). At first I was a bit confused about the actual location of the park. The park actually consists of a couple of different locations, including the Wright-Dunbar Interpretive Center and the Huffman Prairie Flying Field. The POTA map shows the location of the Huffman Prairie Flying Field, which is out near Fairborn. Fortunately, I chose to go to the Wright-Dunbar Interpretive Center, which is in the Germantown section of Dayton. There is a nice, little park there next to the museum, which is perfect for POTA.

Man sitting in front of a radio on a picnic table.
It was a beautiful day for a POTA activation at the Dayton Aviation Heritage National Historical Park.

As I pulled into the small parking lot, I noticed a ham (whose call I don’t remember, unfortunately) there already. I got out of the car and walked over. He was trying to make some contacts with an Elecraft KH1 and and AX-1 antenna. He said that he wasn’t having much success but encouraged me to set up and give it a try, so I went back to my car and got my stuff. We chatted a bit more while I was setting up, and he seemed interested in my doublet antenna. After I got on the air and made a couple of contacts, he left.

Not long after, a group of four hams—N3AIR, N3VQH, K3MET, and KC3RMC—exited the museum and walked over. They had driven in from Pennsylvania and were taking in the sights. They were a fun bunch. We did the HT thing, and I got a park-to-park QSO with all of them on both 2 meters and 70 cm. Then, one of them took the picture above. I wish I’d gotten a selfie with them all.

We were joined by another ham—a W6—and they chatted while I operated. Like the first fellow, I didn’t have a whole lot of luck on 20 meters, but when I switched to 40 meters, I started making quite a few contacts. That’s one advantage of having a full-size antenna like my doublet.

After the Pennsylvania contingent took off, I operated a while longer by myself. All in all, I managed to make 45 contacts in about an hour and a half. Not a bad afternoon’s work.

Meeting the CWops

Two older men and a woman smiling at the camera.
At the CWops Dinner, I met, Howard, W1HRB, and his wife, Barbara.

My next stop was the CWops dinner. I met a lot of great operators there, many of whom I’ve worked on the air and/or swapped email with. Just before dinner was served, I found a seat between Steve, KJ5T, and Howard, W1HRB. Howard, and his wife, Barbara are shown in the photo above.

Howard, as it turns out, lives not very far from me, and I tried to recruit him to operate at one of our Field Day stations. He was unsure of his availability for Field Day, but said that he’d try to come to one of our club meetings. I think he’d make a great ARROW member, so I really do hope he comes to a meeting.

The dinner broke up about 9:30, and I head back to the hotel to get some rest for Hamvention the following day.

Dayton 2024 had it all: Four Days in May

By Leave a Comment

On Thursday, May 16, I attended Four Days in May (FDIM), an event put on by the QRP Amateur Radio Club International (QRP ARCI). The first FDIM was held in 1996, and QRP ARCI has held it every year since, excluding the Covid years. This year, nearly 300 people attended the event.

Like the name implies, there are FDIM events on Thursday, Friday, Saturday, and Sunday, but the main event is the series of talks on Thursday. These start at 8 am and run until 5 pm. This year, the talks included:

  • The Construction and Use of a WhoZat by Jack Purdum, W8TEE. Jack is a retired professor from Purdue University, a frequent speaker at FDIM, and the designer of many microcontroller-powered ham radio projects, including transceivers and antenna analyzers. This year, he talked about his latest design, the WhoZat. WhoZat is a portable, battery-powered device that allows an operator to type in a call sign prefix and obtain information about the country associated with the callsign. It will give you the country name, and the azimuthal bearing from your location to that country. One of the takeaways from this talk is that the WhoZat is powered by a Raspberry Pi Pico, and Jack encouraged everyone to consider the Pico for future projects because it has more computing power and more memory than most Arduinos.In addition to talking about the WhoZat, Jack was promoting his latest book, Digital Signal Processing and Sofware Defined Radio. It’s available on Amazon for $45.
  • Top 10 Junkbox Projects by Hans Summers, G0UPL. Hans is the genious(?), madman(?), entrepreneur(?) behind QRP Labs. In this talk, he extolled the virtues (as I have done) of a well-stocked junkbox. The project that resonated the most with me is the one-tube transmitter.The reason it resonates with me is that I’ve been threatening to build one for years myself. Hans actually did it, though. In fact, he made his first QSO with a transmitter he built from an ECL82 tube.At the end of his talk, Hans gave a little plug for his newest transceiver, the QMX+. The embedded SDR rig covers 160 – 6m, in a slightly bigger form factor than the QMX, for only $125. It’s incredible, really.
  • zBitx–A Portable Station for the CW Operator by Ashar Farhan, VU2ESE of HF Signals. In this talk, Ashar described his zBitx, a portable CW/FT8 SDR transceiver. This isn’t a radio that Ashar is selling (yet!), but it does look like a complete design. And, of course, that design is completely open source, something he ribbed one of the other presenters about.
    A small radio with a smart phone user interface.
    The zBitx is a very small, portable CW/FT8 radio that uses a smart phone for an enhanced user interface.

    This radio is powered by a Raspberry Pi, specifically the Raspberry Pi Zero 2 W. This module costs $15 and runs Linux. Ashar says, “If Arduino was a matchbox RC car, this Raspberry Pi is an Airbus A380, both in terms of size and speed. It can run WSJT X, fldigi, and full-stack SDR.” The radio also takes advantage of the WiFi capablity of the RPi. There’s an app that runs on a smart phone that acts as a front panel.

    At the end of his talk, instead of flogging a product, Ashar passed out a small PCB assembly called the sBitx Hat. Designed to plug into a Raspberry Pi, it includes an Si5351 clock generator and a 96 kbps, dual-channel audio codec. It looks it will be a fun thing to play with.

  • Adventures of a QRP Evangelist by Cliff Batson, N4CCB, proprietor of the QRP School YouTube channel. Cliff gave us a primer on QRP operation and on how to make YouTube videos. He encouraged us all to go out and make videos. I’m not so sure about this myself. It seems to me that there is already too many ham radio videos to watch.
  • Amplifying Your Adventures, Minimizing Your Power by noted YouTuber Tom Witherspoon, K4SWL. In his presentation, Tom concentrated on the personal and operating aspects of QRP, not the technical. The conclusion published in the proceedings does a good job of summarizing his talk. It reads, “Since my journey into ham radio began in 1997, I’ve encountered countless naysayers proclaiming, ‘That won’t work’ or ‘Life’s too short for QRP.’ These discouraging words often came from individuals who lacked firsthand experience in the field. Rather than accepting the pessimistic views, I’ve treated them as a checklist of challenges to overcome. my approach has been simple: get out there, experiment, and fully immerse myself in the moment. It’s through this hands-on exploration that I’ve discovered the true joy and potential of QRP operations.”
  • Designing the Elecraft KH1: From Vision to Reality by Wayne Burdick, N6KR. Wayne certainly needs no introduction. His talk concentrated on how he made some of the decisions he made in designing the Elecraft KH1 hand-held HF transceiver. It was a great talk that gave quite a bit of insight into the design process. Personally, I’m not sold on the KH1, but Elecraft can’t make them fast enough, so I guess that tells you how valuable my opinion is.
  • The Amazing Thermionic Valve by Greg Latta, AA8V. Greg is a professor emeritus of electrical engineering from Frostburg State University. He delved into some of the theory of how vacuum tubes work and some of the practical applications.
  • Stealth Operation from Hotel Rooms and Other Unlikely QTHs by Ross Ballantyne, VK1UN.

Unfortunately, Ross was unable to present, either in person or via Zoom. According to the paper in the proceedings, Ross was part of several peace-keeping missions to remote spots around the world. On these trips, he operated from many hotel rooms and gained quite a bit of experience doing so. For example, he writes that virtually all of his antennas are made from wirewrap wire, which he gets from Ali Express. To couple the wire antenna to the transmitter, he uses a Z-match tuner or a modified Z-match tuner called the FRI match ATU. It’s a shame that Ross wasn’t able to adress us in person, as he sounds like quite an interesting fellow.

A walk with VU2ESE

After the talks, I decided to take a walk and stretch my legs. Just as I got to the street, I ran into a friend of mine, Arun, W8ARU, and Ashar, VU2ESE. We decided to walk together, and ended up walking about a mile and a half or so.

Arun and Farhan have been friends for many years. In fact, Arun hired Ashar to work for a company that Arun owned when he lived in India. (Arun now lives in Ann Arbor, MI, which is how I got to know him.) Arun once told me the taught Farhan how to solder. I confirmed that story at Hamvention last year when Ashar visited the ARDC booth.

In addition to all his development activities, Farhan recently joined the board of directors of Amateur Radio Digital Communications (ARDC), the private foundation that I retired from last May. We had a great chat about the future of ARDC and amateur radio in general, among other topics. It will be interesting to see in which direction the new board members take ARDC.

Vendor Night

Thursday evening, FDIM holds Vendor Night. It’s a great deal for vendors. There’s no charge to participate as a vendor, and it’s a lot of fun. A couple of years ago when I did Vendor Night, I also shared a booth with the Dayton Makerspace on Friday and Saturday at Hamvention and ended up selling more books in 2 hours at the FDIM Vendor Night than I did in 2 days of Hamvention.

This year, I sold about $150 worth of books. What was even better was meeting everyone, including those who have used my books to get licensed or to upgrade. For example, Tom, K4SWL, came over and shared his story with me.

He said that one year his wife said that she would also get her ticket as an anniversary present. He gave her my study guide and ten days later, she had her license. How cool is that?

Kudos to QRP ARCI for another successful FDIM. If you’d like to get a copy of this year’s proceedings, you can contact them by emailing [email protected] or [email protected]. QRP ARCI also has some other goodies, if you’re interested, in their Toy Store.

Dayton 2016: QRP-ARCI’s Four Days in May (FDIM)

By 7 Comments

dayton-2016For the past sever years, I’ve been attending the QRP-ARCI‘s Four Days in May (FDIM), which is held in conjunction with the Dayton Hamvention. FDIM includes a number of different events, the biggest being the seminar held on Thursday, the day before the Hamvention.

The seminar features a number of talks, and this year, the lineup included:

  • Elecraft – Shrinking the Multi-Mode HF Transceiver, Eric Swartz, WA6HHQ. Elecraft likes to introduce new products at FDIM, and this year was no exception. The introduction of the new KX2 got this year’s FDIM off to a rousing start. I actually got to see it up close and personal, as one of the field testers, Bruce, N7RR, was sitting two rows in front of me, and he passed his unit around for folks to have a look. It’s a pretty cool little radio, at about half the size of a KX3. To make the radio smaller, they did have to make some compromises, though. The KX2 only covers 80m – 10m (no 160m or 6m), and there’s not an IQ output. Even so, lots of folks in the audience were buzzing about it.
  • WSPR and the Raspberry Pi, Scott Cowling, WA2DFI and Zoltan Doczi, HA7DCD. To be honest, this talk didn’t do much for me. WSPR is kind of cool, and building an add-on board for the Raspberry Pi to run it is kind of cool, but I still can’t work up a lot of enthusiasm for it.
  • 2016 – The Year of the Portable Operator From IOTA to SOTA to NPOTA, Guy Hamblen, N7UN. This was a great talk, and it’s gotten me interested in doing some NPOTA activations this year. Unfortunately, there aren’t many NPOTA sites that I can activate in SE Michigan. It’s pretty much the same for SOTA activations. Michigan is flat, flat, flat.
  • Occam’s Scrip – the minimalist measurement mindset, Paul Darlington, M0XPD. Despite the need to explain the title of his talk, and his use of flowery language (well, he is English, after all), I mostly enjoyed Darllington’s talk. His theme was certainly right on. QRP is all about minimalism, and that mindset should translate into how we think about RF measurements as well. I would offer a caveat, though. Einstein is credited with saying, “Everything should be as simple as possible, but not simpler.” I’d paraphrase that, “If something’s too simple, it simply won’t work.”
  • Troubleshooting and Repair Techniques, Mike Bryce, WB8VGE. This talk was a chronicle of Mike’s adventures in repairing old equipment. It was a real hoot, and almost the opposite of M0XPD’s talk. Mike used decidedly more down-to-earth language than M0XPD, in a flat midwestern accent. Lots of good tips for fixing various and assorted problems.
  • Thermatron Homebrew Ideas and Techniques, Grayson Evans, TA2ZGE/KJ7UM. Aside from a few new wrinkles, TA2ZGE gave this talk about building circuits with tubes (devices that he insists on calling “thermatrons”) at FDIM a couple of years ago. It was fairly interesting, but having heard this talk before, I think that I’d rather have heard something else.

The only other FDIM event that I participated in was Vendor Night on Thursday evening. I didn’t sell as many books as I’d hoped, but I did make contact with several ham radio instructors. I also got to meet several readers, and that was fun.

In addition to those, I had a kid come up and take a look at the General Class study guide. He told me that he was going to take the General Class test the next day and was wondering if he should buy the study guide. I asked him if he was passing the online tests, and when he answered yes, I told him to save his money.

He came back some time later and asked about taking the Extra Class test. He said that he hadn’t really studied for it, but I told him to take it anyway. It wasn’t going to cost him anything, so why not? I heard later that he passed the test.