CQ Boomer
OK, I know you're not all Boomers
Hello Boomers and Boomers-at-heart! I come back to you with a update after a bit of an unexpected hiatus. I don’t like to try to use filler for my posts here, so I haven’t felt like there’s been much worthy of posting about here. But I realized that it had been far too long since I’ve posted and I wanted to let you know that things have been happening, even if it’s not as quickly as I would like.
A Few Personal Updates
As I previously told you, about six months ago I was hired onto a full-time position at A-dec as a Test Technician. So far I’ve had to learn a lot, but it’s been an interesting and rewarding job, and I’ve passed my probationary period. However, I haven’t worked a full-time job for a corporation for many years, so it’s been a bit of a difficult transition for me, after a long time of mostly making my own schedule. Without getting too whiny, I wanted to note that it’s taken me some time to figure out some semblance of how to manage my time when I don’t have nearly the slack in my schedule that I used to have. Between working full-time, a fairly long commute, my ongoing projects that I have to complete here on our new estate, and the need to have a bit of family time as well, I’ve had some challenges in finding the time to work on the projects that I talk to you about here.
However, that doesn’t mean I haven’t been working on them. As I said in my last posts, I would find a way to keep moving forward, and I have…just at a slower pace than I like. I do try to get snippets of time devoted to advancing the various unfinished projects on the bench here. So without further ado, here’s what I’ve been working on these last few months.
Four Days in May and Hamvention 2025
The biggest thing on my plate this spring was all related to my invitation to speak at the FDIM 2025 symposium on the new rig design that I’ve been cooking up, especially related to the mixer part that I chose for the receiver: the MAX2681. I was in a bit of a rush to not only get the rig in a reasonably-working state, but to also document all of my work fairly rigorously, write a white paper about it for the FDIM Proceedings book, and then create a compelling slide deck for my presentation.
It was my pleasure this year to be able to take my youngest son Eli along with me, who has shown some interest in engineering. We were also fortunate to have the company of close friend Eugene AB4UG, who was making his first trip to both FDIM and Hamvention. This was my fist time going since Eli was a baby and Hamvention was at Hara, so I was looking forward to seeing the upgraded facilities in Xenia.
I’ll spare you a long after-action report, but we all had a great time. My talk at the symposium went decently and seem to be fairly well-received (Eli said he only heard one heckler behind him). You can view my talk here:
I was pretty wiped out after the symposium, so unfortunately I didn’t spend a lot of time at FDIM vendor night, but I did get to introduce myself to and have short conversations with various HamTubers that I enjoy, including K4SWL, K6ARK, N6ARA, and KM4CFT. Even with my social anxiety, that was very enjoyable.
On Friday, we hit Hamvention hard, especially the flea market. I’m pretty sure we walked past every booth in the flea, which is no mean feat. During our flea walk, I managed to purchase the tools needed so that Eli could participate in the W1REX buildathon at FDIM Friday evening. There were a lot of good commercial vendors in the halls, and the whole place was jam-packed. It’s wonderful to see that our hobby is still thriving after years of doomsayers predicting it was going to fall off.
Friday evening back at the Holiday Inn Fairborn, I helped Eli to work on the TTL challenge transmitter that W1REX sold for the buildathon. Things were going great until Eli accidentally burned his finger on the iron, which kind of killed his desire to finish. Understandable. I finished it for him and let him know that we’ve all burned ourselves on the iron.
The majority of Saturday was spent by the three of us at the National Museum of the USAF, which was a first for all of us. I’m sure many of you who have been to Hamvention have already done it, but if you haven’t then I highly recommend it. Just plan on being there a good portion of the day. After that, we went back to Hamvention for a few hours to wander the vendor booths a bit more and check if we won any prizes. That evening we attended the FDIM banquet and had nice chats our tablemates. What was really crazy was that Eli won one of the major prizes: a Bioenno portable PV panel! I ended up having to check it on our flight back, as it wouldn’t fit in my suitcase, but it was really awesome to see him get excited about winning something big.
Project Yamhill
I definitely still intend to see Project Yamhill to the finish line. There are a lot of parts of it that require development, and I’ve decided to break that development into other projects that I also have in my queue, where I can then import that work back into Project Yamhill. For example, I need to come up with a good solid transceiver architecture before I can move forward with much of the final block design in Project Yamhill. My MAX2681 transceiver was a way for me to not only investigate a new mixer IC, but to nail down a transceiver architecture. I also need proper keying code, hence my work on EtherKeyer Mini. All of these other projects may look as they are unrelated, but they definitely are not. Once these projects are near complete, I’ll be incorporating my learning and code back into Project Yamhill. Things are definitely not dead on this front.
Other Etherkit Projects
So speaking of those other projects, let me tell you how they’ve been going. Regarding the MAX2681 transceiver, when I’ve had bits of free time I’ve still been using it on-air, to make sure to shake out any more bugs and really get a solid understanding of how it performs and any of its shortcomings. I’m already pretty far into the schematic capture for a 5-band version of this radio, and I intend to get to work on the PCB layout as soon as that’s done. The thing that’s been slowing me down a little on the schematic capture side is the uncertainty about some of the circuitry that I haven’t prototyped yet, mainly related to the multiple band support. But that’s almost done and I hope to have more news for you in about a month or so.
Before Hamvention, I did another spin of the EtherKeyer Mini PCB to fix a fatal flaw in the previous design. I want to be able to power the keyer off of a CR2032 coin cell, which an ATtiny microcontroller theoretically should be able to do if you can put it in sleep mode when it is not being actively used. The problem with the old version is that I was using an 8-pin microcontroller, and I didn’t have enough GPIO pins for all of the button inputs, paddle inputs, and keying output that I needed. So I used a trick where I used one analog input to read all of the buttons. That works fine, but by waking up the microcontroller from sleep mode to read the ADC every few hundreds of milliseconds consumes a lot of current relative to how much the is consumed in sleep mode. The long-term effect is that the battery drains a lot faster than it should otherwise.
So for Rev C of EtherKeyer Mini, I switched microcontrollers to an ATtiny3226, which has more GPIO pins and has a more modern architecture. This part doesn’t come in a DIP package, but it does come in a reasonably easy to solder SOIC package, which isn’t bad even for those who don’t usually solder SMT. Since every IO is now on its own digital pin and can use a digital interrupt to wake from sleep, the sleep mode current consumption is where I would expect it to be, and the device can sit for years without using an on/off switch.
The other big change that I made was to the serial interface. To put it bluntly, Dupont header pins make for a lousy physical interface, so I ended up changing the paddle input from a TRS jack to a TRRS jack, which allowed me to double up the functioning of the jack. In addition to the normal paddle functions, you can also plug a TRRS cable from an appropriate UART adapter and access the onboard serial port and flash the firmware. I also created a new adapter board that uses a CP2102 IC to provide a USB-C 2.0 connection to the TRRS cable, as shown below.
I ended up ordering these assembled from the PCB fab house, which was a lot nicer than doing that work myself.
What’s Next
Since the weather is finally nice around here, I do have to spend some time on outdoor projects around the property while I can, so some of my free time is going into that. My radio work is going into getting EtherKeyer Mini to the finish line and then getting a Rev A PCB of the multiband MAX2681 transceiver off to the fab. I hope I can get one of those in hand before summer is over, so that I can take it out for some field ops.
While I won’t be posting at the same rate as I was last year, I’ll do my best to post more frequently going forward, even of my posts are a bit smaller. You deserve to get updates and I do enjoy sharing them. I just have to learn to be less of a perfectionist.
Thank you all for your continued support!
Great presentation Jason. Many thanks for the update. Best to you!
Lid
That was a very nice FDIM presentation! Thank you for the info and measurements, especially in the HF range (I guess all the cool kids are playing in the VHF/UHF region...)