State of the 'Stack 2024
Looking back over the past year
As Project Yamhill nears actual physical implementation, it’s time to start building some more real-time, two-way communication. We’re starting to get some beta testing and discussions going! If you’d like to participate in Project Yamhill chat, please click on the link below. Thank you!
Just a few miles from our place:
It’s hard for me to believe, but it’s already been more than a year since I launched this Substack! It started with this first post, which was a little background on me and a manifesto on my vision for Project Yamhill:
Here’s what I said about this ‘stack in my first post:
I’m setting myself a goal and recurring task in my calendar to write at least one useful and informative paid subscriber post per week as well. I will be keeping my blog Ripples In The Ether focused more on personal posts, and most of the technical stuff will be posted here.
Since the inception of this publication, I’ve posted 32 entries, with a bit of a slower start, then I was able to post nearly every week once I got our big issues with moving to our new property sorted out. Although my posts aren’t long-form essays, I did endeavor to provide some substantial content for each one, as much as was possible. On the publishing front, I think I’ve succeeded in consistently providing updates and content for my readers over this last year.
I’m enabling paid subscriptions now, but I will not be paywalling any content until I have at least one full learning module published. Most likely that first learning module will be a receiver so that anyone can build it, licensed ham radio operator or not.
I’ve decided that I won’t paywall any of the core Project Yamhill material ever. The only thing that will occasionally be paywalled will be “extras” such as as technical analysis posts that do deeper dives into certain issues, but those will be sparing and will take a back seat to the main Project Yamhill content. I have had a decent number of people step up to financially support this effort, which is extremely helpful, since I have already sunk a good amount of money into prototype components, some new test gear, and initial PCBs. My most sincere thanks go out to both paid and free subscribers of this publication! It’s gained a good amount of support over this past year, and it feels like there’s some real momentum going into the actual implementation of Project Yamhill.
Project Yamhill Status
As a refresher, here is my initial post about the Project Yamhill architecture:
The list and functions of the block modules haven’t really changed at this point, and all of the block modules that I’ve implemented so far are working as expected (with one small exception, that I’m working on correcting). I’ve been able to construct a basic direct conversion receiver with the first tranche of boards, and I think the entire concept appears to be sound. Not that there won’t be more difficulties when trying to implement more complex radios, but I believe these can be overcome.
As I anticipated, the Front Panel PCB is the most complex and troublesome part of this project. My first spin of the PCB was a pretty big failure, but I’ve been diligently testing every circuit and documented the needed fixes, which will be implemented in a new PCB spin soon. These include fixing some incorrect components footprints, adding at least one more op-amp audio amplifier stage, changing where the AF low-pass filter will go in the audio chain, adding an audio AGC detector, and reworking the power conditioning circuits for all of the digital circuits. Unsurprisingly, since this is the most complex circuit in all of Project Yamhill, it will require the most refinement. But once I get this nailed down, I’ll be over what is probably the largest hurdle in this entire endeavor.
All in all, Project Yamhill is still shaping up to work pretty much as I anticipated in my initial architecture document. I know there’s still a long way to go in order to get all of the different radio projects implemented, but once the first one (the direct conversion receiver) is completed, there will be a successful roadmap to follow for the rest of Project Yamhill.
Personal Stuff
From my first post:
Hello! My name is Jason Milldrum and I hold the amateur radio callsign NT7S. I’ve been interested in radio for a good portion of my life, and I’ve been a ham radio operator since 1992. I worked at Tektronix on the Real-Time Spectrum Analyzer line after receiving my AAS EET degree, and then struck out on my own. I own the open source amateur radio company named Etherkit (currently dormant) and have had my own personal blog documenting my ham radio activities for about a decade.
My family, including my wife Jennifer and sons Noah and Eli, have recently moved to our country property in the gorgeous wine country of Yamhill County, Oregon. You can read more details about that here. The disruptions to the supply chain from the response to the COVID pandemic dealt a serious blow to my business, so I put it on hiatus in order to regroup and put energy into escaping the city and moving us to rural property. Now that this difficult task is nearly complete, I’m ready to get back to work.
When I wrote that, we were still living in a travel trailer on our property, waiting for our house to be completed, which wasn’t a certainty at that point. Without getting into the very long details of the ordeal, we did eventually get our house and our family was able to start occupying it in June 2023. Once that happened, I was able to devote much more time to Project Yamhill.
Our boys have settled into their new school and have made a ton of new friends, which has been so beneficial to their physical, mental, and emotional health after the hellscape of isolation that were the COVID lockdowns. Jennifer and I are also becoming a part of the community here, making new connections, getting involved with our boys’ extracurricular and school activities, and learning about all of the amazing small local businesses there are to support in our area.
Soon after I wrote that first post, I got a part-time job which keeps me busy a couple of days out of the work week, so I typically get three work days in the middle of the work week, and I often work on Project Yamhill on the weekends if there aren’t other obligations.
Etherkit
I’m going to be officially relaunching Etherkit as soon as I have a product or two to put up for sale. With any luck, EtherKeyer Mini will be in a state ready to sell soon (I’ve already had one successful beta test build, and the firmware needs just a bit more work to be feature complete). I’m also looking at a way to bring back the Si5351A Breakout Board that was quite popular. Previously, I was hand-assembling them(!) but that’s not a realistic way for me to do it going forward. So I’m going to investigate having a manufacturer place all of the SMT components for me, so that it can be sold as a partial kit as before. I will definitely post further news about the fate of Etherkit on this publication and my personal blog when there’s significant new info.
What’s Next
I mentioned in my last post that the muting/keying of Party Line 80 was the last thing that I really needed to work out in order to get it in a fully-functional state. I’ve been investing quite a bit of time and effort into investigating how to fix the mildly-unpleasant keying sound. After lots of oscilloscope measurements, I have an excellent idea of how the keying artifact is happening, and even where it is originating, but I haven’t figured out how to correct it yet. The thing is, if my mute circuit would work perfectly in cutting off the audio exactly when the key is pressed, there would be no problem, but of course nothing works ideally in real life. So I need to either fix the source of the impulse that gets into the front of the audio chain, or make the mute circuit engage faster than it is now. Realistically, I think my best approach is the latter, so I’m going to be breadboarding some various mute circuits and feed them with an audio tone from my AWG with a DC offset, which should emulate the conditions at the output of the AF PA.
I’m still looking for people who would like early access to EtherKeyer Mini. If you are a CW op and don’t mind doing some occasional firmware updating, it would be a fun little project. Get in touch with me (link at the top of the post) if you’re interested.
I’ve got to purchase one IC for the Front Panel PCB that I need to finish testing all of its circuits. I had a bag of them around here but they seem to have disappeared, so I have to buy them again. Once those are here and that circuit is confirmed to work (or not) then I’ll be able to start on the Rev B spin of the Front Panel PCB.
Finally, I’m going to change the design of the audio low-pass filter board a bit, based on the recommendation of a reader in the comments. Instead of using a single quad op-amp package, I’m going to rework the PCB to accept two dual op-amps instead. It’s hard to find quality quad op-amps in DIP packaging. I’d like to keep the DIP footprint, but I may make a dual-footprint design so that SOIC op-amps can be used as well, since you can get a lot of quality, low-noise op-amps in SOIC.