mcHF – a.k.a. what I wish I’d done

90 years ago, amateur radio operators built all their own stuff. There wasn’t any other way; no one would or could do it for you, and one really had to be committed to build a station with the technology of the day, not to mention the costs involved. You had to understand how every component worked, and how to make a radio “system” work with minimal to nonexistent test equipment.

After WWII, more commercial gear became available, and useful stations could be cobbled together using surplus military gear. An operator didn’t have to build from scratch anymore, but they did still have to understand their gear in detail so as to make it work within their legal operating bands.

Kits were still an option into the 60s and 70s, as tube gear transitioned into the semiconductor age. Perhaps an operator didn’t understand how the equipment worked at the outset, but by building it, he would at the end. Kits are a difficult business model, however. If your customers have trouble putting your products together, it will cost you in terms of technical support, and in terms of reputation. Because of this, and perhaps because of attention span compression in the modern age, kits come and go.

From the 70s into the 80s, amateurs who built their own gear (and who truly understood their own gear) became increasingly rare. So many simply purchased commercial gear and became “appliance operators” as the options declined. More educated and motivated operators might fix broken gear as a way to build a station cost-effectively. Into the 90s, the transition into higher levels of silicon integration and surface-mount technology made the equipment nearly unserviceable except for the most committed folks.

In the early 21st century, though, bright spots are entering. The internet makes all sorts of information accessible to anyone that wants to look for it. Open source software (where the source code and licensing are available to anyone that wishes to work with it), and the culture that came with it, opened the door to open source hardware. EDA/design tools are now sometimes available for free, whereas they used to cost monumental amounts. In short, for those that wish to invest themselves into Making Their Own Stuff, it is now possible in ways not possible before. Still, it does require an investment of self to succeed.

Example: mcHF, started by Chris, m0nka, in the UK, and supported by a cast of others. They’ve designed a small, SDR centric HF rig that you can build if you’re willing to invest yourself a little. The design is released under non-commercial usage constraints, and PCBs are available for nominal cost. In short, it’s a reasonable way to get exposed into the current state-of-the-art in “smart” radio technology.

I’ve been watching the project for several months now, and finally decided to dive in, with 2 pairs of boards (one pair for a working radio, one to hack on), arrived yesterday:

mcHF RF and UI Boards

Design-wise, this is the kind of project that, if I had the time, I’d love to have undertaken myself. On the other hand, my engineering background is more software and systems with a little RTL thrown in; even though I understand how the hardware works, I’m not sure I’m up to designing one from scratch with this technology. Troubleshooting/modifying/improving it, however, may help me learn enough to cross that design threshold. Besides, it looks like fun.

What’s compelling about mcHF is that it’s an SDR design; that is to say that the modulation/demodulation/filtering (all the “magic” radio stuff) is done in software instead of captive hardware. This does two things; it reduces the cost and complexity, while enabling changes or improvements in functionality without requiring hardware redesign.

(Ironically, I spend a lot of my professional time with software, and I dabble in this space because I want the distraction of playing with hardware, not software. Go figure…)

I suspect that the future of HF operating is really in digital modes; the really interesting and useful future things will happen in digital, and this is just the kind of open platform to make hacking in this space possible.

So, I’ll try to work on one (actually two). Watch this space…

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s