Introduction: The Radio Project

I’ve had a general-class amateur radio license for a while and I’ve never really used it too much. Now I’m in a better (physical) place where I can experiment so I’m embarking on a new project.

What Changed & What Didn’t

First and foremost, I have space. Previously I was limited to what I could wire up in an apartment. Antennas can get dangerous and between visitors and the cat there was too much work preventing RF burns, tripping over things and just plain ugly.

Also along the lines of space, I have space to experiment. I made a promise of limiting, “dirty,” work like greasy truck parts and that which generates milled metal dust. Electronics work is, “clean,” in that keeping your breadboard neat is a good habit and no one (who I’m likely to have around) can see in the RF spectrum. I’ve got space for tools, leaving projects unfinished and testing away from the cat.

Still on that track, I don’t have many external restrictions. There’s space to put up antenna masts and I can punch holes through walls for feeders to my heart’s content.

On the negative side, I’m now mired in what’s likely to be ten years’ worth of construction projects. It could all probably be done in two years but I’m expanding the schedule to accommodate work, budget and interesting projects. Before I may have been able to find an hour a day to work on this. Now it’s more likely an hour a week over the stretch.

The place I moved into came with lots of materials as well. I’ve got a functionally unlimited supply of some things (sand, glass and aluminum) and good supplies of other things (steel, rocks, electrical wattage). Further, time spent looking will afford the ability to get lots of used and transcyclable parts from scrapped fixtures like cars, electronics and machinery.

Goals

Fast, cheap and good… pick two. I’m picking cheap and good. Those constraints truly limit just about every choice in the project. Along those lines, most of the choices are for either common parts (like feeder cable) and focus on taking the time to build something that may be difficult (like matching circuits).

I’d like to be able to cover several frequency bands with three or fewer antennas. My intuition says I’ll need one good VHF/UHF antenna, a good HF antenna and something that’ll do well on some lower frequencies (I’d like to experiment with MF and LF or even ULF/VLF based on regulation and availability). I’d like to be able to transmit using reasonable power levels. “Reasonable,” here definitely means within regulation but also what can be attained using reasonable parts. High-power transmission is expensive.

Where possible I want to transcycle as much as possible. I assume this means I’ll be reworking quite a number of component parts as I come up with new ideas. This also means that I’m probably going to have to develop (build or buy) solid tooling and measurement for a great many things. I’m an electrical engineer — not a mechanical engineer — so I’ll probably do more guestimation on weight bearing or wind profiling and build better systems to measure things like VSWR and connector loss.

Personal interest will play into everything. I really don’t care much about the history of the Yagi-Uda antenna. Lowering reactive loss per foot of coax and impedance matching is interesting to me. This probably isn’t the same for everyone but it’s my project.

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