I build radios and things to support them — mostly open-source, mostly for the joy of getting something to work. This is where I keep notes on what’s on the bench, in the hope that some of it saves you an afternoon or the whole project.
I like things you can hold: a receiver that pulls signals out of the air, a board that turns USB into light, a clock steady enough to trust. I also like to save a bit of money, where a good hack can do, we do!
Some of it is finished, most of it is in progress, and a fair bit fought back before it behaved. I explain it like a friend at the workbench — plainly, and without pretending it was easy.
If you’d rather jump straight in: the RX888 mk2 SDR stack is the most complete thing here, and the notebook has the running account of everything else.
Fresh ink in the notebook
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The Si5351 clock generator that disappeared…
I’d been getting the RX888 firmware ready for people to actually lean on, which, right before you hand a thing to users, means trying to break...
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The RX888, end to end
There’s a particular kind of satisfaction in watching a signal travel the whole length of something you built. This week the RX888 mk2 did exactly that...
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A loop, a stepper, and a Tuesday night
This is a CLASSIC post from work I did 6 years ago with my friends at Len Long’s Tuesday Night Workshop. Len W1ZTL my eternal thanks...
What’s on the bench
The RX888 mk2 SDR stack
An open-source software stack for the RX888 mk2 direct-sampling HF receiver:
Cypress FX3 firmware, the librx888 host library and CLI tools, and a
GNU Radio 3.10 source block. Three MIT-licensed repos that turn the raw
hardware into a receiver you can actually use on Linux.
USB3-to-fiber link
A KiCad 10 board that carries USB 3.0 over optical fiber — for getting a noisy computer far away from the reciever and a quiet antenna without dragging the hash along with it.
Precision timing bench
Scripts and plots for standing up a precision time-and-frequency workbench — disciplining a reference, measuring how far off it is, and drawing the picture that tells you.
Loop rotator & tuner
Arduino firmware for a motor-driven magnetic loop antenna — rotate it, tune it, and stop fiddling with the capacitor by hand. Born at W1ZTL’s Tuesday Night Workshop.
More on GitHub
EM simulation with openEMS, IMU magnetometer calibration, a FIT-file ride analyzer, and the usual drift of small experiments. Have a poke around.
I’m glad you stopped by. Pull up a stool.