Some construction projects, presented mostly for information and inspiration, not as building instructions:

• Receiving 10 Mbit/s ethernet frames on a bare AVR microcontroller using "bit-banging". (2014)
• My SDR (Software Defined Radio) developments between 2004 and 2009.
• My neon clock: a clock which uses neon bulbs as logic elements and nixie tubes for display. It contains no transistors or integrated circuits! (2007)
• Simple and better circuit for MiniWhip antennas, as used in the Twente WebSDR. (2017)
• My second neon clock: a clock which uses trigger tubes as logic elements and nixie tubes for display. It contains no transistors or integrated circuits! (2020)
• Ultra-low power continuity tester. (2021)