We’ve been loving the variety of entries to the 2025 One-Hertz Challenge. Many a clock has been entered, to be sure, but also some projects that step well outside simple timekeeping. Case in point, ...

A crystal radio is a common enough science fair project, but the problem is, there isn’t much on anymore. The answer is, of course, obvious: build your own AM transmitter, too. AM modulation isn’t ...

The AM transmitter can be used near an AM radio that is tuned to 1000 in order to hear the sound source from the user in the AM radio or send voice and music across the room or street. The heart of ...

If a crystal radio is the distilled essence of a radio, this transmitter is the matching distilled essence of transmitters. The transmitter goes together in about 10 minutes, and is small enough to ...