MIT Extracts Power from Temperature Fluctuations

As a civilization, we are proficient with the “boil water, make steam” method of turning various heat sources into power we feed our infrastructure. Away from that, we can use solar panels. But what if direct sunlight is not available either? A team at MIT demonstrated how to extract power from daily temperature swings.

Running on temperature difference between day and night is arguably a very indirect form of solar energy. It could work in shaded areas where solar panels would not. But lacking a time machine, or an equally improbable portal to the other side of the planet, how …read more

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Vintage Transistor powers QRP Transmitter

[Pete Juliano, N6QW] built a 20 M QRP CW transmitter using just a handful of parts. That in itself will not raise any eyebrows, until you find that he built it using one of the very first RF transistors manufactured all the way back in 1955. That’s from before the time most of us were born and not many years after the invention of the transistor in late 1947.

QRP in HAM-speak technically stands for a request to “reduce power” or an offer of “should I reduce power” when appended with a question mark. A QRP transmitter is designed to …read more

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