This circuit uses an MW radio tuned to around 540 kHz to detect atmospheric signals, for example, from an approaching storm. The circuit was taken from a Popular Electronics from the 90s.
November 2016 - Texas Instruments' new TLV8802 nano-power operational amplifiers for wireless...
This sophisticated photometer that has a light comparator with LED indicator came out in an...
This is a version of the previous circuit that includes a tone modulator based on a Hartley...