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.
Common operational amplifiers like the TL series, CA3140 and others can be used in this circuit...
This high-gain amplifier was found in the March 1994 issue of Electronics Now magazine. The...
We found this timer for times of a few minutes in a 1974 Ferranti transistor manual. The relay is 37...