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.
We found this circuit in a 1998 publication. The circuit has controls for both frequency and...
This circuit for conventional lines was obtained in a 1996 documentation. The circuit uses common...
This is the conventional version of capacitance multiplier with operational amplifier that appears in...