This filter was found in an old publication from 1977. The circuit must use a simple two-voltage source and the components can be changed for operation at other frequencies.
This is a Japanese commercial radio from the 60s. The circuit is listened to by phone and is...
The first circuit we present is ideal for matching the low impedance of transducers, such as...
We found this circuit in Motorola's Linear Databook in 1990. The component used is not common today....