We found this circuit in the 1990 Philips Databook. The circuit is a commercial application of the decoder in stereo FM radio receivers.
We found this interesting configuration in a 1976 technical documentation. Equivalent diodes can...
This circuit can generate signals of different frequencies, switched by a DC voltage. The...
This circuit, from a publication from the 1970s, can be implemented with more modern transistors and 6 or...