Found in Motorola documentation from the 1970s, the circuit presented uses a component from the era that is not common today. The characteristics of the coils are given next to the diagram.
We found this circuit in an old publication for radio amateurs from 1975. It is intended for...
This generator is more complete than the previous one, being able to generate pulses as indicated...
This tone control was obtained in the Audio Handbook of the National Semiconductor of 1977. The...