This assembly is from 1957 from a Raytheon manual, but can be modernized using a BC548, 6 V power supply and common 100 mA relays.
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...