Found in old documentation, this receiver for the mid-wave range uses transistors from the era. In fact, modern general-purpose equivalents can be used.
This circuit can generate 10 MHz signals depending on the crystal and has excellent stability....
This TTL digital circuit from Texas Instruments documentation from the 1970s used the company's SN types...
We found this simple transistor tester in a French publication in 1981. It uses a common analog...