This circuit with TTL output was found in a 1968 EEE. The transistor can be of general use. The tunnel diode is an uncommon component today.
We found this circuit in a documentation for 1977 American radio amateurs. The LM336 integrated circuit...
The frequency of this oscillator depends on the coil and the 10 nF capacitor. The circuit is from...
This circuit can work with the previous one generating signals, that can be decoded by it. The...