This circuit is valid for other comparators of the same series. In this case, a lamp is excited, but an LED can be used in series with a resistor or other load. The transistor admits equivalent.
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...