This circuit is from 1964 documentation but can be easily implemented based on current components. Input waveforms and detection are shown next to the diagram.
We found this circuit in an American documentation of the 80's, being indicated for the test of...
The circuit shown is a documentation on 80's tunnel diodes. The frequency depends on the delay line...
This shield can be used both to interface microcontroller circuits or TTTL. The resistor in series...