This circuit uses components of the time. We found it in a 1968 US documentation. The delay is 100 ns and the input impedance is 1 k.
This circuit was found in an Electronics Now from the 80's. The frequency depends on the...
We found this traditional configuration in an Italian 1960 documentation. The transistor can be...
This receiver was found in an article in Electronics Now magazine in March 1994. The coils are...