This is a basic inverter circuit for a 70 kHz crystal. We found it in an old documentation using an operational of the time.
This circuit was found in Motorola's 1968 documentation. It can be built on current equivalent...
I found this circuit in an English magazine from 1977, but the circuit can be easily assembled by the...
The circuit shown is only for analog telephone lines. I found it in Popular Electronics (1991). It...