This circuit consists of an improved version of the CIR5892, using two transistors and adjusting the operating point. The transistors can be the BC548.
The circuit is simple, as it uses only one transistor and a relay that can be MC2RC1 or MC2RC2,...
We found this circuit in a 1990 documentation. It works with the power of the digital circuit...
The filter shown in the figure can operate with frequencies up to several tens of megahertz thanks...