We found this circuit in Ferranti's 1974 transistor manual. The components are from the period. The table gives the value of C1 for different frequency ranges.
In the figure we have a simple signal tracer circuit to be coupled to the volume control of an AM...
This circuit was found in documentation from the 90s, using components from that time. The...
This circuit, obtained from old documentation, allows the recovery of sulfated batteries. The...