With an 18 V input, this regulator was found in Philips documentation from the 60's. The transistors are from that time. The power transistor must have a heatsink.
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...