Found in an April 1977 Radio Electronics issue, this circuit uses the well-known XR2206. The C1 values for the various frequency bands are given next to the diagram.
This circuit is from Radio Electronics from March 1977. The integrated circuit is from that time...
This 1.2 to 32 V x 3 A regulator was found in an 80's EDN. The power components must be equipped...
This power control from Motorola's 1971 SCR Power Control Fudamentals can control full wave loads...