4093 Sine Square Converter (CB26335E)

Found in a Popular Electronics from the 90s, this circuit operates up to about 5 MHz input.

Transformer Audio Output Stage (CB18304E)
This circuit with only one transistor was found in Japanese documentation from the 1960s. The...
Beta Meter (CB3804E)
This circuit uses a common multimeter on the voltage scale. The calibration of the scale should be...
CPU Interface ADC0801 to 0804 (CB15351E)
This interface shield circuit is from the 1983 Intersil Databook. The components used are uncommon...