100 mA regulator (CB21168E)

This 2-terminal regulator was obtained from a 1990s National Semiconductor manual. The components admit modern equivalents.

fet infrared Modulator (CB14681E)
The circuit shown is from the Texas Instruments optoelectronics manual, applying to low power...
High Impedance 2 W Amplifier (CB6163E)
This circuit was found in a 1968 General Electric documentation. It has an input impedance of 2 M ohms...
Twin-T Rejector Filter 741 (CB25603E)
This filter that rejects a frequency range determined by the double-T was found in the August 1993...