This filter was found in a Texas Instruments manual based on an operational amplifier 741. Other operational can be used and, with the indicated components, the rejection frequency is 2 kHz.
This circuit is from a 1976 Motorola CMOS manual. It can be implemented with modern Darlingtons like...
The circuit presented is from a 1972 RCA technical documentation. The integrated circuit consists of a...
We found this transmitter circuit for different frequency ranges in a 1992 documentation. The...