This notch filter was found in National Semiconductor documentation from the 1980s. Operational amplifiers are from that era. The configuration can be adapted to use modern operational amplifiers.
This QST circuit generates 4 frequency signals according to the crystals used. Transistors admit...
This countdown electromagnetic ring launcher was found in an Electronic Hobbyst Handbook from...
This TTL circuit was found in an American documentation from the 80s. The components are common in the...