We found this circuit in a 90s Radio Electronics. The circuit generates frequency-modulated 220 kHz signals. The components used are still common.
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...