This balance or balance circuit with phase inversion was found in documentation from the 90s. Transistors can be low noise equivalents like BC549.
Found in a PE Hobbyst Handbook, this circuit checks if there is voltage in a power outlet by...
This circuit was found in an article in Electronics Now magazine from June 1998. The sensor...
This circuit generates an FM signal of 4.7 or 10.7 MHz for audio signals on analog TV or FM, with...