This untuned (aperiodic) amplifier circuit was found in the August 1974 Radio Electronics magazine. The transistors are period, and the board layout is critical.
For those who like experimental circuits, here is a sequential flasher system with LEDs, which can be...
This circuit was found in an ancient American documentation. The integrated circuit is of the time...
This circuit was found in a 1977 Radio Shack documentation. The circuit is tuned to 1.4 kHz, but...