This circuit is from an English documentation from 1969. The circuit can be designed based on modern equivalent transistors. Diodes are general purpose types.
This fast trigger circuit allows the counting of up to 300 pulses per minute. The circuit is from...
This intercom uses transistors from the 60s. It was found in a Japanese publication at the time....
This circuit is from an old publication from the 90s, but it can be adapted to operate with LEDs....