This oscillator with emitter follower was found in an American documentation from the 80's. The circuit generates 100 MHz signals and the transistors admit modern equivalents.
This negative ion generator was found in a 90s Popular Electronics. The autotransformer can be an...
This circuit of the 80s makes use of an operational one of the time. It can be designed with...
This timer activates a relay after a time interval of up to 15 minutes has elapsed, starting from...