In the figure we have 3 oscillators with logic gates that can be triggered by external logic signals. The circuits were found in the Radio Electronics magazine of April 1987.
This transmitter operates in the FM band emitting beeps that can be picked up on a common radio at...
This configuration can be found in other articles on this site. This was obtained in 1998...
This circuit is from a documentation from the 70s. Thus, the original transistor no longer exists,...