Found in 1965 Delco Radio documentation, this circuit uses transistors from that era. Modern equivalents can be used. The characteristics of the inductor were not given.
This buzzer with the 555 was suggested by a Popular Electronics from the 90s to be used as a...
This is the receiver for the previous circuit found in the November 1991 Radio Electronics...
In the figure we have the configuration of series regulator protector suggested by Motorola in 1968...