Found in Popular Electronics from the 90s, this circuit generates signals in a frequency range set to R7 and basically determined by C1. Operational and equivalent transistors can be used.
Found in a magazine 73 for radio amateurs, in a 90's edition, this circuit uses a general-purpose FET...
The selected circuit causes a 12 V lamp with a current of up to 500 mA for the BD135 transistor to flash at...
This is one of the many applications of the 555. We found it in the November 1992 Radio...