In the figure we have the way to control a flip-flop with the 4069 from positive pulses. The circuit can be used as a shield, if powered by 5 V.
Found in a publication for radio amateurs from the 1990s, this circuit makes it possible to...
I found this circuit in a Popular Electronics from November 1999. The magazine is no longer...
This simple transistorized receiver with earphone was found in a Japanese publication from the...