Found in a 90s Popular Electronics, this circuit allows to select the operating ranges between short waves and VHF. MOSFET is uncommon today.
This flip-flop with neon lamps was found in a 1969 publication that deals precisely with neon...
This simple circuit applies to any sensitive SCR. We found it in 1982 Maplin documentation. ...
Found in American documentation from the 1990s, this circuit causes the fuse to blow in the event...