This circuit was found in an American publication in 1966. The circuit uses a general-purpose FET that admits an equivalent. The instrument is a 250 uA full-scale microammeter.
The configuration shown in the figure is a second order filter (12 dB per octave) with an...
This transmitter, indicated for espionage applications, is permanently powered by the power grid....
This circuit was obtained in an old French publication from the 80s. The maximum power of the lamp...