This circuit from a June 1957 Radio Electgronics is for oscilloscopes of the time with a maximum frequency of a few megahertz. The circuit is battery powered.
Placed near a telegraphic transmitter (CW) and with a small antenna or pickup, it reproduces the...
The LM387 integrated circuit used in this project is not very easy to obtain. The circuit, from an...
The recommended distance between the emitter and the sensor of this coupler is 15 mm. The circuit is...