This circuit was found in a publication by Edelman from 1924. The power comes from the battery and the listening is through a high-impedance headphone.
This circuit allows the listening of undersea sounds using a special transducer. Operational...
The presented circuit uses an operational one of the time. The circuit is from an 80's manual and...
This circuit can be found in all 723 manufacturer's manuals. This circuit is specifically from...