This circuit is from a 1980's documentation for telecommunications. The circuit is used in SSB and the diodes must be suitable types for the application. The audio input is low impedance.
This 8-channel converter was found in a 1970s American documentation. The integrated circuits used are...
We find the original version of this circuit in an English publication (1986). It is a...
This experimental telegraphic communication system can have wires connecting to the handset of...