Found in an American documentation, this circuit shows how an interface should be made for recording telephone conversations with quality and safety.
Based on the Linear Technology LTC2054, this -48 V circuit was found in a 2005 manual. The circuit is...
The circuit uses a fast Norton amplifier in a configuration that excites a 75 ohms line. The...
Found in a Popular Electronics from the 1990s, this circuit uses components from National...