This circuit automatically records all incoming and outgoing phone conversations with an ordinary cassette or tape recorder. The circuit below distills the audio signal from the phone line and automatically starts/stops the cassette recorder. [...]

This circuit allows you to construct a electronic switch which will automatically turn on your tape recorder when you pick up the handset of your telephone.So that your tape recorder must have both a MIC socket and a REMOTE socket on it so that circuit can plug into the recorder and control it.This circuit will allow you to record both sides of your telephone conversations. [...]