This nifty little circuit lets you record your phone conversations automatically. The device connects to the phone line, your tape recorder’s microphone input, and the recorder’s remote control jack. It senses the voltage in the phone line and begins recording when the line drops to 5 volts or less. R1 1 270K 1/4 W Resistor R2 1.5K 1/4 W Resistor R3 68K 1/4 W Resistor R4 33K 1/4 W Resistor C1 0.22uF 150 Volt Capacitor Q1, Q2 2N4954 NPN Transistor D1 1N645 Diode MISC Wire, Plugs To Match Jacks On Recorder, Board, Phone Plug.
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