| Part | Total Qty. | Description |
| R1 | 1 | 470 Ohm 1/4 Watt Resistor |
| R2 | 1 | 1K 1/4 Watt Resistor |
| R3 | 1 | 100K 1/4 Watt Resistor |
| R4 | 1 | 6K 1/4 Watt Resistor |
| C1, C2 | 2 | 0.01 uF 100V Ceramic Capacitor |
| K1 | 1 | 24VDC Reed Relay |
| MISC | 1 | Wire, Headphone Plugs, Phone Plug Or Alligator Clips |
Note:
- To use the circuit, simply connect it in series to the phone. Then plug in the recorder. It will start recording when the phone is picked up.
- The values of R1 and R2 may have to be adjusted, depending on the characteristics of the phone line it is connected to (they vary). If the R1+R2 combination is increased sufficiently (try 2.47K) then the circuit can be connected in parallel with the line, thus covering all attached devices.
- If you drop the resistors and add a 2.2uF capacitor the line will not stay off hook. It blocks the DC from the moniter position.
