First of all, the tones made by a touch tone telephone are not single tones, they are a combination of two tones, making "DTMF" (dual tone multi-frequency). The normal tone telephone dials 12 different signals, but is capable of dialing 16 different signals (see bulletin on silver boxes).
The power required by a keypad is about 25 volts, but they will work with as little as 15, thereby allowing the use of two 9- volt radio batteries. As you may have guessed, they are also designed to operate with a telephone type speaker (and phone line), and not the standard 8-ohm speaker which needs to be used for adequate volume. To accompolish this, we use a matching transformer, this is one of those miniature ones available at Radio Shack. Enough of the theory, now for the circuit.
You will need:
First, connect the RED wire of the transformer to either terminal on the speaker. Now connect the WHITE wire from the transformer to the other terminal on the speaker. Next, connect the RED (positive) wire of one battery clip to the black wire of the other battery clip. Now connect the the remaining RED wire on the second battery clip to the GREEN wire from the touch tone pad. Connect the BLUE wire from the touch tone pad to the ORANGE-and-BLACK striped wire from the touch tone pad. To these two wires, now connect the remaining black lead from first battery clip. You have now finished the power connection to the keypad. Connect the BLACK wire from the keypad to the BLUE wire on the transformer. Next connect the RED-and-GREEN striped wire from the keypad to the GREEN wire on the transformer. The BLACK wire on the transformer should not be connected to anything, along with quite a few wires from the keypad. The connection of the keypad is now complete. All you have to do is connect two nine volt batteries to the battery clips, and you'll be ready to go. You may want to mount it in a case for easy portability. Note that the silver box modification CAN be made to this unit, allowing complete remote phreaking. When none of the buttons are pressed, this unit uses NO power, thereby eliminating the need for a power switch, and extending the life of the batteries.
The following are the frequency combinations generated by each button on the keypad.
KEY FREQ. #1 FREQ. #2 --- -------- -------- 1 697 1209 2 697 1336 3 697 1477 A 697 1633 4 770 1209 5 770 1336 6 770 1477 B 770 1633 7 852 1209 8 852 1336 9 852 1477 C 852 1633 * 941 1209 0 941 1336 # 941 1477 D 941 1633All frequencies are measured in Hertz Note that A,B,C and D are not normally present (except for silver boxes)