Red Box PhreaksGreetings!
On the single-slot coin phones I have frequently been able to get a dial tone by putting in a nickel and giving the hookswitch a short tap (this takes practice). The dial won't work, though, so you will have to tap out 211 to get the operator.
I have built a red box using an oscillator, a telephone earpiece, and an AE phone dial. The shorting contacts of the dial are used to turn on the oscillator when the dial is off normal, and the break contacts are used to short out the output of the oscillator except during the tone pulses. Nickel, dime, and quarter sounds are made by dialing 1, 2, and 5 respectively. (although #6 seems to sound better as a quarter).
On my phone line whenever you dial a toll call
(including 800 and info), the polarity of the line is
reversed for about a second. If a diode is wired into the
line so that it conducts only when the polarity is normal,
the phone will be electrically hung up whenever a long
distance call is made & can be used like a "dial-lock"
but this device is foolproof (but only for long distance).
ED. NOTE: For those of you who want to make a simple and reliable red box, we show a schematic of an oscillator and amplifier and telephone dial. It is basically the same as last month's red box, except that a telephone dial replaces the flip-flop and timer, thus mechanically producing the tones. All resistors are half watt 10%. Transistor is 2N2222, SK3020 or Hep 54. 30K trimmer is used to adjust frequencies to match that of a pay phone. Remember, pay phone tones are best heard on another phone that has called the pay phone. When listening to an actual pay phone, keep in mind that a quarter produces faster beeps than a nickel or dime. Adjust the speed of the dial to produce accurate nickels or dimes. Then simply force dial to return faster for the quarter (it takes a little practice). If you don't know how to adjust the speed of the dial here's how it's done: on the back of the dial is a governor which looks like a disc brake. The semi-circular brake shoes slow down the dial when not held in tightly by the spring. Tighten the spring for faster dial return. This is tricky on the enclosed governors, but it can be done.
Our Red Box circuit of last month isn't perfect, and we've got a few improvements. First, change the value of the 2.2K flip-flop resistors to 10K ohms. This will cut down your battery drain to less than 4 milliamps. Secondly, if you're getting strange extra pulses when you continue holding a button down, try putting a 25 mfd. capacitor right across the battery. Finally, if you experience incomplete turn-on or turn-off of the tones, change the 22K timer output resistor to 47K. If you want to build a red box but don't know how, YIPL will publish next month instructions for recording the tones perfectly on a cassette tape recorder. Any inexpensive unit will work, but it's easiest to use a cassette with manual recording level controls.
Red Box Phreaks