225 lines
11 KiB
Plaintext
225 lines
11 KiB
Plaintext
BUILDING A RED BOX
|
|
by JR "Bob" Dobbs
|
|
|
|
Essentially,the red box is a device used to fool the phone company into thinking
|
|
you are depositing coins into a payphone. Every time you drop a coin into a
|
|
payphone, the phone signals the type of coin inserted with one or more bursts of
|
|
a combination of 1700hz and 2200hz. The tone bursts are coded as follows:
|
|
Nickel:One 60 millisecond pulse
|
|
Dime :Two 60 millisecond pulses separated by 60 milliseconds
|
|
Quarter:Five 35 millisecond pulses separated by 35 milliseconds
|
|
|
|
HOW TO USE IT
|
|
-------------
|
|
Operation is simple. Simply dial a long distance number (some areas require you
|
|
to stick in a genuine nickel first), wait for the ACTS computer to demand your
|
|
cash, and press the "deposit" button on the red box for each coin you want to
|
|
simulate. The coin signals are coupled from the red box into the phone with a
|
|
small speaker held to the mouthpiece. For local calls, either you must first
|
|
deposit a genuine nickel before "simulating" more coins or place your call
|
|
through the operator with 0 + 7d. Use some care when the operator is on the
|
|
line--sometimes they catch on to your beeper ploy.
|
|
|
|
CIRCUIT OPERATION
|
|
-----------------
|
|
Each time the pushbutton is pressed, it triggers half of IC1, configured as a
|
|
monostable multivibrator to energize the rest of the circuit for a length of
|
|
time determined by the setting of the coin selector switch. This in turn starts
|
|
the other half of IC1, configured as an astable multivibrator, pulsing on and
|
|
off at regular intervals at a rate determined by the 50k pot between pins 12 and
|
|
13. The output of the astable thus alternately powers of IC2, configured as a
|
|
square wave oscillator, providing the required 1700hz and 2200hz to the op amp
|
|
which acts as a buffer to drive the speaker.
|
|
|
|
CONSTRUCTION
|
|
------------
|
|
Assemble the circuit as you wish. Component placement is not critical. I found
|
|
the easiest method was to use point-to-point wiring on a "universal" PC grid
|
|
board with solder ringed holes. Use sockets if you aren't a whiz with a
|
|
soldering iron. Be sure to leave easy access to the potentiometers for alignment
|
|
|
|
ALIGNMENT AND TESTING
|
|
---------------------
|
|
For alignment, a frequency counter and tiggered sweep oscilloscope are extremely
|
|
handy (but not absolutely necessary.) Install a temporary jumper from +9v
|
|
supply to pin 14 of IC2 and temporarily disconnect the 0.01uF capacitors from
|
|
pins 5 and 9 of IC2. Power up the circuit. Measuring the output from pin 5 of
|
|
IC2 with the frequency counter, adjust the 20k pot between pins 1 and 6 for an
|
|
output of 1700hz. Now adjust the 20k pot between pins 8 and 13 for an output of
|
|
2200hz from pin 9 of IC2. Remove the temporary jumper and re-attach the
|
|
capacitors to pins 5 and 9. (Note: if no frequency counter is available, the
|
|
outputs can be adjusted by ear one at a time by zero-beating the output tone
|
|
with a computer generated tone of known precision.) Next, temporarily disconnect
|
|
the wire between pins 5 and 10 of IC1. Set coin selector switch in the "N"
|
|
(nickel) position. With the oscilloscope measuring the output from pin 9 of IC1,
|
|
adjust the 50k pot between pins 12 and 13 of IC1 for output pulses of 60
|
|
millisecond duration. Reconnect the wire between pins 5 and 10. (Note: If no
|
|
scope is available, adjust the pulse rate by ear using computer generated tones
|
|
for comparison.) The remaining adjustments are made by ear. Leave the selector
|
|
switch in the "N" position. Adjust the 50k pot labelled "Dime" for a quick
|
|
double beep each time the pushbutton is pressed. Finally, set the selector to
|
|
"Quarter". Adjust the 50k pot labelled "Quarter" until exactly 5 very quick
|
|
beeps are heard for each button press. Don't worry if the quarter beeps sound
|
|
shorter and faster than the nickel and dime ones. They should be.
|
|
|
|
CONCLUSION
|
|
----------
|
|
If all went well to this point, your red box should be completely aligned and
|
|
functional. A final test should now be conducted from a payphone using the DATL
|
|
(dial access test line) coin test. Dial 09591230 and follow the computer
|
|
instructions using the red box at the proper prompts. The computer should
|
|
correctly identify all coins "simulated" and flag any anomalies. With a little
|
|
discretion, your red box should bring you many years of use. Remember, there's
|
|
no such thing as spare change.!
|
|
|
|
Parts list for Red Box
|
|
----------------------
|
|
Semiconductors
|
|
--------------
|
|
(2)556 dual timer
|
|
(1)741 Op Amp
|
|
(1)1N914 Switching Diode
|
|
|
|
Resistors
|
|
---------
|
|
(6)10k
|
|
(1)4.7k
|
|
(2)100k
|
|
(4)50k PC Mount Potentiometer
|
|
(2)20k Multi-Turn Potentiometer
|
|
|
|
Capacitors
|
|
----------
|
|
(10)0.01uF
|
|
(1)1.0uF
|
|
(2)10.0uF Electrolytic
|
|
|
|
Miscellaneous
|
|
-------------
|
|
(2)14 Pin Dip Socket
|
|
(1)8 Pin Dip Socket
|
|
(1)3-position Rotary Switch
|
|
(1)Momentary Push-Button Switch(normally open)
|
|
(1)SPST Toggle Switch
|
|
(1)Speaker or Telephone Earpiece Circuit Board
|
|
(1) Box
|
|
(1) 9v Battery Clip Mounting Hardware
|
|
|
|
SCHEMATIC DRAWING
|
|
-----------------
|
|
|
|
/ ÚÄÄS1ÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄ¿
|
|
+9v R1 R2 ³ ³ ³ ³
|
|
ÃÄÄÄC1ÄÄÄÄ´ ³ R3 ³ ³
|
|
³ ³ ÚÄÄÄ´ ÃÄÄÄÄÂÄC2Ä@q S3 @n ³
|
|
o ÚÄÄÄÁÄÄÄÄÁÄÄÄÁÄÄÄ¿ ³ R5 ³ @d ³ ³
|
|
oÄ´ ³ 6 4 14 ³ R4 ³ ³ ³ ÃÄÄ¿ ³
|
|
S2 o ÚÄ´5 13ÃÄÄÄÄ´ g ³ ÃÄÄÄ¿ ³ ³ ³
|
|
³ ³ ³ ³ ³ ³ ³ ³ R9<ÄÙ ³
|
|
g ÀÄ´10 (IC1556) 8ÃÄ¿ R6<Ä¿ ³ R8<ÄÄÙ ³ ³
|
|
³ ³ ³ ³ ³ ³ ³ ³ ³
|
|
ÚÄÄÄÄ´9 12ÃÄÁÄÄÅÄÄÙ ÃÄÄ¿ ³ ³ ³
|
|
³ ³ 3 11 7 2 1 ³ C3 ³ ³ ³ ³ ³
|
|
³ ÀÄÂÄÄÂÄÄÄÂÄÄÂÄÄÂÄÙ ³ R7<ÄÙ ³ ³ ³
|
|
³ ³ ³ ³ ÀÄÄ´ g ³ ³ ³ ³
|
|
³ C4 C5 ³ ÃÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÁÄÄÄÄÄÄÄÙ ³
|
|
³ ³ ³ ³ C6 ³
|
|
³ ³ ³ ³ ³ ³
|
|
³ g g g g ³
|
|
³ ³
|
|
ÀÄÄÂÄÄÄÄÄÂÄÄÄÄÄÄÄ¿ ³
|
|
R11 ³ R12 ÚÄÄÄ¿ ³
|
|
ÚÄÄ¿ ³ ³ ³ ³ v ³
|
|
v ³ ³ ÚÄÄÅÄÄ¿ ÃÄÄÄÄÁÄÄR13ÄÄ¿ ³
|
|
ÚÄÄÄR10ÄÁÄÄ´ ³ ³ ³ ³ ³ ³
|
|
³ ÚÄÁÄÄÁÄÄÁÄÄÁÄÄÄÄÁÄÄÄÄ¿ ³ ³
|
|
³ ³ 1 4 14 10 13 ³ ³ ³
|
|
³ ³ 8ÃÄÄÂÄÄÄÄ´ ³
|
|
ÃÄÄÄÄÄÄÂÄ´6 ³ ³ C12 ³
|
|
³ ³ ³ 12ÃÄÄÙ ³ ³
|
|
³ ÀÄ´2 IC2 556 ³ ³ ³
|
|
C7 ³ ³ g ³
|
|
³ ÚÄÄ´3 11ÃÄÄÄÄÄ¿ ³
|
|
³ ³ ³ 7 5 9 ³ ³ ³
|
|
g C8 ÀÄÄÄÄÂÄÄÄÂÄÄÄÂÄÄÄÄÄÄÄÙ C11 ³
|
|
³ ³ C9 C10 ³ ³
|
|
³ ³ ³ ³ g ³
|
|
g ³ ÀÄÂÄÙ ³
|
|
g ³ ³
|
|
³ ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ
|
|
³ ³ ³
|
|
³ R14 ³
|
|
³ ³ ³\ ³
|
|
³ ³ ³ \ ³
|
|
ÃÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄij3 \³
|
|
³ ³ ³ 7 \
|
|
C13 R15 ³IC3 \
|
|
³ ³ ³741 6/ÄÄÄÄÄÄ¿
|
|
³ ³ ³ 4 / ³
|
|
³ ³ ³ / ³
|
|
g g ÚÄÄ´2 / ³ ³
|
|
³ ³/ ³ ³
|
|
³ g ³
|
|
ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ´
|
|
C14
|
|
³
|
|
Speaker
|
|
³
|
|
g
|
|
|
|
Schematic part variables list.
|
|
------------------------------
|
|
Resistors
|
|
---------
|
|
R1 - 10k
|
|
R2 - 10k
|
|
R3 - 4.7k
|
|
R4 - 10k
|
|
R5 - 10k
|
|
R6 - 50k
|
|
R7 - 50k
|
|
R8 - 50k
|
|
R9 - 50k
|
|
R10- 20k
|
|
R11- 10k
|
|
R12- 10k
|
|
R13- 20k
|
|
R14-100k
|
|
R15-100k
|
|
|
|
Capacitors
|
|
----------
|
|
C1 - 0.01uf
|
|
C2 - 1N914 switching Diode
|
|
C3 - 1.0uf
|
|
C4 - 0.01uf
|
|
C5 - 0.01uf
|
|
C6 - 10uf
|
|
C7 - 0.01uf
|
|
C8 - 0.01uf
|
|
C9 - 0.01uf
|
|
C10 - 0.01uf
|
|
C11 - 0.01uf
|
|
C12 - 0.01uf
|
|
C13 - 0.01uf
|
|
C14 - 10uf
|
|
|
|
Switches
|
|
--------
|
|
S1 - SPST toggle
|
|
S2 - Momentary push button N.O. labeled "Deposit"
|
|
S3 - 3-position rotary switch
|
|
|
|
Miscellaneous
|
|
-------------
|
|
g - Ground @q -
|
|
Label "quarter" @d -
|
|
Label "dime" @n -
|
|
Label "nickel"
|
|
|
|
Typed up by Sine Wave from an article which originally appeared in 2600 magazine.
|
|
The original contained several mistakes in the schematic drawing which I've
|
|
corrected. Hope this information enlightens you to new and exciting possibilities
|
|
via your local phone booth.
|
|
|