                          PRIVATE PAYPHONES #3


Hello, once again here I am to talk about Phreaking Private Payphones.
Lesson Three: Other Phrauding Methods.  One of the notable things about
private payphones is that they have to detect signals from the phone line
(like busy, ringing, etc.) to determine the path your bucks will take
when you hang up, into the cashbox (burp), or the coin return (ching!).
One of the signals in particular the phone is looking for is the 3 musical
tones you get for an intercept recording.  (You know, BEEP-BEEP-BEEP, the
number you have reached is screwed... etc.)  Record these tones with a pocket
tape recorder, or what have you and play them 1-2 seconds after the phone
connects you to whoever.  One of two things will happen:  The phone will sub-
tract mouthpiece signal from line signal, and know that the tones didn't come
from the Line, and ignore them, or, The phone will recognize them and then
one of two other things may happen.  1. The call will go thru for free. (yay!)
2.  The Call will go thru for free but the mouthpiece will be turned off.
(boo)  - Still, okay for answering machines or for dial-a-whatever services
where you only have to listen.   The next method is a little more involved,
and requires some hardware.  If you have a "Butt Set" (Lineman's Fone) or
a piece of shit 9.95 Cobra phone fitted with alligator clips, you can usually
see on private payphone installations a conduit running from the phone to
somewhere else.   In this conduit runs 2 things:  the 2 wires for the phone
line and 2 to 4 wires for power to the phone (usually low voltage, but be
careful, some phones use 110!!!)  Use a Voltmeter to find the pair that has
the 48-52 volts D.C. across them and clamp on the Butt Set.  - Voila! Dial
tone!  Look for breaks in the conduit to get into, or at the ends.  When
you are on the line in this fashion, there is nothing you can't do.... The
line is very much like a business or residential phone line and you can
call anywhere.  In the next installment, we'll go into Dirty Tricks and
simple mechanical Phraud.

