YIPL No. 20 - July 1973
The local A&P has two pay phones but they ripped out the number plate since the A&P chain doesn't want the public to know the number of the pay phones in their stores. I tried dialing 958 but it didn't work (although it works in other pay phones). Any ideas why 958 didn't work? Can A&P request the telephone company to disconnect the Automatic Number Identification from its phones? -,T. R. , N. Y. -
Could be that the exchange of the particular pay phone has another
ANI number. Try ringback, the bell may have been deactivated anyway.
Complain to the manager that someone might have to reach you while
shopping, and you might go to a store that doesn't make already lousy
service even worse. But it isn't likely Bell disconnected ANI just
from those pay phones.
Hot News Item! In issue 11 we stated that the Black Box is primarily for long-distance call , and that local calls may be disconnected if the switch is not immediately switched to "Free". Tests in several areas of New York show that local calls will not be disconnected and will be free. Calls from a pay phone will also be free. There are reports that certain areas will disconnect local calls automatically in 10 to 30 seconds, but often the phone is picked up and hung up too slowly, thus accounting for the disconnection. If the procedure is done within 1/2 second, no disconnection will, occur, unless the local phone system is so designed. Highest safety will be afforded when calls are kept under 3 minutes.
A recent rumor flying around Washington was that there was a number, 560-9944, that made a rising siren tone with a click if your phone was tapped, and no click meant no tap. NBC anchorman John Chancellor called the number and heard a click, so he called the phone company. They told him they disconnected it because people were making too many calls to it - falsely thinking that it told of phone taps. An army intelligence source told the N. Y. Post that there was a similar number in N. Y. , but he didn't know it. If he had read YIPL #14, however, he would have, 324-0707. This number, to our knowledge, was not a bug detector. It is a test number that swept through the frequencies of the long-distance circuits. When it reaches 2600, there is a momentary click because test men using it long-distance don't want to be causing extra switching when checking a line. Also filters in all, long-distance trunks would cause the loss of the tone at 2600 anyway. The Telecommand (YIPL #3) detects a tone sent down a line and silently answers the phone. If you suspect a Telecommand on your phone, and were to feed a rising siren tone into your phone, you would hear a click when the frequency of the Telecommand was reached, and the click would mean that the Telecommand had just turned on. Since the chance of a Telecommand being on your phone is small compared to the many more common taps, using the phone company's sweep tone could prove to very misleading, at the very least. Since the rumors began, both the Washington and N. Y. numbers have become busy signals. So it appears that a common test number useful for one limited type of bug detection and no others has bitten the dust.
THE CHEESE BOX
The Cheese Box is simply a conference line, or loop-around. They are very popular with bookies who place bets by phone, because their clients call one number, and the bookie calls another, and police won't find the bookie at the location of either of the two numbers. This is precisely why loops have been a favorite of phone phreaks, too.
Bell's loops are limited because they often disconnect after a certain time, one of the two numbers must be called first, and they are often monitored and sometimes even charged. The Cheese Box can be extended to many lines, thereby creating conferences, and will let either line be called first and hang on indefinitely. Last but certainly not least, the Cheese Box is free.
Phone voltage is normally 45 volts. When the phone rings, a 90 volt AC signal is applied to the line. The zener diode conducts if the voltage rises to 56 volts, thus it conducts as the phone begins to ring, in fact, before the phone rings. As soon as it conducpts, the phone equiptnent thinks you picked up (because current is drawn by the zener) and the voltage drops below the zener voltage, and it stops conducting. All this happens so quickly that essentially the zener conducts for only a few milliseconds, and the billing equipment does not start. If you call from a local-pay phone, you will get your dime back. And you can hold on until someone calls in on the other line -or lines. When they do, their line will be answered in the same way and you can then talk to each other. The capacitors prevent the DC voltages on the lines from interfering with each other. Either side of the line can affect the line status if allowed to touch another line.
Install the zener diode to the red and green wires of your phone line. If you install it backwards, there will be no dial tone on your phone, if so, reverse the wires from the zener.
A zener diode will conduct electricity when the anode is more positive than the cathode, or when the cathode is more than a certain number of volts more positive than the anode, in this case 56 volts.
Since the phone company has a special hatred for phone attachments that cause free calls, many bookies use the Cheese Box for only a few minutes, since calls over 3 minutes can be detected if the phone company decides to do something about it.
You are cordially invited to the 2nd annual Phone Phreak's Convention
BE SURE AND BRING AN ISSUE OF YIPL ADDRESSED TO YOU FOR FREE CONVENTION ADMISSION.
It's reasonable to assume that these people will only supply
independent companies. The Bell system has designed its - own. It's
been known for some time that Bell has had a fe~ 2600 detectors that
recorded the MF numbers. These are probably used when they suspect a
blue box is being used from a home phone and want to gather evidence
for prosecution. According to Bell security, the computer program
which processes the billing tapes now looks for 800 calls longer that
10 minutes as well as an excessive number of 800 calls.
YIPL No. 20 - July 1973