Cunning idea to avoid phone bills, twenty years ago: would it have worked?

I was just thinking - with the phone equipment around twenty years ago (I assume everything is digital now at the back end making this impossible) could you have averted paying phone bills by hacked phones that when they were called didn’t indicate that they had picked up (i.e. seemed to the system to still be ringing) - or did the voice circuit not connect until the phone answered? You would think given how complicated some voice circuits could have been, especially internationally, they at least had some kind of pre-connect mode otherwise there could have been a considerable delay after someone did pick up. Or maybe there in fact was?

Read up on phone phreaking or blue boxes.

I don’t know about this specific described hack, but there were many such hacks and exploitable flaws in the analog phone systems back in the day. Look up phreaking and the exploits of people like Captain Crunch, some phone systems could be hacked with a toy whistle!

And in fact a link directly off that hascopied my idea. So clealy those phreakers also had time machines.

I don’t know if the voice circuit would be connected or not, but the ringer would still be going all the while, which might make it hard to carry on a conversation.

Abby Hoffman’s “Steal this Book” encouraged you to build a “black box” using a capacitor and a switch. The idea was to prevent the phone company from knowing that the phone was off hook. You couldn’t make a free call, but supposedly someone could call you for free. When the phone rang, you were supposed to pick up the phone, then flip the switch to disable the ringer.

That book was a piece of trash, but I enjoyed the description of this little construction project, which was written so that people with no electronics background could do it. "… then go to a radio repair company and read this to the clerk: ‘Excuse me sir, but I want a one micro farad electrolytic capacitor with a rating of 100 volts, please.’… " or something like that.

More like 40 years ago than 20. The system didn’t do signalling on the same circuit as voice 20 years ago, which is how blue boxes worked.

One similar trick for payphones was to put a diode in the wire the operator used to drop a coin. She got the signal that the coin was deposited, but when she tried to make it drop into the coin box the signal never got through, so the coins were returned after you made your call.

Yes, what you were describing was an actual problem for the phone system.

AT&T has a patenton a method to defeat this problem. (The patent may now belong to Alcatel-Lucent if it has not yet expired.)

The solution is not to open the forward voice path until answer supervision is received from the remote end. In other words, if the called party has a hacked phone (more likely a hacked or malfunctioning PBX system), they won’t be able to hear anything that the calling party says.

The voice path is not disabled in both directions so that the calling party can hear announcements such as “The number you have called has been disconnected” and so on.

If the called party is behind a PBX, it is perfectly legitimate for the PBX not to return answer supervision immediately upon connection from the Telco, because the PBX is responsible for ringing the dialed extension. The problem comes in when the PBX does not return answer supervision after the dialed extension has answered (as it is supposed to).

My grandparents lived in a rural community that was served by some phone company other than THE TELEPHONE COMPANY. That phone company had some weird pay telephone where you deposited the coins after the other party answered the phone. If you didn’t put the coins in, you could hear them to talk to you, but they couldn’t hear you.

Some phone hacks were social instead of mechanical or electrical. As a kid, if I traveled a long distance, I would place a collect person-to-person call to my my parents house from me to my dead uncle.

My parents would pick up the phone, state that uncle Emil wasn’t there, refuse the call, and receive the code that I had arrived safely. Many of my friends did the same thing. On Sunday afternoon and evenings there were probably a few hundred person-to-person calls to dead relatives from university towns.

I’ve seen plenty of similar pay phones. There was one at my school and I used a similar system to what BubbaDog described. If I was staying late after school (I was kind of addicted to tennis and that was the only place to play) I’d call my mum. She’d hear nothing but she’d know from the time and the phone number that it was me saying I’d be back later. Since I could hear her talking she could always let me know if I couldn’t stay, for some reason.

I think what the OP is refering to is making a long-distance call by using a series of what looked to the phone company as short local calls so you could call anywhere in the US for free.

There was a time about 1990 when some kids were in the news for discovering a series of numbers that could be punched a phone and do something devious. I don’t recall the details. I am reasonably sure the news stories were between 1983 and 1994. Perhaps some of the links above are to this method.

“I have a collect call from Mr. Itsaboy. Do you accept the charges?”

janeslogin - Most likely, the kids found test lines that were intended to be self-answering with silence so the linesmen could dial in and assess things like the amount of hiss or hum on a line. Kids found out that they could call these lines and have free party lines. About 25 years ago, I made some timer circuits for a local phone company that would kill the line after 30 seconds - enough for the techs to do their work, but too short to be any fun for the kids.

I worked in a call center for a LD Telco in the early 90’s. A group figured out a way to get ‘free’ LD calls.

Call the toll free number to customer service (Sprint for example). Ask the rep to transfer you to another carrier’s operator(AT&T for example) .The operator you were transferred to would see you as calling from the BTN of the call center that transferred you. Once on line with that operator, ask them to place an operator assisted call to wherever. Free long distance call and the call center who initially transferred you got the bill.

Re-reading my above post, I felt that “a group” may give the impression that I meant a group within the company. I meant an outside group. We as call center reps just began wondering why we began getting several calls a day asking to be transferred to another carriers operator.

Eventually we were told not to transfer such requests any more. We were told people were selling unlimited LD calls via the scam. A phone bank or airport in the caribbean. $10 or whatever for an unlimited LD phone call to your relatives back in the states. Scammer got a 10 and used the above method to hook the person up with the call.

What you’ve described (I reckon you know) is a red-box and these worked well up into the late 1990’s.

I wonder how old the OP is? I wonder because they used “20 years ago” as their example. That was 1992. I remember reading about phone phreaking, cap’n crunch, alt.2600 around that time and most of those techniques were already useless in the early 90’s.

OK, disregard my previous comment… what you described isn’t really a redbox, though redboxes did work up through the 1990’s. A redbox was an audio dialer where you replaced a certain diode to make it emit coin tones. There were no actual coins required at all.

Redboxes did indeed work well into the 90’s, I had to use one daily 1994-95 because I was broke. However there was no need to buy ($, god forbid!) a Radio Shack dialer and mess with the innards. If you had a computer with a sound card you had what you needed to generate the tones.

To get the tones portable you could either use a Hallmark voice greeting card or record a bunch of quarter tones on a cassette tape and use a Walkman tape player with a built in speaker.

The problem with the Walkman was the cassette tape would wear out after being played so many times and the tones would degrade to the point where the telco wouldn’t automatically recognize them. This, unfortunately, would automatically trigger an operator to jump in and see what is going on. I absolutely panicked the first time that happened. She asked me to deposit the money and I played the tape. She said “well sir I can hear that you’re depositing the money, I don’t know why the computer isn’t recognizing it. I’ll put your call through for you.” Awesome.

The other color box that still worked around that time was the one where you could play tones to cause a pay phone to dump the coins that were deposited for that call. This only worked when the tones were played from the other end; you couldn’t play them into the pay phone and return your own money. Whenever my friends called me from a pay phone, if I was near my computer I would ask them to hold on and then fire up the software. beep beep. The amazement in their voices as their coins dropped out was priceless!

I think that one was called a green box. Not sure; didn’t look it up today.

And so many of the lesser box colors were shared / fought over so a given color didn’t always mean the same thing anyway. 75% of the oddball coloured boxes were absolute BS that never could have worked.