# payphone trick

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#### evoke

##### New Member
i was thinking of a new project i want to find out about. i was going to research it on the net but i just wanted to tell the forum the theory of it first.

telephones work on pulses.every number you type has a pulse. i was wondering if i could make a pulse that i could feed into a payphone through the telephone mic or through radio frequncies so that the payphone would activate because it thinks that the money is payed.

Do you think this theory would work. Even if i make the device i dont know how i would find the pulses to activate the phone.

Just to get a thought of anyone in the forum.

It would be purely educatioal aswell. because i would learn from this project that i can command circuits through radio waves if it is possible

#### Sebi

##### Active Member
The idea can't work, because the payzone pulses activated the coin magnet, and if no coin presence, broken the line...

#### evoke

##### New Member
i dont understand you need the coin to make a current.

can you tell me again. is there any other way of doing it

#### daviddoria

##### New Member
i think this is referred to as a "blue box" (not sure)

i think that idea used to work, but as he mentioned i believe now there is some sort of circuit that is closed only when there is a coin in the coin holder.

#### evoke

##### New Member
the circuit is in a box. so no radio waves can through this box. is it wnbreakable.

I was going to send a radio wave that would trigger the circuit to think there was a coin put in.

is there any other way do you think. any other nethod of getting into the box without opening it.

#### Gene

##### New Member
When I was in college, payphones were tricked with a penny, a bi-tone generator box, and a small give-away item (no, I'm not telling) from a resturant. Of course, the phone company removed the phone from the dormatory when it was found to be full of pennys for several months. I have also heard that this method has been blocked by better technology.

#### evoke

##### New Member
yea but i want to do it with electronics. i want to trick the phone with electronics so i can learn from it. i think there is some way of doing it. someone in the forum must have heard of one. the only way i can think of is using radio waves to make the inside circuit think it has a coin put into it.

#### Sebi

##### Active Member
I try explain step-by-step the line connecting with my bad english, sorry.
insert a coin - it falled into coin-recognizer,and stoppped by electromagnetic gate.
dialing - all the same with pushbuttons or external DTMF generator via microphone
the phone-centrale know from dialed number the payzone and generate an impulse (about 4500Hz, 1sec) and in phone pull the coin-gate magnet - the coin falled into basket. If the coin value smaller as need for payzone minimum, it falled out. The phone-centrale hold connection the coin-determinated time, and send a new impulse. When new coin not present until impulse, the line broken.
the coin-recognizer communicate with phone CPU via serial line.

#### JCOhio

##### New Member
If a coin is required for the circuit then why can you make a toll free call or a collect call from a payphone without a coin?

#### Sebi

##### Active Member
This depend from country. In my country i can also can build a call without coin, but when the receiver make hook off, (here coming the coin-magnet pulse) without coin coming a busy signal. An this procedure work only wth local call.

#### compute_a_nerd

##### New Member
Yeah, Steve jobs, and John T. Draper a.k.a captain crunch were the masters of this in the day. They invented a blue box that would basically hack into the phone lines, They blew a 2600 tone into the phone (eithor by whistling, or by using a captain crunch whistle, no longer made hence the name captain crunch)which would break into the system. Anyway there was a huge media story about it, and ever since the late 70's tons of new technology has been put in to make it impossible.

#### evoke

##### New Member
so the coin is needed to make the circuit work. does the coin have a currnt going through it .if it is i think there is a way of tricking it.

what DTMF mean. so you need some kind of circuit that will make it look like the coin is there and let the current run through it.

Im not sure if i understand.but i am getting there. :arrow:

thanks

#### Skyknight

##### New Member
Once ago, I bought a phone. This phone came with some accesories. One of them was an independent device: Just a little keyboard, similar to the mobiles keyboards and, on the back of the keyboard a simple speaker. It was just a tone generator. It wasn't for the telephone I bought. It was for any other which worked with pulses not with tones. All you had to do was to bring over the mic of the pulse telephone this device and press the key combination. The old telephone would "hear" those tones and would make the call. I've never tested it in a public phone. But, I think it should work.

#### evoke

##### New Member
thats what i was thinking. but the other lads said it wouldn`t work. can you test it out for me and see if it works. tell me what happens. it might still work

Thanks

#### Skyknight

##### New Member
OK I'll try to test it. But not now (13:24) I'll try tonight or whenever no one could see me "hacking" the telephone company I can try just now if you only want me to test it on any phone such as the one I have at home.

I've added you to my contact list in MSN messenger, but you weren't available. I'm [email protected]. Enter msn if you want chat instead of loosing time with mails in the forum :wink:

#### zambo

##### New Member
I have blue Box Plans as well as a software simulator

Zambo

#### evoke

##### New Member
can you send me the blue box plans please or post them in the forum for everyone to see

#### lavenatti

##### Member
Heck, you used to be able to put a 470 ohm resistor across the phone lines. The CO always thought the phone was on the hook. All calls to that phone -free.

#### bmicomp

##### New Member
It's called a red box. YOu can't use them at all payphones as the phone company is phasing out the phones which these will work on... but you go to radioshack, get a tone dialer. Then you replace the crystal with a 6.5536 mhz mouse crystal. You can find the schematics anywhere.

#### Nostrafus

##### New Member
Aiight, here's the thing, the idea of a blue box doesn't work anymore, the original tone based phone systems ran by using specific signals, 2600 was the frequency at which the phone would grab a line opened, (hence the name of the web site and quarterly publishing, which I surprisingly found a book store that carried it, didn't realize anyone in the US carried that thing) and the buttons on the phone would make different tones to identify which was being pushed.

Now, the newer phones in the US run on a dual signal, meaning you have to get a blue box that oscillates between 2 different signals at once (nearly impossible to make a portable version of) since the signals have to happen at the exact same time, making one is extremely difficult since it would have to be 2 blue boxes running on 2 different frequencies.

Honestly I'd just look into building one of the old ones and framing it, besides, it'd be cheaper just to use the current price, I mean honestly, would you really spend like \$50 for all the research, burned out parts, screw ups, etc. necessary to make a phone call ?

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