Happy touch tone day everyone!

[Matilo Telephones]

Has it been 50 years already? My my, how time flies!

To celebrate I´ll display my red T65 touch tone downstairs.

Maybe I´ll post a picture later.

[brshaffer]

This is an excerpt from a textbook I used in college.  It tells the story of how the concept for touch tone was realized: an idealized re-design exercise at Bell Labs in 1951.   

It's a very, very interesting read.  Both in telephone history, and the approach used.  Amazing that out of one session the foundation for touch tone, voice mail, cell phones, video conferencing, digital displays, etc. all came from one short engagement

The link to the entire article:
http://knowledge.wharton.upenn.edu/article/idealized-design-how-bell-labs-imagined-and-created-the-telephone-system-of-the-future/

We decided to see if we could design a phone that met the requirement of no wrong numbers. An amazing thing happened; in less than an hour, we found a way, conceptually, to reduce, if not eliminate, such errors. We replaced the dial by — what did not exist at that time — a small handheld calculator. There were ten keys, one for each digit, a register, and a red key in the lower-right corner. The phone was to be used as follows. Leaving the phone "on the hook," one would put into the phone the number one wanted to call by pressing the appropriate buttons. These numbers would appear on the register. If these numbers, on examination, appear to be correct, one would lift the receiver and the whole number would go through at once. If the number on the register was wrong, one would press the red button in the corner. This would clear the phone, and one would start over.

We were very pleased with ourselves, but nevertheless we recognized that we did not know whether such a phone was technologically feasible. (The handheld calculator was not yet available.) Therefore, we called a department of the lab that worked on miniaturization and asked for technical help. They sent two young men down to our meeting. They appeared to be fresh out of school, still wearing their intellectual diapers.


As we described what we were trying to do, they began to whisper to each other and were soon more absorbed in their private conversation than in what we were saying. This bothered us, but such behavior was not entirely unexpected in an R&D laboratory. However, they suddenly got up and hurried out of the room with no explanation. We were furious but decided to let it pass for the time being. We went on to another property.


Several weeks later, the young men appeared at one of our sessions looking sheepish and apologetic. They said, "You probably wondered why we ran out on you when we were here last." We told them this was an understatement. They explained, "We were very excited by what you were doing but not for the reasons you were. We did not want to take the time to explain. That wrong-number stuff was not as interesting as the buttons."


They went on, "We went back and built a push-button telephone and tested it on a very large number of people. It turns out to take about twelve seconds less to put in seven digits by pushing buttons than turning a dial, and additional time is saved by not occupying a line until after the number is put in and the receiver is picked up. The combined saving in time is worth millions to AT&T," they said, "so we have started a project to develop that telephone. We have given it a code name that is being kept secret for now." They looked around the room to be sure no one was listening and then told us, "Touch tone."

[paul-f]

Has it been 50 years already?

Thanks for the reminder.

Yesterday was the 50th anniversary of the day credited by AT&T as the date of the first commercial installations of Touch Tone sets in Carnegie and Greensburg, PA.  (11/18/63 - "Events in Telephone History" AT&T)

An article in Sunday's Pittsburg Tribune-Review commemorated the event in the two local towns with some photos.
Here's a link to the article.

http://triblive.com/news/allegheny/4291278-74/touch-phone-tone#axzz2l1B0JCQF

Greensburg, PA was also a field trial city for the F-53700 set. More on the development of the touch tone instruments is here:

http://www.paul-f.com/weprotot.html#WE1500


The notion of preset dials using a calculator model to minimize wrong numbers had been in development for many years.  A favorite example is shown here:

http://www.paul-f.com/weproto.html#Other

[Phonesrfun]

I remember the touch tone demonstration at the AT&T pavilion at the 1962 Seattle World's Fair.  It sure wow'd me.

[WEBellSystemChristian]

I remember the touch tone demonstration at the AT&T pavilion at the 1962 Seattle World's Fair.  It sure wow'd me.

Imagine what those demonstration sets would go for today...

[WesternElectricBen]

Huh, my calender doesn't say that!!

I guess its not a Holiday yet.. Well, I'l have to send in a complaint to the publisher of it.

Ben

[unbeldi]

This is an excerpt from a textbook I used in college.  It tells the story of how the concept for touch tone was realized: an idealized re-design exercise at Bell Labs in 1951.  

Hmm, 1951? This story seems like a bit of fiction.
Bell Labs had been working on push-button dialing in the 1940s, as early as 1941 or so, IIRC.  In the late 40s they ran field tests with push-button telephone sets that used reed relays for frequency generation, but the relays proved too vulnerable and unreliable for general use. It was the invention of the transistor that change it all in the 50s and made reliable instruments possible.

In the late 50s and still into the beginning of the 1960s they experimented with the layout of keys, testing various configurations.

One aspect of the story seems somewhat correct though, namely the statement that the Bell System had  been hardly an innovative driver of technology, instead on many fronts improving on existing technology, and coming late to the advent of automatic machine dialing, integrated handsets, combined telephone units, as well as integrated network (coil, condensers, etc.) components. The transistor certainly changed that.

[unbeldi]

Years before the official introduction of TouchTone, push-button dialing was already in 1956 a practical reality in Holland at Philips, where they operated this push-button or keyset dial with the UB-49 PABX.

However, being a direct current-based relay mechanism, it was only usable for direct connections to the number register unit of the PABX,  whereas TouchTone could be operating on long-distance lines through repeaters and amplifiers, as the signaling is provided by in-band audio frequencies.

[G-Man]

Unbeldi is correct that on many levels there is something fishy about this story, especially how a non-employee of the labs helped develop instruments DTMF (Touch-Tone™) signaling. He also does not appear to understand that the dial-pad is not related to a handheld calculator other than both having push-keys.

I suspect that this is an attempt at self-aggrandizement that would be difficult to otherwise dispute since most of the key players have most likely since passed-away.

It is somewhat ironic that both frequency selective ringing and tone-signaling paralleled Bell's original experiments before he attempted to transmitter the human voice over a pair of wires. 

As unbeldi pointed out, the first attempts with subscriber tone signaling used tune reeds, similar to what Bell had attempted, for signaling the central office switching equipment.

[Matilo Telephones]

According to this article Multi frequency dialing was already conveived in the 40ties.

http://en.wikipedia.org/wiki/Push-button_telephone

Anyway, here my pic. T65 made by Ericsson in1982.

I´ll used it downstairs for the coming week.

[G-Man]

"One aspect of the story seems somewhat correct though, namely the statement that the Bell System had been hardly an innovative driver of technology, instead on many fronts improving on existing technology, and coming late to the advent of automatic machine dialing, integrated handsets, combined telephone units, as well as integrated network (coil, condensers, etc.) components."

Actually, in that regards, the opposite was generally true; a good portion of their research was not just telephony related but devoted to the pure sciences. That is the one of the reasons their research was heavily lauded world-wide.

Previous to Divestiture they could afford that luxury since their funding was coming out of an assessment on all of AT&T's local operating companies along with Western Electric, Long Lines, etc., etc.

It was only after the breakup of the Bell System that their mission was changed to the research of closely related fields that would be more lucrative for their owners.

A quick review of the index of the Bell Labs Record or Bell labs Technical Journal will reveal numerous topics concerning research directly unrelated to telephony. The results of that research was ultimately beneficial to the Nation and the World at large.

Here is a description from Bell Labs of their work:


The scientific discoveries and technological innovations produced by Bell System research and engineering were critical not only to the evolution of global telecommunications but, more widely, they had a considerable impact on the technological base of the global economy and, indeed, on our daily lives.

Bell Labs is the source of many significant contributions, of course, in the area of telephony, but also in memory devices, imaging devices, system organization, computers and software technology, as well as acoustics, optics, switching, transmission, wireless and data communication.

New principles, new materials, new devices, and new systems from Bell Telephone Laboratories resulted in new industries, hundreds of new products, and thousands of new jobs. The invention of the transistor in 1947, and subsequent advances in related solid-state device and circuit technology formed the basis of a multibillion dollar global industry and ultimately enabled the digital world.

Shannon's seminal paper titled "A Mathematical Theory of Communication," published over 60 years ago, gave birth to Information Theory and has stood as the guiding foundation for communications scientists and engineers in their quest for faster, more efficient, and more robust communications systems ever since.

The charge-coupled device (CCD), a technology that transforms patterns of light into useful digital information, is the basis for many forms of modern digital imaging. It has launched entirely new industries and markets and is widely used in devices as diverse as digital cameras, video cameras, and bar code readers as well as in security monitoring, medical endoscopy, modern astronomy and video conferencing. Optical technology and systems, from earliest advances in lasers to low-loss fiber, opto-electronic waveguide devices, and high capacity WDM transmission systems have enabled worldwide connectivity to build a truly global community.

Cellular telephone service, the concept that multiple lower-power transmitters could be spread throughout a region employing automatic call handoff and frequency reuse changed the face of communications. Multiple input multiple output (MIMO) smart antenna technology in concert with LTE, based on OFDM technology, will define next generation wireless, delivering wider coverage and higher throughput.

"Technological innovation" is more than just invention. It is a process, often long and costly, of transforming new scientific knowledge into feasible technology, introducing it to use, and making its benefits available to the public. "Technical integration" is intended to emphasize the more subtle flow of an intangible—engineering information and understanding. Not only has Bell Labs innovated, but it also showed the world technical integration of the innovations.