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Western Electric Preset dial telephone set

Started by paul-f, June 27, 2016, 11:16:30 PM

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paul-f

A few weeks ago, while watching the on-line auction of items from the Tucson Telephone Museum, I was surprised to see a phone that looks like a photo from my web site:

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

That photo (included below) was from a very short note in the July 1966 (50 years ago next month) of Western Electric News Features. It mentioned the set was expected to be used as an emergency phone along highways and by airline and car rental patrons for 24-hour service from otherwise closed reservations counters and was scheduled for customer testing.

In the many years since that item was posted to the site, I haven't seen one or run across any better photos.

Unfortunately, there were virtually no descriptions with the auction and there were only a few exterior photos, showing some damage. There was no bottom photo, which might at least provide a model number and indication that internal components were present. Coming from a phone museum, it could easily be a concept set or display model with nothing inside.

The auction used the non-ebay method of extending auctions for three minutes past the last bid -- eliminating the famous last minute snipe bids. Much to my surprise, with four minutes to go, there were still no bids on the phone.  Throwing caution to the wind, I put in a fairly aggressive bid, which registered as a $5 opening bid, fully expecting it to be quickly challenged.

Then followed three of the longest minutes I've had in quite a while.  :o

When the clock finally ticked down to zero, the $5 bid was still standing - unchallenged!

The final cost was a few dollars higher with buyer's premium and shipping (shared among several items).

After over a week for packing and shipping, I finally received the package and was able to confirm that it is a real phone and marked F-56750, dated 5-66 and with serial number 110.

The dial is marked F-56749, and will be described in more detail in future posts, as I have time for cosmetic restoration and further study.

With all the recent talk about unusual sets fetching high prices, it's nice to find one that snuck through without the usual barrage of high bidders. It's especially nice when it winds up in my collection.   8)


Here are some of the auction photos and a view of the dial.
Visit: paul-f.com         WE  500  Design_Line

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WEBellSystemChristian

Very cool find, Paul! I couldn't imagine a better person for that phone to go to!

If Bell Labs had been more creative, they could have used more telephone concepts and intercom-based phones on the 1500/1560 chassis; a very nice design for button layouts and switches, much better suited than the more rounded lines of the 500/560 chassis. 
Christian Petterson

"Whether you think you can or think you can't, you're right" -Henry Ford

podor

Great find! That's a strong candidate for this month for sure. 

WEBellSystemChristian

Quote from: podor on June 28, 2016, 07:33:27 AM
Great find! That's a strong candidate for this month for sure. 
Hear Hear!!
Christian Petterson

"Whether you think you can or think you can't, you're right" -Henry Ford

Matilo Telephones

Very nice Paul, congratulations.

How does it work? Do you hardwire the fixed telephone number on the terminals at the front?
Groeten,

Arwin

Check out my telephone website: http://www.matilo.eu/?lang=en

And I am on facebook too: www.facebook.com/matilosvintagetelephones

Doug Rose

Kidphone

paul-f

#6
Quote from: Matilo Telephones on June 28, 2016, 05:02:12 PM
How does it work? Do you hardwire the fixed telephone number on the terminals at the front?

Those are among the questions I hope to answer during the research and study phase, which will take some time to fit into the family summer schedule.

The phone is designed to work over the PSTN and call a number of the customer's choosing, so that is the logical way to program it - based on a quick look. Here are a few guesses from observations so far.

Curiously, the terminal columns on the front of the dial are labeled like the columns on a card dialer card - with no * and #.  Based on the phone's date, I'm hoping it's early touch tone and not pulse dialing - and that it turns out to be a "hardwired card-less dialer" (like a card dialer, but hardwired).

The card dialer requires two holes to be punched in each row. Each digit dialed by a touch tone dial has a row and column frequency.

This phone has seven wires attached in each number field. That could correspond to a seven digit phone number. Each wire could correspond to a punch in a dialer card row.

Wires are in color coded pairs. For example, blue/white and white/blue are attached to terminals that decode to the number 2.  Gray/white and white/gray - 1.  Etc.

If true, the digits programmed are 2,1,2,6,7,4 and 9 - not necessarily in order (although 212 is a familiar area code).

There must be logic in the dial to "read" the numbers from the wire pairs in a standard sequence and generate the tones and spaces of proper duration.

Since this set was designed by the same crew that built the card dialers, I'm expecting to find a small motor that provides that function.

There's a lot of stuff packed into the dial. Using a flashlight to peek through some cracks between circuit boards and parts, I can see some nylon gears and what may be the tone oscillator coils.

Without going farther, I'd speculate with some confidence that the dial mechanism is complex enough that it would have been expensive to manufacture and test, and that they could see a short window before the set would be more economically implemented electronically.

It will be fun to sort through this one.

Before scheduling several hours to disassemble and study the dial, I'm hoping to find some more info on the set.  The Bell System must have prepared field trial installation directions and a coding sheet to help the installer wire in the customer's number. It would also be nice to know where the trials were held and how many units were installed.

The set has a ten conductor mounting cord without the usual color coding hints, so the next step of determining where to apply the power and line may take some thought. I have several card dialers, including a 1964 1660 for comparison.

In the meantime, any ideas or speculations are welcome.

Here's a copy of the article that supplied the photo on the site.
Visit: paul-f.com         WE  500  Design_Line

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Stan S

Hopefully Paul's phone is complete.
It would be interesting to see what technology they used in 1966.
Could have been TTL Shift Registers if the design was state of the art for the period, or maybe some motor driven contrivance. Not so state of the art.
Stan S.

oldguy

Paul, have you received the phone yet? If so, have you tried it to se what number it dialed?
Gary

paul-f

#9
Quote from: oldguy on June 29, 2016, 08:18:43 AM
Paul, have you received the phone yet? If so, have you tried it to see what number it dialed?

Yes, and yes.
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Victor Laszlo

"Paul, have you received the phone yet? If so, have you tried it to see what number it dialed?"

Probably 311-KLondike 5-2368

paul-f

Quote from: Victor Laszlo on June 30, 2016, 08:53:59 PM
"Paul, have you received the phone yet? If so, have you tried it to see what number it dialed?"

Probably 311-KLondike 5-2368

Not likely.  See the post above:
  http://www.classicrotaryphones.com/forum/index.php?topic=16426.msg170133#msg170133

The phone was probably installed at a field trial location and was programmed with the customer's desired number.

I'm hoping to find documentation showing the order (by wire color code) of the digits dialed.

If I can't find any helping documents, it will take quite a while to create a wiring diagram and programming list by observation and testing.

In the meantime, I'm working (slowly) on the cosmetics and am creating a "dial card" for display.
Visit: paul-f.com         WE  500  Design_Line

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unbeldi

#12
Quote from: paul-f on July 01, 2016, 09:52:35 AM

The phone was probably installed at a field trial location and was programmed with the customer's desired number.


Why do you think it was a field trial ?

Because it didn't have a catalog number, but an F-number?

F-numbers were used for many limited production items.

The F-number of this one fits into the general time frame of other F-numbers in that period.

paul-f

Quote from: unbeldi on July 01, 2016, 10:29:44 AM
Why do you think it was a field trial ?

I may be going out on a limb here, but the article shown above ends with:

    "The phone is scheduled for customer testing by the Bell System."
Visit: paul-f.com         WE  500  Design_Line

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Doug Rose

Paul....very cool phone. I can't wait to see your pic of it, I think you are correct. Looks like a very early "ring down" type set. No PBX needed.....Doug
Kidphone