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Now the Story Can be Told - 1949 WECo 500 Set

Started by Dan/Panther, March 20, 2010, 11:08:11 PM

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I've added another interesting point to the Dreyfus photo. Note the finger stop, it's the early weaker design, like in my phone. this all but rules out the possibility  that the Dreyfus photo is a production set, and most likely is Pre-production and quite possibly 1948 or earlier.
Note that the above posted excerpts from the article listed by CIHensley, my phone could possibly be a 1947-500.


The More People I meet, The More I Love, and MISS My Dog.  Dan Robinson

Here is a May 1952 BLR article on the 500 set dial.


You have a superb library of Bell related articles. Excellent reading material.

Thanks Jorge.

Here is an article on the G handset for the 500 telephone from the August 1952 BLR.



That appears to be a book. What book is it ?

The More People I meet, The More I Love, and MISS My Dog.  Dan Robinson

D/P - It appears to be a book, but is and isn't. What I copied from was a collection in which all 10 issues for any year were bound together in a single volume. Like taking all of the issues of say 2009 Newsweek magazine and having them bound in a single volume.




Chuck's article posts provide a who's who of insiders on the 500 development with some biographical info that may help you track them down.

W. L. Tuffnell, Station Apparatus Development
W. R. Neisser, Transmission Apparatus Development
R. E. Prescott, Station Apparatus Development
L. J. Cobb, Station Apparatus Development

Others mentioned:
W. Pferd
J. H. Ham
H. W. Bryant

Most of the authors graduated or came to the Bell System in the 1920s -- probably making them over 100 years old.  From the photos, some of the others may have been a few years younger.  Secondary info sources are looking more promising!
Visit:         WE  500  Design_Line



It looks like the best we can hope for may be a relative that has some personal papers.

The More People I meet, The More I Love, and MISS My Dog.  Dan Robinson

Here is an article on 500 set gongs from the September 1957 BLR.



Excellent reading material Chuck. I wish I could find a set of gongs other than the standard issue, but so far, no luck.


Quote from: JorgeAmely on July 02, 2010, 12:54:07 AM
Excellent reading material Chuck. I wish I could find a set of gongs other than the standard issue, but so far, no luck.

You would probably only (or mostly) find them on 565 keysets that were used in large offices.  Even then, since the phone company probably charged extra for them and had to order them in special, probably only big companies and the gub'ment were able to spring for them.

You might try a collector who deals in key systems.  One that comes to mind is Phil McCarter in Oregon.  I can get you a phone number for him if you wish.
-Bill G

Jim Stettler

I don't know if this was mentioned yet:

TCI is offering a reprint of the article about D/P's phone ($5.00)

Russ's little booklet of colored 500 sets is also offered (12.00)

If you decide to order a copy I suggest you also get the 20+ years of newsletters on disc ($20.00)

You live, You learn,
You die, you forget it all.


Just finished reading this entire thread (over a period of a week or so) and I have to say, I'm just in awe.

Not only because Dan appears to have found and resurrected the earliest known 500 set, which is of enormous historic significance, but also because this became a project of the entire community, with everyone engaged in a spirit of cooperation and teamwork.  That kind of cooperation and absence of selfish attitudes is the way things used to be, before the "greed is good" era and its sequelae.  I can think of a few hundred people in high places such as elected office and on Wall Street, who should learn a lesson from that.  

I think we're looking at a pre-production unit from 1948 or earlier, one of a very very small batch.  The uniqueness of all the design elements, their match with the patent diagrams, and the "return to Bell Labs" stamp on the bottom, all point to that conclusion compared to any other possible conclusion.

My earliest example is a date-matched 1952, but I'd love to get hold of a 1950 to be able to hear the difference in subtleties of audio quality between the equalizer and the 425-B network designs.  


Tech stuff and question:

Re. filament-based equalizers in early WE 500s, and PBXs:

Possible way to get around the issue of the lifespan of those regulator filaments. 

At risk of sounding heretical, if you want to use a set with an equalizer, I'm going to suggest bypassing the regulator altogether and installing a simple dropping resistor based on what works on your CO loop or PBX loop (see below re. PBXs).  AE did this with a variable resistor in their network circuits, that the installer would adjust upon installation, to produce a given current reading on the test board of 60 mA DC.  You could do similarly with a plain fixed resistor rated 1 - 2 watts, and a terminal strip tucked out of the way somewhere. 

The above arrangement would result in a fixed value but chances are you would not notice any changes in sidetone when you were dialing out and talking. 

On an electromechanical PBX you might get a metallic connection to the CO line whereby your loop suddenly increases from e.g. 100 feet to a mile or more.  But on any modern PBX e.g. Panasonic, that is not the case: the CO line card in the PBX takes care of it for you and your loop characteristics remain the same whether an intercom call or a CO line call. 

Re. the "swoop" on the fingerstop, and the reinforcing projection on the production version: 

Dan's example is mounted with a screw into the fingerstop itself.  I think it's highly likely that that construction would have become more prone to loosening over time than the production #7 dial where the screw is through an opening in the fingerstop into a thread in the dial base.  A thread in the dial base would pass through thicker material enabling the screw to be tightened more so than if the thread was in the thinner fingerstop, thus preventing loosening over time.   And at the time that change was made, the actual shape of the fingerstop may have changed a tiny bit for whatever reason or just incidentally with no specific reason. 

Also the projection that sticks up through the numberplate may have been intended to provide added rigidity to the fingerstop to prevent it getting bent or twisted slightly out of alignment during its expected 40-year lifespan.  The projection also helps to locate the number plate onto the dial mechanism during assembly, which may have been helpful for field techs who had yet to become familiar with the new dial.

Re. the varistor in the earpiece: that served one purpose, which was acoustic shock (click) suppression.  Varistors and other components in the 425-B network block served to compensate transmission to loop length.  I have never seen a U1 receiver element without the 44-A varistor ("tin can") across the terminals (obvious exception for U1s in which the varistor was replaced with the "green TicTac" type).  Any example of a U1 that did not have a varistor on it, would have been a production error: one that got away on the production line before the assembly worker had the chance to grab it and put the varistor on it. 


So what's the status of this project at this point?  What ever became of the person who was said to have a 49-500 but was reluctant to release photos? 

Did the Smithsonian ever respond with possible interest in borrowing Dan's phone for an exhibit?  (Don't give it to them: some future budget-cut could result in it getting auctioned off and ending up in unappreciative hands or becoming one of those "objects that are worth too much money for human hands to ever touch" situations.) 

Have any other extremely early 500s ever turned up since then? 


Thanks for all the comments and suggestions. Yes this was a joint effort, and would not have been possible without parts and help from several members.
I had hoped that this thread would have encouraged the owner of the alleged, 49-500 to come out and share the phone. It appears that the owner fears theft of it. Though a real possibility, I think it overstates the true value of the set. Their are other known parts and at least one documented set on display. Outside of the Phone collectors community, I think there may not be wholesale interest in a vintage telephone, so at best I would value a unique telephone at the low thousands of dollars. Even though I myself would hesitate to part with my set for less than several thousand dollars, chances are if auctioned, in reality I doubt it would garner what I feel is it's value to me.
This project was my 15 minutes in the spotlight, and I would not trade that for anything.

I never heard back from the Smithsonian, so I figure they either have a prototype 500 or they don't care. The former is my guess.
Here is a side note I found out about the Smithsonian, while visiting the Wright Brothers Museum in Dayton, Ohio. The Smithsonian has exclusive rights to display the Wright Flyer, AS LONG AS THE WRIGHT BROTHERS ARE GIVEN CREDIT FOR THE FIRST FLIGHT OF HEAVIER THAN AIR VEHICLE. IF THAT IS EVER OVERTURNED THE WRIGHTS MUSEUM WILL REVOKE THE FLYER.

The More People I meet, The More I Love, and MISS My Dog.  Dan Robinson