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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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Phonesrfun

Quote from: McHeath on March 30, 2010, 07:31:25 PM
As far an what use an equalizer has on modern lines I don't know.  I do know that my 1951 J/K model 500, which has the 425A network and no equalizer, has annoyingly loud sidetone.  So annoying that I put a resistor on the terminal block to reduce it to tolerable levels, and now the phone is quite pleasant to use. 

But I don't know if this was a problem with having the 425A network and no equalizer.

Really nice that Paul put the blueprints up for the 500 series on his site, and they are just like the phone that D/P has!

This is absolutely the case.  A 425A network with no equalizer is basically the same as a 302's 101A induction coil and using the T1 and U1 combination of receiver and transmitter.  That is what the 1949 Bell System article authors were talking about when they said that the 425A network with the U1 and T1 on short loops without the equalizer would be intorlerable.

Your resistor accomplishes what the equalizer is designed to do, except your resistor is fixed and the equalizer varies on current.
-Bill G

McHeath

That perfectly explains what was happening.  I assume that the J/K series and other 500s made without equalizers in the early days of production must have been installed at certain distances that did not need the benefit of the separate equalizer unit.  A cost savings I guess.


rp2813

It's looking like it's no question that D/P has a definite field trial set according to the list a couple of posts up.  He has the non-riveted feet, horzontal plunger levers, a molded-character bezel and an unfamiliar ringer mount.  Enough research could maybe uncover a time line for when the various changes were made during the trial period.

This is about as close to the holy grail 500 as we're likely to see.
Ralph

Dan/Panther

#303
I posted this in the wrong forum. What a\n idiot. I need to step back for a while I'm losing it.

Paul;
I have a couple quick items I would like clarified if you can.
In the first photo, what is the locked screw used for ? Is it an adjustment, or to hold internal parts in place ? I would assume all components were attached to the Black cover.

In the second and third photos, the number 125 appears on two separate components and you can see 124 on the ringer. What do these designate? I thought component numbers but two different components with the same number ?
there doesn't seem to be a definite pattern to the 3 digit numbers or the D177 numbers ?
D/P

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

Dan/Panther

The rear dial protective cover is Tenite, and warped beyond use, the mounting screw was missing so it was floating around for half a century and even with a new screw, would rub the gears. So I must make a new one. I use a method borrowed from Radio work. It's a wooden mock up, then Polycarbonite sheet is heated and force formed over the mock up. Cooled then trimmed. Here is the Mock up ready to be used to form the new Dial cover.

D/P

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

JorgeAmely

#305
D/P:

The 125 number is probably the kit number for all parts in a set. When the set was being assembled, someone must have borrowed a part (or the part was found to be defective) and the assembler took a part from the next kit to assemble this set. My theory and I am sticking to it.

The nut in the box is most likely a method to secure the bulb that contains the filament and thermistor so it doesn't rattle inside the box if the set is accidentally dropped. I haven't looked inside one of those boxes before, but in case there is a potting compound inside (to secure the bulb), then the nut is probably used to secure future accessories inside the phone. I kind of doubt this theory because the screw does not protrude much above the nut.

My February 1950 set does not have such nut.

Could it be possible to heat the dial cover with a hot air gun and try to bring it back to the original shape?



 
Jorge

Dan/Panther

#306
Jorge;
Tenite is so fragile, I'm sure I would either make it worse, or break it completely.
I would rather display all of the broken or worn out parts next to the completed phone, and save them as they, are rather than take a chance. they have slightly yellowed or amber colored polycarbonite, it should look almost like original.

D/P

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

Dan/Panther

Quote from: JorgeAmely on March 30, 2010, 11:19:54 PM
D/P:

The 125 number is probably the kit number for all parts in a set. When the set was being assembled, someone must have borrowed a part (or the part was found to be defective) and the assembler took a part from the next kit to assemble this set. My theory and I am sticking to it.


Jorge;
If I understood Paul, this is similar to what he explianed to me, but I still have issues because the network is 209, the EQ is 35, sure looks like a lot of defective parts, and I find it somewhat hard to understand why they would have such an unorganized numbering system. Especially for field testing. Somewhere, someone is sitting on a ton of Field test documentation.

D/P

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

Jim Stettler

Quote from: Dan/Panther on March 30, 2010, 11:39:47 PM
Quote from: JorgeAmely on March 30, 2010, 11:19:54 PM
D/P:

The 125 number is probably the kit number for all parts in a set. When the set was being assembled, someone must have borrowed a part (or the part was found to be defective) and the assembler took a part from the next kit to assemble this set. My theory and I am sticking to it.


Especially for field testing. Somewhere, someone is sitting on a ton of Field test documentation.

D/P

Copies of the field trial info probably reside in the personal files of the Bell lab engineers involved on the project.

I have a thick file of   early auto dialer info, (eBay) that came from the files of a bell labs engineer. These guys sometimes kept parts, models, and examples of some of their projects.

If you research the team members who designed the 500 set, locate them or their descendants, you may be able to talk them out of the files or maybe get some scans of the pertinent info.

There is a good chance the files were destroyed, sold on eBay, or perhaps, Donated to a local museum or historical society in or around Murray Hill, NJ.
I bet you could find a local historical society/musuem for Murray Hill, NJ by browsing the internet.

These files  would be a great go with.

Just a thought,
Jim

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

JorgeAmely

#309
Hi D/P:

In a large organization like Western Electric and Bell Laboratories, all phones assembled during development don't really needed to be fully functional units.

For example, the marketing people just want phones that look and feel like the real thing, because they are just interested in showing them to people to see how they like it. In these units they probably fitted non working parts (such as networks, etc).

Perhaps the Board of Directors was having a meeting and the shop provided them with some units to amuse and excite the investors. Mock-up units would be more than enough. The Mechanical department want phones with all parts in place to determine fit and placement with the purpose of determining if all parts mate properly, check for corrosion problems, whether they were finished properly so assemblers don't get cut while putting the unit together, etc. The Electrical department really doesn't care much about plastics and housing, they most likely want units will all electric parts inside to test them in laboratories for circuit properties, electric shock due to lightning, incorrect wiring and all kinds of things engineers do.

In an environment like this, it is possible that the industrial engineers decided to use the base number (125 for example) as the serial number of the set. A traveler document went through all assembly stages and employees just wrote down in the document the serial number assigned to each part as the set was being put together. At the end of the assembly line, the traveler document was filed so that if the unit came back with a defect, they can track the defective part to a specific lot and try to solve the problem with a supplier.

There are many ways companies elect to assemble products for production, and variations most likely will exist. Unless we have an insider from WE or Bell, we can only theorize what method was used to put this set together.

My 2 cents for today.

Jorge

paul-f

QuotePaul;
I have a couple quick items I would like clarified if you can.
In the first photo, what is the locked screw used for ? Is it an adjustment, or to hold internal parts in place ? I would assume all components were attached to the Black cover.

In the second and third photos, the number 125 appears on two separate components and you can see 124 on the ringer. What do these designate? I thought component numbers but two different components with the same number ?
there doesn't seem to be a definite pattern to the 3 digit numbers or the D177 numbers ?

I have no idea of the purpose of the locked screw on the equalizer, and agree with your observations and speculations.  I'm with Jorge -- the production sets I've seen don't have this feature.  I trust you're not about to open it up to find out, so we'll probably have to be content with guesses until someone finds the shop manual for this set!

My guess on the numbering is that the D- numbers are unique to the macro design of the component.  In past club discussions the D was speculated to stand for "Design" and related to a Bell System design specification.  The D- number on the bottom of a set typically related to the overall spec for the complete set, while the D- number on a component (e.g. ringer) related to the spec for that part.  If there was a major change to the design, the next one made to the new spec would get a new D- number.

Checking other sets on my site (http://www.paul-f.com/weproto.html) shows that sets in the 20s - 31 used Y- numbers, from 32 - 50s used D- numbers and in the 60s - 70s used F- numbers.  Some have speculated that the F stands for "Field Trial" but I know of no definitive source to confirm that.

An example of one set with different F- number versions is the 1960 Contour.  Another project is finding samples of both versions to document the differences -- but that's a discussion for another topic.

I believe the shorter numbers are simply serial numbers for components made to the marked specification.  As has been pointed out, we don't know the starting number -- whether 1, 10, 100, etc.  Each part would have a unique number, so its origin and history could be tracked during assembly, testing and use.

Therefore your ringer is uniquely identified for tracking purposes using the two codes, D-177006 and 124.

If the Bell System assigned numbers like engineering firms I worked for several decades later, there was a clerk who maintained the master number assignment list. When an engineer needed a code for a new part, a quick call to the clerk got the next available number on the list.  Unless there was a compelling reason, there was no master numbering plan to assign numbers based on the component's form or function.

The primary real purpose of the D- numbers may have been for the accountants to accumulate material and labor costs of each component during the development phase.

Since the short numbers do not match for all components within the set, it's logical to conclude that they were not intended to match.  The fact that several are 125 or 124 is just coincidence.  

I'm open to other speculations...

Paul
Visit: paul-f.com         WE  500  Design_Line

.

Jim Stettler

I like Paul's theory. Something I would like to add is that I think the D# parts were "trayed"

Field Trial sets were made in small quantities and I suspect the parts were laid out sequentially into trays.  The assembler grabbed a part and assembled it into the telephone. If the D#  parts were laid neatly in trays it would make sense that most of the control #'s of the sets pretty much matched.

as an example: If the "ringer guy" dropped #124, he grabbed #125 and installed it. then picked up ringer 124 and put it in the next phone.  The control #'s wouldn't matter much unless the part failed.

The components w/o d# were probably already tried and true. They just needed a control #.

On this set the D#'s seem to be on major parts that were unique to the 500 set.

Just some guesses,
Jim
You live, You learn,
You die, you forget it all.

JorgeAmely

#312
Quote from: paul-f on March 31, 2010, 01:08:47 AM

I have no idea of the purpose of the locked screw on the equalizer, and agree with your observations and speculations.  I'm with Jorge -- the production sets I've seen don't have this feature.  I trust you're not about to open it up to find out, so we'll probably have to be content with guesses until someone finds the shop manual for this set!


About the only way to see what is inside the equalizer is to use an X ray machine. Not available to everyone, but if you have a friendly dentist, it shouldn't be too difficult to X ray that box. Just say Aaaaaah  ;D

Dan from Ohio, any ideas  ??? ??? ???
Jorge

Dan/Panther

#313
Typically in my experience with a nut and screw in the center like that, You loosened the nut, adjusted the central screw to some specification, then re-lock the nut. But looking at a schematic of the EQ, The only thing I can think of is the screw was used to align the Thermistor bead, to the tungsten filament for maximum output of the Equalizer after assembling the EQ module. Later versions were modified to eliminate this problem maybe by the tube assembly. This version may have a separate filament and bead..
It would be similar to aligning the exciter bulb to the sound drum on a movie projector. Adjust the exciter bulb to maximum modulation without distortion of sound from the projectors amplifier, by aligning it to the sound drum.
If this is the case, once again it would in my mind points to an earlier version of the EQ.
D/P

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

Doug Rose

Hey Paul....welcome to the Forum. We are more than pleased to have you here. Your name is mentioned here often. You will not find a more passionate group in regard to telephones. This small group of collectors puts the previous lists I have been associated with to shame. Welcome aboard. Don't be a stranger, the forum needs your voice.....Doug Rose
Kidphone