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what make and model is this?

Started by mark9564, January 18, 2015, 12:03:21 PM

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unbeldi

Quote from: mark9564 on January 24, 2015, 10:10:43 AM
Automatic electric co. D68197A  1MF  LO

Another condenser? I see a silvery canned condenser next to it.
The fact that there are two condensers may mean this was wired as an anti-sidetone instrument, but that's not conclusive.
Hmm interesting, so where is the induction coil?  That will tell us how to wire it.

mark9564

Sorry that was the number on the silver can. Here is a picture of the condenser.

unbeldi

Quote from: mark9564 on January 24, 2015, 10:40:56 AM
Sorry that was the number on the silver can. Here is a picture of the condenser.
Ok, now it comes together...

This is the induction coil.  It is a NO. 20 coil.  This was the standard common battery induction coil before the No. 46 came out (ca. 1919).
Now we can start drawing a circuit diagram.

unbeldi

#18
Here is your solution.

The wiring diagram is adapted from a 1937 diagram as indicated, simplified and adapted for your case. The dial contacts are marked correspondingly, with the exception that your dial has an extra terminal not needed in this early type of phone. The dial is from the 1950s.  Therefore, you need to place a short jumper wire between terminals R and BB.

You need to trace the existing wires in your phone to make sure you understand their connections and rewire according to the diagram.  The colors in the diagram are in adaptation to the original Western Electric colors, but are different clearly in your case. In any case, they may help clarify the diagram flow.

You have a row of screw terminals on that connection block. You can use them any way convenient to make the proper connections. Take inventory of the wires and allocate them to a terminal as needed to connect to other wires, along the way note all terminal numbers directly on the diagram and keep for documentation.

The induction coil terminals may or may not be labeled, I am not sure.  In any case the terminals of the primary coil (1-2) are on one end block, and those for the secondary coil (3-4) are on the other end. You may be able to determine which end is which by where the existing wires are going. If not, the primary coil is the one with the lower resistance (~16 Ω) vs. the secondary (~27 Ω) if you have an ohmmeter to measure that.

mark9564

#19
That did it , I got it working!!
Thank you very much! :)


unbeldi

#21
I like your picture of the side of the No. 20 induction coil.  Thanks.  It shows clearly the old technology used in the 1910s.  The core is still made of soft iron wires, very nicely visible.  In 1918 or 19, Western Electric applied some several years of research into magnetic properties of metals to its production of induction coils by replacing the No. 20 coil with the No. 46 coil.  The No. 46 coil used a bunch of blades about 4 mm, perhaps a quarter inch, in width and same length of the coil. These were made from a specially formulated silicon-doped steel which had much higher magnetic permeability, meaning the generated magnetic field inside the core was higher in response to an applied voice current.  This means the coil was more efficient.

I think I have some pictures that show the same for the No. 46 coil...

Greg G.

Quote from: mark9564 on January 24, 2015, 12:47:50 PM
That did it , I got it working!!
Thank you very much! :)


Fun, ain't it?  You're done with that one, now go get more phones!  :)
The idea that a four-year degree is the only path to worthwhile knowledge is insane.
- Mike Row
e

unbeldi

Quote from: unbeldi on January 24, 2015, 01:51:08 PM
I like your picture of the side of the No. 20 induction coil.  Thanks.  It shows clearly the old technology used in the 1910s.  The core is still made of soft iron wires, very nicely visible.  In 1918 or 19, Western Electric applied some several years of research into magnetic properties of metals to its production of induction coils by replacing the No. 20 coil with the No. 46 coil.  The No. 46 coil used a bunch of blades about 4 mm in width and same length of the coil. These were made from a specially formulated silicon-doped steel which had much higher magnetic permeability, meaning the generated magnetic field inside the core was higher in response to an applied voice current.  The means the coil was more efficient.

I think I have some pictures that show the same for the No. 46 coil...

Here.
I made a comparison graphic.