News:

"The phone is a remarkably complex, simple device,
and very rarely ever needs repairs, once you fix them." - Dan/Panther

Main Menu

Bell Telephone Manufacturing Cie model no 2725

Started by Matilo Telephones, February 14, 2015, 03:26:20 PM

Previous topic - Next topic

Matilo Telephones

Managed to get myself this model no 2718 by BTMC Antwerp.
I have been looking for one for quite a while, for a good price. Got this one for 15 euros (plus another phone for 15 euro, together 6,95 for shipping).

I do already have a Dutch built version of this telephone. I will be nice to compare them.

It is in good condition, although someone has been messing with the wiring. There is an extra green wire running from the top to the bottom of the ringer, function unknown at this point. And the diagram is missing.

It has the typical Belgian dial label, explaining how to operate the rotary dial. I love those.

It also has a decal with the words Teleautomate Bruxelles on it. It was a non-RTT phone, as can be seen from the blue lion stamps on the various components.
Groeten,

Arwin

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

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

wds

I always liked these wall phones.  I have one that is unmarked, not quite as nice as yours - how can I tell who made it?  On the inside of the back plate, next to the coil is stamped into the plate "8656    AP42579K"  Is this a clue as to who made it? 
Dave

unbeldi

#2
It seem to me that it has the same type of dial that my 1947 BT MGF Co  PS.28850 has.   See here: http://www.classicrotaryphones.com/forum/index.php?topic=8786.msg94761#msg94761

Mine is a 7019A.

The circuit is probably similar.  The induction coils looks identical, and the ringer construction is similar too, except the mine has the gongs mounted above the coils, more compact.
How many capacitors does it have?

Is there a catalog or resource somewhere that lists some of these model numbers?

Matilo Telephones

Thanks guys!

Dave, do you have pics of your phone? Perhaps there are clues as to where it was made.

Karl, your ringer is similar, but bigger.

For a good comparison of the 2 I have added the article Developments of subscriber sets from 1935, Electrical Communications.

It was written by an employee of BTMC. Very interesting article about the development of this telephone and its predecessors.

Here is a link to all volumes:

http://archivodigital.coit.es/index.php/mod.articulos/mem.revista/relcategoriarev.40459/relcategoria.1104
Groeten,

Arwin

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

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

unbeldi

I can't find your exact model number, but I am close with the 2725,  from a catalog dated 1932.

wds

yes - here's a couple. 
Dave

Matilo Telephones

Ah yes, I found that too. The model number is indeed 2725.

There is a BTMC catalogue from 1936 in the TCI library.

Dave, they were produced in Madrid and Buenos Aires too. Since your dial label is Spanish, I would think it would be one of them.

Where did you find it?
Groeten,

Arwin

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

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

wds

#7
I got it off of Ebay last fall - from Florida USA.   Yes, I see it in the catalogue now.  thanks!
Dave

unbeldi

So who developed this style of handset first?  Did BTMC copy it from S&H or the other way around?
I think it is a development that started at Siemens.

I have to find one of these for my BTMC.

Matilo Telephones

I do not quite understand that question? You mean the bakelite handset?

This particular model was developed by BTMC. Its predecessor for BTMC/Standard Electric phones was a copy of the E4 handset.
Groeten,

Arwin

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

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

unbeldi

Quote from: Matilo Telephones on February 15, 2015, 03:58:37 AM
I do not quite understand that question? You mean the bakelite handset?

This particular model was developed by BTMC. Its predecessor for BTMC/Standard Electric phones was a copy of the E4 handset.

Well, perhaps that wasn't clear indeed.
Telephone designers copied from each other everywhere.
This handset styling seems distinctively S&H, with the smoother overall lines rather than being composed of cylindrical shapes. The S&H W27 may have been the first. Ericsson still used cylindrical shapes in the 1931+ models. The WECo 302 was more or less a style copy of the DBH1001 series, albeit looking somewhat less elegant in the early dev types, ca.1931/2.
The BTMC handsets of the 20s also still are more or less cylindrical but the handle is getting a curve already, rather than being basically a straight tube. Fuld, I think, still had old shapes too into the 30s.
I haven't done a real thorough search of handset development in EU, the Siemens 27 comes to mind immediately.

unbeldi

#11
The anti-sidetone circuitry in these is identical to the Bell Labs AST circuits, which is not surprising as BTMC was a Western Electric sibling.

Here is the principle operating schematic of them. The induction coil values varied of course in Europe, because of different loop conditions and handset elements. This circuit was firmly established by 1930 and remained unaltered for the remainder of WECo's lifetime, only slightly adapted in the 500 set.