Ericsson CD140
This Ericsson telephone is a model CD140 central battery telephone introduced in 1902, serial number 1269069 meaning it was manufactured in 1914.
This model was short lived, primarily because manual central battery switchboards were short lived. In fact, I am aware of only one such switchboard in operation in Finland, in Helsinki at Helsingin Puhelin yhdistys (Helsinki Telephone Association) now known as Elisa, from 1911 to 1922.
Whilst this phone looks like older wall phones, it is much smaller in size, under battery cover there are only capacitors and a transformer for the receiver and the area for generator is totally empty. The hook for handset is also unusually placed, in the centre of the phone.
This model was short lived, primarily because manual central battery switchboards were short lived. In fact, I am aware of only one such switchboard in operation in Finland, in Helsinki at Helsingin Puhelin yhdistys (Helsinki Telephone Association) now known as Elisa, from 1911 to 1922.
Whilst this phone looks like older wall phones, it is much smaller in size, under battery cover there are only capacitors and a transformer for the receiver and the area for generator is totally empty. The hook for handset is also unusually placed, in the centre of the phone.
When I bought this phone it had been modified by a phone company as a local battery phone: a lot of walnut wooden parts where missing and replaced by the parts made from birch, a generator had been added, large hole cut into the back board for the battery and a hook taken from some other model telephone had been installed.
Over the years, as a result of the phone having been very badly stored, the gluing opened the top were missing, the lacquer totally vanished and steel parts were severely rusted.
At this stage, I really did not know the extent of the job ahead of me !
Over the years, as a result of the phone having been very badly stored, the gluing opened the top were missing, the lacquer totally vanished and steel parts were severely rusted.
At this stage, I really did not know the extent of the job ahead of me !
This model telephone has several features, that other Ericsson models do not have:
*the bell motors and bell legs are screwed to wood grain painted steel plate;
* the handset hook is in centre of the phone and is very odd shape as can be seen from pictures;
* the switches that it controls are unique; and
* "battery cover" is made from wood grain painted steel and wood centre and has a lock at the bottom and can be removed totally.
*the bell motors and bell legs are screwed to wood grain painted steel plate;
* the handset hook is in centre of the phone and is very odd shape as can be seen from pictures;
* the switches that it controls are unique; and
* "battery cover" is made from wood grain painted steel and wood centre and has a lock at the bottom and can be removed totally.
I had to make the phone back cover from pine, a new "generator and battery cover" from walnut. (the front facing curvy wood was one of the hardest ones that I have ever made), a new top part to back board and the hole has been filled with new wood.
Making the missing metal parts was much easier even though making parts like the handset hook and the hook switch was quite tricky as, the switch only has 22 metal parts + 6 insulators.
Making the missing metal parts was much easier even though making parts like the handset hook and the hook switch was quite tricky as, the switch only has 22 metal parts + 6 insulators.
Here is the schematic for Ericsson central battery telephone taken from "Jauhiainen & Seppola Puhelin käsikirja" (Telephone handbook) from 1929.
All other wires are clear from schematic except the wires for extra receiver how should it be, parallel or series to the handset receiver, that I do not know !
All other wires are clear from schematic except the wires for extra receiver how should it be, parallel or series to the handset receiver, that I do not know !