No's N2504, N2505, N2507, N2509 & N2510

Magneto Wall Telephones
n2505.jpg (19866 bytes) n2509.jpg (17518 bytes)
N2505, N2507 or N2508   N2509 or N2513

Robust and powerful instruments of the same design except that N2509 and N2510 (shown below) are fitted with the moulded Bakelite type of micro-telephone.

The casework is of polished oak with the external metal fittings finished black and copper bronze and the internal metal fittings, dull nickel plate.
All terminals are enclosed.
Polarised ringer, see table.
Powerful generator, see table.
Induction coil.

Battery compartment for 2 cells each having overall dimensions of 3.9 x 3.9 x 7.5 inches.

The wiring is so arranged that a condenser may be readily added in the ringer or receiver circuit as desired.

Micro-telephone N5801
Micro-telephone N5853
Micro-telephone cord N4024
Micro-telephone cord N4021
Mouthpiece N8625
"Inset" N7746
Earpiece N4441
Mouthpiece N8633
Receiver diaphragm N4401
Earpiece N4443
Diaphragm N4400

Code No.   Circuit description   Generator Magnets Ringer ohms Dimensions ins. Weight lbs.
N2504 Magneto, mining 16.5 x 10.5 x 10.5 18
N2505 Standard bridging 1000 16.5 x 10.5 x 10.5 18
N2507 Heavy bridging   2000 16.5 x 10.5 x 10.5 18.75
N2508 Magneto, railway 5 2000 16.5 x 10.5 x 10.5 18.75
N2509 Standard bridging 1000 16.5 x 10.5 x 10.5 18
N2510 Heavy bridging   2000 16.5 x 10.5 x 10.5 18.75
N2511 5 2500 16.5 x 10.5 x 10.5 16.25
N2512 6 2500 16.5 x 10.5 x 10.5 19
N2513 High Tension cct use 5 2000 16.5 x 10.5 x 10.5 17.25

For central battery signalling systems, instruments similar to the above but without generator can be supplied.

N2504 is a mining telephone that is only approved for surface use (pictured below).

N2508 has a push button on the front used for railway code signalling .

N2504 - N2510 introduced around 1932.  N2511 introduced around 1935.

N2510T had terminals mounted on ebonite.

Taken from the Ericsson Telephone Catalogue, edition No. 26, supplement 1932

Diagram N16143 is dated 1932.

N2504 - pre 1930's model N2504 - 1930's model

Click here for an article from the Ericsson Bulletin

Home page BT/GPO Telephones Ericsson Telephones Ericsson Home Page Ericsson PABX All Telephone Systems

Last revised: June 22, 2020