The hungarian field telephone 39 M. with buzzer only signalling is technically identical to the earlier 30 M. [1], but features a bakelite casing instead of a wooden one. It offers a straightforward design with easily replaceable components, ensuring simple maintenance and operation.
The specimen here presented is made by Telefongyar R.T., others were made eg. by Svéd és Társa [2]. There were an external magneto unit and a dial unit for the model 30 M., seemingly still used with the model 39 M [1]. The model 39 M. also adds a line control button (E "Ellenőrzés") [2].
Disassembled.
Electrical and wiring diagram.
"A HIVOGOMB(5) LENYOMA SÁVAL EGYIDEJULEG NYIT A (9) ÉRINTKEZO": "When pressing the buzzer button 5 also contact 9 is opened" (disconnecting the headset when buzzing).
The serial number 2173AD is a typical BTMC/Standard/ITT type of serial number.
The voice and buzzer coil.
Buzzer contacts, uncovered, to the right.
The buzzer ist not adjustable.
There is no wiring on the device, the coil/buzzer setup is gold by only 4 contact screws.
All other "wiring" is inlaid in the bakelite main board.
The buzzer contacts.
The buzzer protected by a small plastic hud.
To the right the patchcord socket, when a plug is put in the Line 1 side is disconnected from the device.
And to the right of that the surge protectors.
The battery compartment with the battery holder spring/lid put in.
There is space below the lid potentially could have been used to eg. carry a spare TX element.
The main board is marked with the manufacturer (This one made by Telefongyar R.T.)
Surge protector spares mounted to the Battery holder.
Seen from the top.
The buzzer lever, folded in.
The "E" (control button) is used to test the line.
"BEKÖTÉSNÉL EGYEZTESD A SARKITÁST A KÖZPONTTAL!": "When connecting coordinate the corner position with the centre".
I assume considering the fact that there is a empty socket hole which allows to connect the handset plug in a position where only the RX side is active.
V1, V2 are line and F the earth connector.
The socket Ö allows connecting a patchcord, when the patchcord is plugged the device is separated from the line, like this 2 lines on two devices could be patched through forming a very simple switchboard.
To the left of the "F" and the V2" there are the sockets for the headset.
Handset disassembled.
BTMS/Standard/ITT type handset form, and type of RX, TX elements.
The handset connection is a three wire setup using a three prong plug.
Ready to use.
Buzzer lever folded out.
The device includes an earth rod.
Handset stored in clamps inside top lid (on this specimen the clamps are broken on one side).
In the compartment to the right there would also be space for a headset.
Buzzer lever folded in.
Ready for transport.
The box has a fold out handle.
"VIGYAZZ! AZ ELLENSEG LEHALLGAT": "Beware! The enemy is listening."
Spelling table, most letters are represented by first names.
On the box side a holder for a strap and groves in the top lid to pass line and earth wires.
From the back.
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