British Field Telephone Identification.

[Chasemuseum]

Please assist with the identification of this model of buzzer type field telephone (no magneto), any information on when and why it was adopted and whether it was a general issue or a specialist type.

This example has some minor damage; -the vulcanite knob of the telegraph key is broken off, -one of the three brass wire loops to secure the leather cover is missing, -one of the leather tabs from the cover is missing and the leather case of the operator's earpiece is missing the short elastic strap with the buckle.

Functionally this appears to be very similar to the D Mk III buzzer type field telephone. It appears to take two "S" Inert or "X Mk II" dry cell 1.5V batteries. The wooden case is fitted with a brass base cap. The leather cover would have been much cheaper to produce than the type used with the D Mk III. I suspect that the phone would have been more robust in muddy set trench conditions than a D Mk III. The timber case is stamped "SIEMENS BROS & Co Ltd 425 F 1916 broad arrow" I presume that this indicates that it was nominally called the "F" Model and that 425 was a serial number.

The operator's earpiece is the standard model, common to the D Mk III. This example made by "STECO" and the case by "LEATHERIES LTD 1917". Steco was a major maker of telephone hand sets and ear pieces, probably the most common maker encountered on surviving examples.

The handset is not the "No 102" handset used with most models of field phones. This model handset is also used with the "Telephone Portable G". It does not telescope to be more compact for storage. The markings record the maker as Siemens Bothers & Company Limited (London) "F 982 1917" and patent number 5061/16. I presume that it is model "F" and that 982 is a serial number.

 

Panel is hinged to the left and rotates to allow access to the buzzer assembly. The battery compartment is below, accessed by it's own door in the wood case. There is no circuit wiring diagram and there is no indication one was ever fitted, however as the wiring diagram was typically only a paper label glued in place with a starch paste they could fall off easily. For many instruments they were covered in shellac to preserve them in service but this was a very inconsistent practice.

Detail for a wartime photo of an artillery signaler's training course.

Photo showing two of these field phones together with other signals equipment

 

Operator's earpiece in leather case, fitted with a two piece elastic headband

 

 

 

[Chasemuseum]

 

Above is a selection of a few of the different British field telephones of the Great War. I have labelled the phone I am seeking information on as a "D Mk III Variant F " 

If anyone has some information on it that can help with a better identification this would be greatly appreciated. Similarly with the identification of the press-to-talk type hand set connected to it. I have previously seen the same handset on a phone variant where the instruction label in the phone chest galled the phone a model "G".  Agaian I have never been able to find any information on the model "G".

 

[MaureenE]

Would any of the Manuals mentioned in the following link assist?

https://www.royalsignals.org.uk/line.html

On this page https://www.royalsignals.org.uk/signals.htm, No 5055 there is 

Instruction in Army Telegraphy and Telephony, Volume I - Instruments, 1916, WO2277.

If of interest the Main Page of the website https://www.royalsignals.org.uk tells how to request documents

Probably/possibly the same edition of  Instruction in Army Telegraphy and Telephony

Volume I-Instruments 40/WO/2277. Reprinted with corrections 1914, 1916 printing. Elsewhere, original edition stated to be 1908. HMSO Archive.org

(Volume II-Lines 1909, reprinted with corrections 1914 HMSO. Archive.org.)

 

Maureen

There is also an associated Forum https://groups.io/g/wireless-set-no19

Edited 9 April , 2023 by MaureenE