This Field-phone is not too easy to identify. Based on the parts and type of construction I date it between 1905 and 1915. The “C. Schaefer” company indicated on the label exists since 1889, it might be the manufacturer or dealer for the instrument. The company still exists but has no documentation that far back.
The instrument gives the impression of being of workshop and not industrial manufacturing.
I acquired it in the Grison region, so the burned in letters “EW. C” might indicate that it was owned by “Elektrizitätswerk Churwalden” (Power plant of Churwalden) which operated under that name from 1906 to the 50ies.
The instrument is equipped with a basic two winding induction coil, a 4 bar magneto and a 2x 750Ohm ringer mounted on a main wooden board and inserted into a wooden box. The handset is made of a steel frame with wooden handles, a PTT switch, a fix mounted 200 Ohm receiver with wooden earpiece and a modular transmitter pickup based on the “Lorenz” carbon transmitter format.
Pre-renovation
Ready to use
Ready, open (no batteries inserted)
Main board bottom, 2 winding coil, ringer, generator
Main board top, battery leads, bells, line connectors, lightning arrestors, pin to store crank handle
Handset disassembled
Wrong transmitter capsule (ZB = central battery instead of local battery, C.L. D.R.P. is probably C. Lorenz - Deutsche Reichspost) - Fix receiver 2x 100Ohm
C. Schaefer Fournitures électrotechniques en gros Zurich (Label inside lid)
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EW. C - probably EW Churwalden (Powerplant of Churwalden)
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All stowed
Ready for storage
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