Coronaphon (Corona-Phon) 2.1.2

• alternative name: Nederlandsche Radio Industrie

N.V. Idzerda-Radio model Coronaphon 2.1.2.

Coronaphon model 2.1.2 was manufactured from 1926 until 1930, however in different versions. Late models had a.o. a built-in loudspeaker and were housed in luxury cabinets.
The version without loudspeaker was manufactured from 1926-1828

Idzerda gave most parts and almost all radios manufactured in his workshop a unique serial number and noted these in a register, which has been preserved and is archived in a depot at Beeld & Geluid in Hilversum.
The radio in the uploaded photo has serial number 6191 and, according to the register, it was part of an order of 6 radio sets dated January 1928.

Note: the listed tube set may not be accurate.

In questo link sono elencati 67 modelli, di cui 30 con immagini e 9 con schemi.
Elenco delle radio e altri apparecchi della Idzerda-Radio, N.V., Fabriek van Radio-apparaten,