The third box on these phones was for the rather bulky early transmitter that Bell had standardised on, the Blake. American magnet technology lagged behind the Europeans, so their generators were larger. There simply was not enough room in the top box for a magneto generator and a bulky transmitter. The Blake was an adequate but not very good transmitter and it was eventually replaced in service by the Hunnings. For some time the Blake box was retained with the new transmitter mounted inside, before production eventually switched to the two-box design. Many will be found with an Ericsson upgrade transmitter replacing the Blake.
Left: Model 5722 with Hunnings-Delville transmitter. 1902 catalog.
Second: Model 5727 with extra earpiece and Hunnings-Delville, with the later model receiver. 1902 catalog.
Third: Original 3-box model with Blake transmitter. Model number unknown. This illustration from the 1902 catalog shows the later receiver, but most would have been fitted with the early receiver shown in the next picture.
Fourth: National Telephone Company pattern of 1893. Dual early receivers and Blake transmitter. From "Manual of Telephony", Preece and Stubbs, 1893.
Fifth: Model 5723with Solid Back transmitter fitted into a Blake box. 1902 catalog.
Bell Desk Phones
Bell 3-box Wall Phones
Western Electric Wall Phones
Early Bell & Western Electric Phones
Bell Wall Phones
Early Bell and Western Electric Phones
Consolidated Phones
History