28 A

28 A ; United American (ID = 1817533) Radio
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28 A ; United American (ID = 1817533) Radio
United American: 28 A [Radio] ID = 1817533 1154x2100
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For model 28 A, United American Bosch (Magneto Corporation); Springfield (MA):
German language newspaper ad from microfilm. 1928 Oct 18, Volksfreund, Appleton, WI page 5.
Country:  United States of America (USA)
Manufacturer / Brand:  United American Bosch (Magneto Corporation); Springfield (MA)
alternative name
American Bosch Magneto
Year: 1928 Category: Broadcast Receiver - or past WW2 Tuner
Valves / Tubes 8: 226 226 226 227 226 171 171 280
Main principle TRF (Tuned-Radio-Frequency but use of regeneration unknown); 2 AF stage(s)
Tuned circuits 3 AM circuit(s)
Wave bands Broadcast only (MW).
Power type and voltage Alternating Current supply (AC) / 110 Volt
Loudspeaker Electro Magnetic Dynamic LS (moving-coil with field excitation coil)
Power out
from Model: 28 A - United American Bosch Magneto
Material Wooden case
Shape Console with any shape - in general

One dial (primary tuning control knob) This set was also produced in Canada for Bosch and for Victor Talking Machines, LTD (V28). In some literature we found tubes 225 (which are only existing as Full-Wave Mercury-Vapor Rectifier from Kindermann) but this should be 226.

Price in first year of sale 170.00 $
External source of data Ernst Erb
Source of data Radio Collector`s Guide 1921-1932
Circuit diagram reference Radio College of Canada
Mentioned in RCC Bosch section page 4 and Victor section page 3.

All listed radios etc. from United American Bosch (Magneto Corporation); Springfield (MA)
Here you find 412 models, 158 with images and 269 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.