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ID = 8550
United States of America (USA)
Tube type:  Pentagrid-Converter (Heptode)   Pentagrid (old) 
Identical to 6A7S
Similar Tubes
Other shape (e.g. bulb type):

Base 7-Pin-Base U7A = small, old, USA (Codex=Mh) Top contact with a cap.
Filament Vf 6.3 Volts / If 0.3 Ampere / Indirect / Specified voltage AND current AC/DC
Description In 1941, RCA data sheet states "renewal type for Majestic receivers". the Majestic shield was is metallised paint. Replacement tubes also made by National Union, Raytheon and Sylvania utilised a sheet metal shield. 
Dimensions (WHD)
incl. pins / tip
x 118 x 34 mm / x 4.65 x 1.34 inch
Weight 41 g / 1.45 oz
Information source Taschenbuch zum Röhren-Codex 1948/49   
- - Manufacturers Literature   

491_4.png 6A7S: Datenblatt
Wolfgang Bauer

More ...

Just Qvigstad
6A7S: Manufacturer's Literature
Emilio Ciardiello

Usage in Models 1= 1932?? ; 2= 1933? ; 16= 1933 ; 2= 1934?? ; 24= 1934 ; 1= 1935? ; 3= 1935 ; 1= 1936?

Quantity of Models at with this tube (valve, valves, valvola, valvole, válvula, lampe):50

Collection of



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