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25A7

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ID = 10709
       
Country:
United States of America (USA)
Brand: Common type USA tube/semicond.
Tube type:  HalfWave Rectifier-BeamPowerTetrode   Power/Output 
Identical to 25A7
Similar Tubes
Other shape (e.g. bulb type):
  25A7G ; 25A7GT
First Source (s)
23.Jun.1936 : Electron Tube Registration List
Predecessor Tubes 12A7  
Base Octal (Int.Octal, IO) K8A, USA 1935 (Codex=U)
Filament Vf 25 Volts / If 0.3 Ampere / Indirect / Specified current AC/DC ~ = (Series working)
Information source Taschenbuch zum Röhren-Codex 1948/49   
25a7.png
25A7: Courtesy Bureau Belper (De Muiderkring, Bussum), Scan Frank Philipse
Karel De Reus †
388.png 25A7: Telefunken Werkstattbuch
Wolfgang Bauer

Just Qvigstad
Usage in Models 3= 1935 ; 4= 1936?? ; 1= 1936 ; 2= 1937? ; 6= 1937 ; 5= 1938 ; 2= 1939?? ; 3= 1939 ; 1= 1940?? ; 1= 1940? ; 1= 1940
Quantity of Models at Radiomuseum.org with this tube (valve, valves, valvola, valvole, válvula, lampe):29
 
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