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VT68_GPO

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ID = 32244
       
Country:
Great Britain (UK)
Brand: Marconi-Osram - (Valves/Tubes); GB
Developer: Marconi-Osram - (Valves/Tubes); GB 
Tube type:  Triode, vacuum   Power/Output 
  Ca. 1925 up to 1945 very rare. ***
Identical to VT68_GPO = CV1651 = G445B

Base Europe 4-Pin B4 (Eu A, E, 4A) 1914
Was used by Telephony
Filament Vf 4 Volts / If 0.45 Ampere / Direct / Specified voltage AC/DC
Description

The first VT68 was developed for the U.K.'s Post Office by Marconi-Osram as the G445B. This was a long life tube with a more robust and lower power filament than the LS(5B). The nickel ribbon filament operated at 1.8W compared with 4.2W for the LS type used in the line amplifiers.
The tube was subsequently incorporated in the CV1651 specification and was manufactured until about 1945 by other companies as the tubes were still required for telephony amplifiers.
The shape of the later tubes differs from the initial balloon shape of the early tubes.

 
Information source - - Manufacturers Literature   
The Saga of Marconi Osram Valve   Pages 136 & 137
 
vt68.jpg
VT68_GPO: RFJ
Roy Johnson

More ...
 
b4_1~~30.png
VT68_GPO: Fin Stewart
Fin Stewart

 

from Just Qvigstad

Collection of a member from D

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