radiomuseum.org
Please click your language flag. Bitte Sprachflagge klicken.

257A

Information - Help 
ID = 35223
       
Country:
United States of America (USA)
Brand: Western Electric Company Inc.; New York (NY)
Tube type:  Triode, vacuum   Universal 
Identical to 257A
Similar Tubes
Other base:
  231D

Base UX-Base (4 Pins (2 thick, USA 1924, UX) Top contact with a cap.
Filament Vf 3 Volts / If 0.06 Ampere / Direct / Battery =
Description Receiving triode, T8 bulb on four pin base plus grid cap. Mu = 8.5, Gm 0.38 to 0.56mS. 4000 hours life expectancy; controlled microphonics. Grid and filament spring supported by glass bead from top of plate. Developed for Northern Electric as variant of 231D.
Not to be confused with HK-257A/4E27 or with other transmitting tubes. 
Information source Tube Lore (I)   


Just Qvigstad
257a_1.png
257A: Manufacturer's Literature
Emilio Ciardiello

More ...
 
screenshot_20210911_083556_ebay.jpg

 

You reach this tube or valve page from a search after clicking the "tubes" tab or by clicking a tube on a radio model page. You will find thousands of tubes or valves with interesting links. You even can look up radio models with a certain tube line up. [rmxtube-en]
  
rmXorg