Please click your language flag. Bitte Sprachflagge klicken.


Information - Help 
ID = 28625
Great Britain (UK)
Tube type:  Half-Wave Vacuum Rectifier   Power-supply 
  <1925 very rare. ***
Identical to U3 = AU3_E27
Similar Tubes
Normally replaceable-slightly different:

Base Edison big E27 = 27 mm Base on each end.
Filament Vf 5.5 Volts / If 1.5 Ampere / Direct / Battery =

Ua = 100 V, Ia = 37 mA; Uamax = 3000 Volt.
Upper base : single contact Bayonet 22mm. Lower base : Edison E27

Known Manufacturers are Osram and Cossor. Main picture shows the Cossor version. GEC Osram in additional photo.

Stokes shows a picture of an Osram U3 with a giant 4 pin base. However known Osram literature shows it with the Edison Screw base and is equivalent to the Cossor U3.

Text in other languages (may differ)
Dimensions (WHD)
incl. pins / tip
56 x 130 x mm / 2.20 x 5.12 x inch
Weight 50 g / 1.76 oz
Tube prices 2 Tube prices (visible for members only)
Information source 70 Years of Radiotubes and V.   
- - Manufacturers Literature   1924
U3: Fin Stewart collection
Fin Stewart

U3: Banneitz, TB der drahtl. Teleph. 1927
Anonymous 15 Collector

from Just Qvigstad

Collection of a member from D

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]