Please click your language flag. Bitte Sprachflagge klicken.


Information - Help 
ID = 28718
Great Britain (UK)
Tube type:  Triode, vacuum   Universal 
Identical to R_Marconi = TM
Similar Tubes
Other shape (e.g. bulb type):
Normally replaceable-slightly different:
  ES4 ; RA_Mullard
Other class quality (otherwise equal):
First year 1922 Saga of the Vacuum Tube, Tyne page 380
Predecessor Tubes TM  
Successor Tubes 1925   R5V  

Base Europe 4-Pin B4 (Eu A, E, 4A) 1914
Was used by Radio/TV-reception etc.
Filament Vf 4 Volts / If 0.7 Ampere / Direct / Battery =

British version of the French TM of 1916. Tubes originally branded
Marconi's Wireless Telegraph Co. From the formation of the M O V co Ltd in 1919, the brand was changed to Marconi Osram. Tipless bakelite base versions of the tube were made from late 1925

Dimensions (WHD)
incl. pins / tip
x 118 x 55 mm / x 4.65 x 2.17 inch
Weight 52 g / 1.83 oz
Tube prices 8 Tube prices (visible for members only)
Information source Saga of the Vacuum Tube, Tyne   1925 Brown Brothers Catalog 217
The Saga of Marconi Osram Valve   20 page references
Geri Meier

More ...
R_Marconi: rtt
Anonymous 10 Collector


from Just Qvigstad

Usage in Models 2= 1920? ; 7= 1922 ; 3= 1923

Quantity of Models at with this tube (valve, valves, valvola, valvole, válvula, lampe):12

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]