Antique radios, Old Time Radios

MT1_MOV

ID = 19708

Country:

Great Britain (UK)

Brand:	Marconi-Osram - (Valves/Tubes); GB
Developer:	Marconi's Wireless Telegraph Co. Ltd.
Tube type:	Transmitting Triode, air cooled Power/Output
	<1925 very rare. ***

Identical to

MT1_MOV = MT1_Ediswan

Similar Tubes

Heater different:

T250_MO

First year

Mar.1919 ?? British Radio Valves - The Vintage Years, Thrower page 129 (before = Ediswan)

First Source (s)

Mar.1919 : British Radio Valves - The Vintage Years, Thrower p.127

Base	Wires
Was used by	Transmittertube (Radio)
Filament	Vf 9 Volts / If 5.5 Ampere / Direct / Parallel, (AC/DC)
Description	Ediswan is probably producing until 1919 when production went to Osram. Fin Stewart lists MT1, MT3, MT4 and MT5 being produced by Osram (in "History of GEC and the Marconi Osram Valve", page 77.) First made by Osram lamp Works March 1919, before the MOV agreement was signed - 26/11/1919. Tube shown as made by MOV in the "Exhibit of Wireless Valves at the Exhibition of the Physical Society January 1920", page 12. Tyne and Thrower assign it to MOV. Similar to T-250, but for a lower filament voltage. The two tubes were interchangeable with each other, properly adjusting the voltage drop variable resistor used in series to the filament of each tube, as clearly shown in the application diagram below. By the way, it was common practice to etch the exact voltage value on the glass of each transmitting tube with tungsten filament, individually adjusting the series resistor. (Ref. 'Thermoionic Tubes' by John Scott-Taggart, 1921) Text in other languages (may differ)
Dimensions (WHD) incl. pins / tip	215 x 120 x mm / 8.46 x 4.72 x inch
Information source	Saga of the Vacuum Tube, Tyne p.381 - - Manufacturers Literature


	MT1_MOV: Ali e Onde, Franco Soresini Emilio Ciardiello

MT1_MOV: Banneitz, TB der drahtl. Teleph. 1927
Anonymous 15 Collector

Usage in Models

1= 1925 ; 1= 1927?

Quantity of Models at Radiomuseum.org with this tube (valve, valves, valvola, valvole, válvula, lampe):2

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