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TM-Metal

Sensibly equivalent to:
R. TM
See also:
Why the French R Valve - About the French TM Valve
    
Extras ▼

 

The Fotos TM was the original hard triode produced in France during WWI. When demand outstripped their capacity another lamp manufacturer, Compagnie Generale des Lamps, became involved, their trade mark was Metal and the valve TM Metal.
TM-Metal is an original valve whereas this has been repaired and the anode modified.
Thanks to Joe Gruber for sending the images.
The balloon envelope is 55 mm in diameter, and excluding the B4 base pins is 88 mm tall.
References: Data, 1047 & 1003. Type TM-Metal was first introduced in 1916. See also 1916 adverts.

 

Pin Connections
B4
1
2
3
4
a
g1
f
f

 

Absolute Maximum Operating Conditions
Triode
Vh
Ah
Va
4.0
0.65
120
Updated January 19, 2023.
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