French Army

Originally numbered in the TM (Télégraphie Militaire) series with the letters TM followed by the type number. There was also an ‘11’ series of all-metal construction with octal base and equivalent to comparable American types but using 11-volt heaters. Thus 11L6 was similar to 6L6 but using 11-volt heaters. Valves marked ECMR indicate French army origin (Établissement Centrale du Matériel Radio-télégraphique militaire.