866a tube Marconi Italy rectifier tubes for amplifier 211 gm70 845 3b28 866 300b 2a3

tube super strong emission tv7 tube tester results 58 & 58 ( reference good is 40 ) 

same emission for both tubes matched pair of rectifier 866a

yellow label made in Italy ultra rare to find

866a Marconi tube Made in Italy Ultra rare to find
tested super strong
cup getter
same yellow label on each tube
same Oldest production with oldest 866 Marconi logo 
ultra rare to find Made in Italy
oldest production strong long life

both tubes with Black base

866A = CE-866 = GU12 = RK866A = GL866A = VT-46A = DQ2 = RG3-250A = 2XM600A = P600_Mazda = AG866A = ML-866A = DR-866A = WL-866A
Similar tube:   38166A ; DCG3/1000E ; R3_Rectobulb
Other class quality:   866AX ; CV32
Other base:   866E
Multiple differences or of other kind:   3B28 ; DCG4/1000G ; DCX4/1000 ; R66 ; SS-866A

Socket  UX-Base 4 Pins 2 thick Top contact with a cap
Transmitter tube

Filament Heater    Vf 2.5 Volt / If 5 Ampere / Direct / Parallel, ~ = (AC/DC)
Work started on the development of this tube at the GE laboratories in the summer of 1932 and it was assigned the type number early in 1933. It was released to the public in April of that year.  

box 203