MH4 MARCONI OSRAM GEC TUBE VALVE PAIR

2 TUBES = 2 VALVES = 2 PIECES = TWO VINTAGE VACUUM TUBES

MESH PLATE

TRIODE

GLOBAL SHAPE GLOBE BALLOON

SIDE GETTER MESH HOLED O SHAPE

OLDEST CURVED BASE

BLACK BASE

HIGH GAIN TUBE DRIVER FOR RE604 AD1 RS241

MH4 = A4110 = TL425 = TE24 = 70504 = REN904 = CV399 = VT139_GPO
Similar tube:   MH4 Catkin
Sub tube:   105 ; 41MHF ; 4GPAC ; A30D ; ACHL ; CV1037 ; D4 ; E438M ; HLA2 ; J15 ; J25 ; NR31 ; TE384
Heater different:   354V
Socket     Europe 5-Pin ( O5A B5)
Filament Heater Vf 4 Volt / If 1 Ampere / Indirect / Parallel, ~ = (AC/DC)

TESTED STRONG 14mA LIKE NEW , STRONG EMISSION TESTED

ultra rare to find in matched pair mesh plate globe balloon shape curved base oldest production 

BOX 66