MH4 MARCONI ITALY TUBE PAIR preamp tubes MATCHED PAIR VALVE MESH kl70504 CURVED BASE OLD PRODUCTION 

2 TUBES MH4 MARCONI MADE IN ITALY BIG MESH PLATE , CURVED BASE BLACK , 

GLOBE BALLOON , MATCHED PAIR TESTED STRONG AVO VCM163 , 

TEST RESULTS AS PER  PICTURE LABELS , ULTRA RARE TUBES OLDEST PRODUCTION 

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)

BOX 128