b443 4 pin Valvola Radio Fotos tube valve finale radio res174d l416d pp415 pm24

1 valvola B443 4 pins (e contatto laterale) Radio Fotos Grammont La radio technique RT 

testata su prova valvole Funke W19S = 35mA (riferimento buona a 17,5mA)  no scritta a vetro,   

ricambio originale vintage per amplificatori e radio d'epoca a valvole vintage
ricambio originale vintage per amplificatori e radio d'epoca a valvole vintage

B443_4pin = L416D_4pin = W443_4pin = PP415_4pin = TU415_4pin = PM24 = B443A = RES174d = PT415 = R79 = 4GBF = RO4243 = T60_Adzam_4pin = TB43 = TL414 = 415QD_4pin = 415PP_4pin = 415PT_4pin = 410PT
Valvole simili  Sostituita normalmente - piccola diff.:   D100_4pin ; L43
Prime informazioni  Sep.1927 :
Zoccolo Europe 4-Pin B4 + side contact
Filamento Vf 4 Volt / If 0.15 Ampere / Direct / Specified voltage AC/DC

First output pentode on market September 1927
Equivalent types: RES174d (Telefunken), L415D (Valvo), PP415 (Tungsram)
Successors: B443S, L416D, RES164

The B443 is the first produced output pentode of the world, introduced by Philips in September 1927. It's amplification and its power output was much higher as with an output triode of equal size. The B443 has established the replacement of output triodes by multiple-grid output tubes. The equivalent Telefunken type RES174d appeared in 1931.


box 173