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.