UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Combined power-pentode and double-diodes?

G6Tanuki · 28th Nov 2022, 6:15 pm

The likes of the octal EBL31 [essentially an EL33 and two small-signal diodes] were popular in early poverty-superhets as an alternative to using a separate double-diode-triode [EBC33/6Q7] and less-high-slope output-valve [6V6 or something like a Cossor 42OT].

The idea seems to have been consigned to the history-books post-WWII; I have never come across a B8 or B9 glass-button-base equivalent of the double-diode-output-pentode.

Does anyone know different? I guess that after WWII there was greater wealth and the need for 3-valve-plus-rectifier poverty-superhets, along with the emergence of more modern valves made the idea of a power-tetrode/pentode with diodes obsolete.

28th Nov 2022, 6:15 pm	#1
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 14,007	Combined power-pentode and double-diodes? The likes of the octal EBL31 [essentially an EL33 and two small-signal diodes] were popular in early poverty-superhets as an alternative to using a separate double-diode-triode [EBC33/6Q7] and less-high-slope output-valve [6V6 or something like a Cossor 42OT]. The idea seems to have been consigned to the history-books post-WWII; I have never come across a B8 or B9 glass-button-base equivalent of the double-diode-output-pentode. Does anyone know different? I guess that after WWII there was greater wealth and the need for 3-valve-plus-rectifier poverty-superhets, along with the emergence of more modern valves made the idea of a power-tetrode/pentode with diodes obsolete. __________________ I'm the Operator of my Pocket Calculator. -Kraftwerk.