With nostalgic smile I read the many mails about EF50 and other tubes that I
used in the "tube-times" of my ham-life.
Here some electrical data of it:
(source: Röhren-Taschen-Tabelle Franzis-Verlag München 1964)
The tube was used for HF- and wideband-amplification up to 50MHz. The
amplification could be regulated by varying the negative voltage at grid 3 -
says the book. This seems a little unbelievable to me, because mostly a
variable voltage at grid1 was used.
heater 6.3V - 0.3A / anode 250V 10mA / grid3 0..-54V / grid2 250V
3mA / grid1 -2V / resistor at cathode 600ohms.
socket loctal, comparable type EF53.
73 Walter DJ2LF
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