WE 300B grid-plate curves from the 1950 datasheet
<a href="//commons.wikimedia.org/w/index.php?title=User:Retired_electrician&amp;action=edit&amp;redlink=1" class="new" title="User:Retired electrician (page does not exist)">Retired electrician</a>
<span class="int-own-work" lang="en">Own work</span> based as close as possible on the original <a rel="nofollow" class="external free" href="http://www.tubebooks.org/tubedata/Western_Electric_Vacuum_Tube_Data_1941.pdf">http://www.tubebooks.org/tubedata/Western_Electric_Vacuum_Tube_Data_1941.pdf</a> (the 300B sheets are actually dated 1-1-1950)