In figure C the input terminals are designated as driver plates. The upper input goes through a capacitor to the grid of the top output tube. This grid goes to a point labeled bias supply through a 100 k ohm res. The lower input similarly goes through a cap to the grid of the bottom tube and there is another 100 k res to the bias supply. The cathodes are tied together and go to ground. The screen grid of each tube connects to the plate of the same tube. The suppressor of each tube is tied to its cathode inside the tube. The plate of each tube goes to one end of the output transformer primary. The center tap goes to a point labeled plate supply. The secondary of the output transformer is not connected to anything in this drawing. In figure D the input terminals are designated as driver plates. The upper input goes through a capacitor to the grid of the top output tube. This grid goes to a point labeled bias supply through a 100 k ohm res. The lower input similarly goes through a cap to the grid of the bottom tube and there is another 100 k res to the bias supply. The cathodes are tied together and go to ground. The screen grid of the top tube goes to a tap on the output transformer primary which is about half way between the center tap and the top of the winding. The screen grid of the bottom tube goes to a tap on the output transformer primary which is about half way between the center tap and the bottom of the winding. The suppressor of each tube is tied to its cathode inside the tube. The plate of each tube goes to one end of the output transformer primary. The center tap goes to a point labeled plate supply. The secondary of the output transformer is not connected to anything in this drawing. End verbal description.
go back.