In the upper left corner a point labeled minus 300 volts connects through a 5 k ohm 10 watt res then a 100 volt 10 watt zener diode to ground. The cathode of the zener is grounded. The junction of the resistor and the zener is the minus 100 volt supply. The audio input couples through a capacitor, no value given, to the grid, pin 2 of a 12 A X 7. The grid goes to ground through a 470 k ohm res. The cathode, pin 3, goes to ground through a 3.3 k ohm res. The plate, pin 1, goes through a 270 k ohm res to point B. The plate also goes through a .01 mike cap to the grid, pin 7, of the other half of the 12 A X 7. This grid goes through a 470 k ohm res to point C. The cathode, pin 8, goes through a 10 k ohm res to point C. Point C goes through a 100 k ohm res to ground. The plate, pin 6, goes through a 100 k ohm res to point B. Point B goes through a 16 mike 350 volt cap to ground and also through a 22 k ohm res to plus 300 volts. The plate goes through a .1 mike cap to one grid, pin 7 of a 6CG7. Point C goes through another .1 mike cap to the other grid, pin 2, of the 6CG7. The cathode, pin 3 goes through a 2.7 k ohm res then another 2.7 k ohm res to ground. The junction of these two resistors goes through a 470 k ohm resistor to the grid, pin 3. The other cathode, pin 7, is wired exactly the same way with the 470 k ohm res going to the grid, pin 8. Each plate, pins 1 and 6, goes through its own 47 k ohm res to plus 300 volts. The plate, pin 1, goes through a .01 mike cap to the grid, pin 2, of a second 6CG7. The other plate, pin 6, of the first one goes to the grid, pin 7, of the second 6CG7. All that follows refers to the second 6CG7. The plates, pins 1 and 6, connect together and to plus 300 volts. There is a 470 k ohm resistor from each grid, pins 2 and 7, to the wiper of the bias set pot. The clockwise end goes to ground and the counter clockwise end goes to minus 100 volts. Each cathode, pins 3 and 8, goes through its own 4.7 k ohm 1 watt res to minus 100 volts. One of the cathodes, pin 8, connects directly to the grid, pin 5 of the lower 6146. The other cathode, pin 3, connects directly to the grid, pin 5 of the upper 6146. The cathodes, pins 1, 4, and 6, of both 6146s connect to ground. The two screen grids, pin 3, connect together and to a point labeled screen supply voltage. We will return to this in a moment. Each plate of each tube, top caps connects to each end of the modulation transformer. The center tap connects to plus 700 volts. The secondary connects to a load resistor 1700 ohms 100 watts. Now for the screen supply. The plate, pin 5 and screen grid, pin 6 of a 6AQ5 connect together and to plus 300 volts. The grid, pins 1 and 7, connects through a 100 k ohm resistor to the cathode, pin 2. The suppressor is internally connected to the cathode. The cathode goes to, and is, the screen supply voltage for the 6146s. The grid connects to the plate, pin5, of a 6AU6. The cathode, pin 7, and suppressor grid, pin 2, are grounded. A 100 k ohm res goes from plus 300 volts to the screen grid, pin 6, of the 6AU6. The screen grid also goes through a 51 k ohm res to ground. There is a .5 mike 100 volt cap from the screen to ground. The control grid goes to the wiper of a 100 k ohm pot the Modulator screen adjust. The clockwise end of the pot goes through a 47 k ohm res to minus 100 volts. The counter clockwise end goes through a 150 k ohm res to the screen supply point. End verbal description.
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