Figure 3.19. On the left is a 3 prong power plug. The bottom prong goes to the bottom end of the primary of a power transformer. The middle prong goes to chassis. This is the round ground prong of the plug. The upper prong goes to one end of a single pole single throw switch. The other end of the switch goes to a fuse. The other end of the fuse goes to the top of the transformer primary. The transformer has two secondaries. One is the 6.3 volt heater winding and the other is the high voltage winding which is center tapped. The H V winding is labeled 125 dash 0 dash 125 V. The 6.3 volt winding goes to the heater of the 6AQ5, and the heater of the 6AU6, pins 3 and 4 in both cases. One side of the heater is tied to the negative output terminal of the power supply. The upper end of the HV winding goes to the anode of a diode. The lower end of the HV winding goes to the anode of another diode. The cathodes of the two diodes are tied together and go to the positive end of a 22 u f 250 volt cap. The negative end goes to the center tap. The positive end of the 22 u f cap goes to the screen, pin 6, of the 6AQ5. Pin 6 goes through a 22 ohm resistor to the plate, pin 5. The cathode and suppressor are tied together inside the tube. The cathode, pins 2 and 7, goes to the positive output terminal. The positive end of the 22 u f cap goes through a 3.3 k ohm 1 watt resistor than another 3.3 k ohm 1 watt res to the anode pin 5 of the 0 eh 3 VR tube. There is a 10 u f 250 v cap connected from the junction of the two 3.3 k ohm resistors to the negative output terminal. The cathode of the 0 eh 3 goes to the negative output terminal. There is a jumper inside the 0 eh 3 connected between pins 3 and 7. It is intended to be wired to turn off the power if the tube is removed from its socket. The negative end of the 22 u f cap goes to pin 3. Pin 7, the other end of the jumper goes to the negative output terminal. Pin 5 of the 0 eh 3 goes to pins 7, cathode, and pin 2, suppressor grid, of the 6AU6. The screen grid, pin 6 goes to the junction of the two 3.3 k ohm resistors. The plate, pin 5, goes through a 1 k ohm res to the grid, pin 1, of the 6AQ5. The plate of the 6AU6 also goes through a 100 k ohm res to the positive output terminal, also the cathode of the 6AQ5. The positive output terminal goes through a 100 k ohm res to the top of a 100 k ohm pot. The bottom of the pot goes through a 200 k ohm res to the negative output terminal. The wiper of the pot goes to pin 1, grid, of the 6AU6. There is a 0.1 u f 400 volt cap from the positive output terminal to the grid of the 6AU6. End verbal description.
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