Schematic diagram of TRF receiver. The antenna coil has two windings. The bottom of the primary, black, is connected to earth and common ground. The upper end, white, is connected to an antenna. The bottom of the secondary, yellow, is grounded. The top end, green, connects to pin 1, grid, of the 6 B A 6 tube. One section of a two section 365 pf variable cap connects from the grid to ground. The heater, pins 3 and 4, goes to a source of 6.3 volts. The cathode, pin 7 goes to one end of a 3.3 k ohm resistor. The bottom end of the resistor goes through a 0.1 microfarad cap to ground. This is not a mistake. the cap goes to the bottom of the resistor not to the cathode. The junction of the 3.3 k and .01 goes to the wiper of a 100 k ohm pot, the R F gain control. The clockwise end of this pot is grounded and the other end goes through a 220 k ohm resistor to +150 volts. Pin 2, suppressor grid, of the 6 B A 6 goes to ground. Pin 6, screen grid, goes to +150 v. The plate, pin 5, goes to the primary, blue, of the R F interstage transformer. The other end of the primary, red, goes to +150 v. One side of the RF transformer secondary, yellow, is grounded. The other side, green, goes to the grid, pin 1, of the 6AU6. The other section of the variable capacitor connects from this grid to ground. The cathode, pin 7, of the 6AU6 connects through the parallel combination of a 15 k ohm resistor and a 10 microfarad cap to ground. The plus side of the cap goes to the cathode. The heater, pins 3 and 4 is connected in parallel with the heater of the 6 B A 6. The suppressor grid, pin 2 is grounded. The screen grid, pin 6, goes through a 1 microfarad 200 v cap to ground. A 62 k ohm resistor goes from the screen to +150 v. A 27 k ohm resistor goes from the screen to ground. The plate, pin 5, goes through a 150 k ohm resistor to +150 v. The plate also goes through a 100 pf 200 v cap to ground. The plate also goes through a .01 200 v cap to the output. Near the 6AU6 a .01 200 v cap goes from the +150 v line to ground. Near the 6 B A 6 another .01 200 v cap goes from the +150 v line to ground. End of verbal description.
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