Yesterday, 05:59 PM
Thanks Terry. After checking my notes I think I recorded about -10v at the 6A7 G4/control grid. The screen grid (G3 & G5) is about 67v. The cathode as noted is wired directly to the ground side of the heater filament for that tube, not to the #17 and 18 grid leak resistors. Those resistors are wired to the screen grid of the 78 tube. Does that sound right? The screen grid of 78 is also wired to the BC resistor #57 and sits at about -1.2v, which agrees with the later production schematic. #13 and #14 are tied together and in the circuit tied to the #18 resistor. My fixed cap looks to be original and is coded BlueBlueY which is 660,000 uuF or pF (schematic is 2250 pF). What seems to be not right at the SW oscillation is the wiring of the primary side. I seem to have one wire going to the switch (for position 3) and yet another wire coming in from the G2 grid of the 6A7 (@ about 120v), thereby by passing switch 1. Does that seem right? Does anyone think this alternate wiring scheme is OK or should I rewire back to orinial oem later production? Thanks..... Dan