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  1. Sure, if that "other potential" has very low AC...

    Sure, if that "other potential" has very low AC impedance to ground, meaning that it actually IS an AC ground.
  2. Black schematic shows (DC) elevated AC heater...

    Black schematic shows (DC) elevated AC heater supply. Of course DC heaters could be elevated as well if required for the reasons described by nickb (cathode followers etc.).
  3. I think that even with DC heaters it is advisable...

    I think that even with DC heaters it is advisable to ground some point of the heater supply. Reason is that while there is no ACV across the heater filaments, the whole heater supply will have some...
  4. The "red" schematic shows DC preamps heaters,...

    The "red" schematic shows DC preamps heaters, probably floating and not elevated - but depends on rest of circuit.

    The "black" schematic shows elevated AC heaters.

    Both methods help to minimize...
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    Testing one winding is enough as all windings are...

    Testing one winding is enough as all windings are coupled and if there is a short in any winding it will prevent high flyback voltage in all windings.

    58667

    Other than described in the text the...
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    I do. Must be an internal winding short. ...

    I do. Must be an internal winding short.



    Seems the step-up ratio of the PT of around 5 was high enough to just ignite the neon. I found considerable variation of neon ignition voltages. Some...
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    Low reflected primary impedance means low voltage...

    Low reflected primary impedance means low voltage drop in series with the bulb. I have no doubt that there must be either an internal or external PT short.
  8. With typical Fender coil dimensions you should be...

    With typical Fender coil dimensions you should be getting around 7k. You might have some shorted turns. Meter battery good?

    Magnets have no influence on DCR.
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    Well, thinking about it, that's actually no...

    Well, thinking about it, that's actually no surprise on the bulb limiter (representing a relatively high series resistance). An internal or external short means a load to the winding concerned. As...
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    Exactly that were my motives. Couldn't have...

    Exactly that were my motives. Couldn't have phrased it better myself.
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    Are you sure you disconnected all secondary wires...

    Are you sure you disconnected all secondary wires including the heater windings (total of 12 wires)? What is your bulb wattage?
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    To make sure, you can do an additional test: With...

    To make sure, you can do an additional test: With ALL secondary wires disconnected and on the bulb limiter, measure primary and secondary voltages and see if voltage ratios are correct or not.
  13. Means around 15W or 60% plate dissipation. Should...

    Means around 15W or 60% plate dissipation. Should be fine.
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    PT might have a short between the HV winding and...

    PT might have a short between the HV winding and core/ground. Measure DCR between CT and chassis.
  15. THe schematic shows 1.2R (not 1.0R) cathode...

    THe schematic shows 1.2R (not 1.0R) cathode resistors. So 35mV corresponds to only 29mA cathode current.
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    This table specifies 7A max for chassis wiring:...

    This table specifies 7A max for chassis wiring: https://www.powerstream.com/Wire_Size.htm
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    I don't think we disagree on the topic either and...

    I don't think we disagree on the topic either and am sure it is in the best hands with you.
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    There is a possibility that the person who...

    There is a possibility that the person who installed the switch, reversed the OT primary leads on the switch, which might give rise to high current draw in pentode mode caused by oscillation....
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    My comments were solely cap measurement/meter...

    My comments were solely cap measurement/meter (not fuzz issue) related. I wouldn't suggest to replace caps without clear indication.
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    But we have two caps self-heating.

    But we have two caps self-heating.
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    That's not normal. Check for correct ecap...

    That's not normal. Check for correct ecap polarity. Wrong polarity can damage the cap.

    Your out-of-circuit cap/ESR measurements all look good (old and new caps). In-circuit measurements are always...
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    Yes, that's what I originally bought them for....

    Yes, that's what I originally bought them for. But with high speaker currents I wouldn't want to rely on some press fit grounding.
    So they are useless.
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    I can confirm that the 2 RCS plugs have NO...

    I can confirm that the 2 RCS plugs have NO solderable ground lugs/tabs (at least the two I once bought). The body is a single massive piece of metal (probably nickel plated cast zinc). It doesn't...
  24. Looks as if the author is a certain T(im)Robbins...

    Looks as if the author is a certain T(im)Robbins :)
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    Peak PI output is actually less than 1/4 HT.

    Peak PI output is actually less than 1/4 HT.
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    Pictures? I'd start with warm soapy water on a...

    Pictures?

    I'd start with warm soapy water on a cloth.
    If that's not enough use some oil (or WD-40) on a cloth (after drying) and (carefully) follow up with naphta or white spirit - or soapy water...
  27. "Panning" between out of phase signal versions...

    "Panning" between out of phase signal versions produces phase modulation. And phase modulation always means frequency modulation as well. The frequency shift is proportional to the rate of phase...
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    Yes, but the OP's question was about leakage. And...

    Yes, but the OP's question was about leakage. And only the leakage test requires high voltage (could be taken from the amp).
    The importance of real cap value (as opposed to DMM cap measurement) and...
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