I'm going to try a microwave oven xmfr but in a differant application,as a filament xmfr.:blink: I was thinking that if it had a secondary voltage of somewhere around 2000 volts with 120 on the primary what would the voltage be if one were to switch the primary and secondary windings around. IOW apply 120 volts to the normal HV winding. The result was with 120 volts applied to the high voltage winding the now secondary winding had a voltage of 6.2 volts, a tad low for 572B's. I am in the process of stripping turns off of the HV winding which is now the primary and hope to get about 6.4 volts or so.A little high is easier to deal with than a little low.The other good thing is that the HV winding (primary now) has one side tied to the case and is grounded.Since I plan to run the amp off of the 240 volt line it means I can derive the 120 volts by tapping one side of the hot 240 line and ground and not worry about a hot (AC) chassis or anything nasty like that. I'll let you know how it works out after I get the windings stripped.It's tricky going,not much space to start off with and my right thumb is not cooperating like it should. Ever try and tie your shoes without using your thumbs?
That's what I feel like.
As a side note,the oven xmfr is a good idea but the voltage would be far too high for 811A's,nearly 3000 volts with a capacitor input supply, unless it was rewound.