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Many of these gems were actually DELIBERATELY DESTROYED years ago because they were considered DANGEROUS. For those who don't know the background, pulse and rf supplies for high voltage were not developed until after the war. These pre-war sets used a second power transformer and usually a 2X2 rectifier with much larger filer capacitors to develop the 7.5kV second-anode voltage. These supplies were not energy-limited like the more modern flyback-pulse or rf oscillator supplies. These old supplies could easily continue producing high voltage at sufficient current to kill while loaded with body resistance. Body resistance normally presents such a heavy load on rf and flyback circuits to limit the output current to a level that will produce little more than a very unpleasant shock to a healthy adult. A picture tube only draws about 1mA of beam current from the hv supply. Pulse and rf supplies normally have high impedances which tend to limit their output current. I still wouldn't recommend touching the hv circuits of a flyback or rf supply with power on and also recommend discharging the filter capacitor(s) before working on them.
When restoring one of these pre-war gems, use extreme caution around the high-voltage supplies, never work near them with power applied and always discharge the filter before working on the hv circuitry.
John
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