Overheating - melting the CRT neck

By means of a ribbon heating element softening the CRT glass, venting the CRT and analyzing what happens. Power source 12 Volts 100 Amps AC. later 18 Volts 130 Amps AC was used. The lowering of the current on the ammeter indicates the increase in resistance when the ribbon heater gets hot. In the later stages current is fluctuating a little as the ribbon heater shorts out between turns.