A local TV shop gave me a thermistor from a newer TV and I hooked it up in series with the degaussing coil. It did not work properly and magnetized the face of the tube. I need to manually degauss the face of the tube now.

I looked in the Digi-Key catalog and none of the negative temperature coefficient (NTC) thermistors had the right resistances or resistance ratios so I am looking in additional catalogs.

The Heath degaussing circuit has the NTC thermistor connected in parallel with the voltage dependant resistor and degaussing coil in series.