Decided to use the scope itself as the 'dummy load' by plugging the psu
back into it. It now takes 1m 25s for the power resistor to reach 50'C
whereas previously it was just under 15s., so an unmistakable
improvement.
Does anyone know what temp I should expect this resistor to run at, BTW?
I mean if they're good for 70'C I could leave it powered up longer and
see if it tops out before reaching that.