Yes you can replace the ZZ1000 [equivalent] neon reference tube in the 141T power supply with a zener. Although this solves the fuse blowing problem, the temperature coeficient of voltage of the power supplies [plural - because this is the reference voltage for 4 supply rails] is degraded, because zener diodes have a high TC at these voltages.. In practice you might not be bothered by this. I did this with my 141T, and it`s still doing just fine. Hoping this is of interest......................................................................................................................Don Collie ZL4GX
