In order to operate, nixie tubes need 170 VDC. I know that the mains voltage is 120 VAC-RMS. So if you account for the RMS value, 120*1.414 is nearly exactly 170 V. So would it be possible to make a full wave rectifier? I decided to simulate the circuit in spice. If I use a 500 uF capacitor and a 1M bleeder resistor, I get a constant line at 170 VDC. The ripple is ~0 V. My only concern is the stability of the components at such a high voltage. For example, I know diodes have breakdown voltage which apply to reverse current flow, but there may be other factors I'm not thinking of. And I'd also have to find capacitors capable of handing 170 V, although I dont think finding those should be hard.