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Resurecting an old VFD

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EDIT: Apologies, thread title should read "Resurrecting," sorry for the typo.

I recently acquired an old Vacuum Fluorescent Display that I've been trying to get working. (Part number PEDP0039, Futaba Electronics) Though I'm aware of the theory behind them (similar to a vacuum triode, but with multiple anodes that form the numbes), I haven't had any success in getting an element to light up.

The current setup:
A 9V battery powers a comparator-controlled boost converter circuit that charges a 150µF capacitor that acts as the HV power supply. The negative of the capacitor (call it ground for convenience) is connected to the filament, while the HV output (I've tried 30-70V) is connected to one of the segment terminals on the display. A 3V battery was connected across the cathode filament, to serve as the 'heater' supply.

I've read confusing information about the grid connections - some sources said to connect it to the HV supply, others said to bias it only slightly positive. I also tried leaving the grid unconnected. None of these configurations produced any light.

A picture is attached below of my (addmittedly rudimentary) circuit. (the 3V battery is not shown, but it was connected across the extreme left and right pins on the display)

Any ideas on what else to try in order to get some light?
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