You should be able to extend it a couple of feet at least (it's not *that* marginal!). There are no voltages higher than 12v on the cable, the 60v is generated on the display board itself. Remember this when handing it. Obviously your warranty will be void, etc.

The VFD doesn't get *that* warm! The filaments glow red (just about) but they are inside the glass :)

Hugo