Neon sign + an -?

[kenw232]

I have an old neon sign.  I would like to hook it up to a high voltage circuit.  From what I understand there is a cathode and anode to these things.  How do I figure out which one is what?  There seems to be little letters on the sides but I don't think they mean anything.

Can someone tell me how to figure out which side of this tube gets the high voltage and which side is connect to ground/-?  Maybe using a multimeter?

[klugesmith]

As a rule, the tubes are electrically symmetrical.  Practically always connected to AC, low frequency or high frequency, with each electrode serving as a cold cathode half the time.
You could use DC but it's critical to have some kind of current limiting ballast.

Normally both sides of the AC are electrically "hot".  In low frequency transformers the center of high voltage winding is grounded.   An exception is some transformers at low end of voltage range (say 3 kV), used with short tubes, where one side of HV is grounded.