Hey spec,
I am just as interested in getting to the bottom of this as you. Even more so as I want a working circuit !
So please feel free to nag me as much as you like.
There are pictures identifying the anode around on the net .. but I can't find one to hand at the moment.
How ever ..... there are 2 leads. one is in the middle ... that looking through my jewelers loop .. just seems to go right up the middle.
That wire
is the cathode.
The outer wire connects to to a grid that goes up the outside that
is .. the anode
.. the central wire is what gives off the electrons .. to ionise the neon.
BUT ..... If you put a high enough voltage on it .. I have seen the whole tube "reverse" ionise .. ie from anode to cathode. My video only partially shows this ... but when it does it you can clearly see that it is the outer "Grid" that is ionising.
Tell you what....
I will "dismantle" one.... (read smash it up) and post pictures.
Youtube video is at %50