Unidentified Neon Tube
 

I have got a neon that if powered with AC via a resistor it lights up as a bar about 20mm long however if it is fed DC it glows for about 10mm of its length from one end and if you reverse it the other end glows.
I have no idea what it came off.

Split from this thread: https://www.vintage-radio.net/forum/...d.php?t=106341

Re: Unidentified Neon Tube
 

Sounds like an IN-24 http://tubehobby.com/show_det.php?det=49
As with any neon, AC will alternately light the anode and cathode. DC will only light one of them.

David

Re: Unidentified Neon Tube
 

It is not an IN-24 but another type that works on the same principal.
The ends are nothing like the ones on the IN-24 however it would be difficult to get the camera to focus down into the ends of the housing to see them.
There is no part number shown. It has the remains of a lens present at one end.
These could be used in early auto reverse tape recorders to indicate tape direction with suitable legend in front or anything else where a reversible supply could be used to drive it.
These are interesting components for sure.