The sign’s other defining trait boils down to one word: neon. Glass tubes filled with the colorless, odorless noble gas illuminate its red letters. Several neon enthusiasts, including Jim Rizzo ...

The core of this build are a few tiny NE-2 neon bulbs. These are the same type ... giving [castvee] a real seven-segment display, a plus or minus sign, and an equals sign. It’s the beginnings ...