Tube question

[UnlikeKurt]

Hey everybody, a few quick questions regarding tubes ( i hope )

1. what makes a tube illuminate?
2. do all tubes light up?
3. has anyone ever designed a piece of gear where the tubes illuminate the controls?

thanks

[KennyLusk]

Hey everybody, a few quick questions regarding tubes ( i hope )

1. what makes a tube illuminate?
2. do all tubes light up?
3. has anyone ever designed a piece of gear where the tubes illuminate the controls?

thanks

1. voltage to the filament (turns into heat) and releases electrons to the plate. The heat causes the base of the filament to glow.
2. yes, all tubes "light up"
3. There's not really enough of a glow to illuminate much so I seriously doubt it. I could be wrong, but I'm not aware of any designs like that. Tubes are mostly hidden along with the rest of the components.

[RodC]

Check out nixie tubes, I use to work on some old Hemotology equipment that used them for displays. Not exactly iluminating the display, they are the display. They were used on the cover of the previous issue of TapeOp for the tape counter.

http://www.amug.org/~jthomas/clockpage.html

[UnlikeKurt]

Thanks guys
interesting info

[analoghacker]

1. what makes a tube illuminate?
2. do all tubes light up?
3. has anyone ever designed a piece of gear where the tubes illuminate the controls?

1) the "heater" in an indirectly heated cathode or the cathode filament in a directly heated cathode is the part that "illuminates". it glows because of a physical property known as luminescence. if there is any oxygen or other gases containing oxygen (like CO2) present in the sealed envelope, the heater/filament would burn (oxidize). like a light bulb, because the heater is enclosed in a vacuum, it becomes luminescent. of course, the main purpose in a vacuum tube is not to make light generally. it is to heat the cathode to a point where free electrons move with enough energy to reach "escape velocity" and become what we also call "emission". this charge can manipulated to do all sorts of electronic work.
2) all tubes "light up" but not all for the same reason. "cold cathode" tubes do not have heaters. they light because of the ionization of a gas, such as argon, mercury vapor, neon, or hydrogen. still other tubes are meant to light up in a particular way, such as cathode ray tubes, magic eye tubes, or "nixie" tubes. these are used for indicators and measurement.
3) take a look at the electro-harmonix NY-2A... or any old REVOX tape machine, like the B-36.

jc

[A-Barr]

Just to be totally obnoxious, I'll point out that light bulbs and CRT (cathode-ray *tube*) TV's are techinically all vacuum tubes and are frequently used to illuminate the controls.

Ah... love that tube warmth... try running an easy-bake oven with a new-fangled solid-state LED!

[r0ck1r0ck2]

HEY NIXIE TOOB WRISTWATCH!!!!!!!!!!!

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very nice