aluminum foil on TV screen

They aren't designed for that and it seems like a stupid and dubious method. A Van de Graaf generator is not that hard to make

See

It's stressful on the internals of the TV

:)

That's the one, It probably has a high voltage charge (even when the TV has been unplugged for weeks) attach a screwdriver to the bare wires that cross the back of the TV using a convenient length of wire and probe around under that splotch until you hear all the charge has gone. under that splotch is a clip that'll unhook if you squeese it just right (use pliers).

no idea... I don't think there's any sort of chemical battery that can conveniently produce thousands of volts.

Bye. Jasen

As I said, I'm not planning to do this, at least not in the near future, and in any case I don't have a spare TV set to try it on. But I would like to understand a little better what you are saying needs to be done. By the bare wires that cross the back of the TV, do you mean those antenna leads or are you talking about something else? Actually, this gives me an excuse to actually look at a book on TV repair and/or a book specifically devoted to a particular model of TV. If there is a way I can get a complete schematic for free, accompanied by pictures of the corresponding parts of the assembled TV, I can refer to pin down details of what you are saying.

I've always been afraid of doing anything to cause the TV tube to implode, although I did take TV sets apart anyway. I vaguely recall cutting that cord on one or more occasions with a pair of pliers, without knowing that THAT was the locus that held high charges for a long time after the set is turned off. I don't think I realized that one can unhook the big splotch, but maybe I forgot after such a long time.

Anyway, apart from not knowing the site(s) you are referring to in the TV, I'm also having a little trouble parsing what you wrote: "... attach a screwdriver to the bare wires that cross the back of the TV using a convenient length of wire and probe around under that splotch is a clip that'll unhook if you squeese it just right ". I'm gravitating towards: (Step 1) attach a screwdriver to the bare wires that cross the back of the TV (Step 2) use a convenient length of wire to probe around (Step 3) under that splotch is a clip that'll unhook if you squeeze it just right

but I'm not sure. For example, maybe the convenient length of wire is instead supposed to be used to attach the screwdriver to the bare wires that cross the back of the TV. Also, with either interpretation, I'm not sure what the operation of probing around constitutes.

I don't know anything about batteries, but maybe they are referring to a storage battery or a collection of storage batteries, which one can just charge up from a wall socket. In combination, one might get to some high voltages.

there'll be some uninsulated wires that contact the back of the picture tube typically they're held in place with some springs etc. the outside and inside of the picture tube have conductive coatings and form a large capacitor.

That's pretty hard to do. The fragile part of the tube is at the pointy end. the rest of it it pretty tough, the front particularly so.

I've had to chuck rocks at the backs of TV tubes to bust them in the past. but I've let "the vaccum out" of tubes by just putting incorrect pressure on the circuit-bouard at the back.

sorry, I editied that paragraph too many times...

earth the screwdriver by attacing it to the bare wires, probe with the screwdriver till you hit the clip under the "sploth" thus making a path for the electric charge to take to dissipate safely.

The clip can then be undone safely if squeezed with pliers, but some charge will come back slowly (but much less than the normal charge)

hundereds of volts only, it sounds like you need thousands.

Bye. Jasen

That's interesting. Why did you want to break a TV tube? I once heard a lecture at a meeting of the AAPT wherein the speaker mentioned that he had broken a TV tube to obtain the phosphor coated glass for some kind of experimental demonstration. I don't remember what he was trying to demonstrate, though.

I haven't looked at the inside of a TV in over 20 years, so I might be hazy in my recollection. I don't remember any printed circuit board at the back of the tube. The closest thing I remember to anything at the back of the tube is the plug for the tube. But in any case, I'm curious about how much control one has over the change in pressure in the tube. If you let just a tiny amount of air in, maybe you'll then have a gas filled tube that you can try to do experiments in gas conduction with. If you put the TV in a big glovebox in an atmosphere of some gas, such as argon, maybe you can try to do the Franck-Hertz experiment with it. That's probably overly optimistic.

I've been discussing this on sci.chem and I'm still not sure about this point. For ionization of one of the atoms of the gas, presumably one needs 1-3eV per atom, but Gilardini is talking about electrons with typically 0.1 eV. So, if one needs thousands of volts to ionize a gas, maybe for his experiments one only needs hundreds. Also, if there is a tungsten filament in the tube, that makes it sound to me more like a gas filled tube, such as I find in the RCA tube manual requiring only hundreds of volts at the anode. But I really don't know.

I was a curious teenager, I chucked rocks around the corner of the garage until I met with success.

the intact front part of the screen was retained as "saucer" for a large pot-plant

that he had broken

I can't immagine. I think the phosphor oxidises fairly quickly.

These days there's a PCB soldered to the plug. it has the ampliifiers for the red green and blue drive

But in any case, I'm curious

It's kind of hard to see inside. most of the back is metal coated.

Even ion generators (running at normal air pressure) need over a thousand volts, you could get there (from ac mains) with a cockroft-walton voltage multiplier if you had enough stages in it. (not very safe though)