[Username1]

you know years ago I read an article about picture tubes with open filaments. I know some of you are going to poo poo the idea, and you know what you can do, but in I believe it was popular electronics, or radio electronics back in the late 70's when I was rich enough to get magazines. I remember a project for attempting to repair picture tubes with open filaments. If you had a tube with this condition and it was known to be good and worth it, what you would do was hook up yer VOM to the filaments and wack the neck of the tube, and if the needle moved, then it was thought that the filament wire was close to touching, and could possibly be "welded" back together. Now this only worked on B&W or other series filament color tubes. The project included testing the tube for the needle movement, and then if it were moving, the filament pins were then replaced with a charged capacitor, and then the tube was to be wacked again in a way known to always cause the meter needle to move when it was attached. The key was to get a pattern identified where the meter needle was guaranteed to move, that way you knew you could reproduce it and get a weld when the cap discharged when it was across the filament pins. Since I don't have the magazine, you would have to do some thinking, experimenting, praying, or other magic to figure out what cap and voltage charge might produce a good weld, and not burn off the wires inside the tube and make a second attempt pointless. Anyway since the person in this post has an otherwise useless tube, I thought this might be worth a try. Since I am older now, and many of you are smart enough to know about harmonics, here are some additional things to try to make this successful. If you can't get the meter to move with a simple whack, you may want to try adding harmonics to the parts inside the tube to ensure movement. Use a speaker and audio generator, mount the speaker to the tube, and have the sound vibrate the stuff in the tube. Put yer beeper, or cell phone on vibrate and let it vibrate against the tube. etc, etc on any things that can set up harmonics inside the tube's elements. it might also be a cool idea to try and see if you can see the open spot inside the tube before you begin... you know use a flashlight, magnifying glass, clean the neck see what might be available to see. Who knows you might even have to warm up the tube in the sun, whack it to see if you get a momentary continuity, maybe cool it, whatever might be needed to try and get a possible connection. And I'll tell you one more thing I did as a kid. We has clear light bulbs, and on a few occasions when I was less than 20 and with lots of time to learn and do weird stuff, a few times I took those bulbs when they went bad and could see the broken spot, shook the bulb moved it around and got the wire to slide out of the little round filament holders till I got the filament flappin in the unbreeze, and got it to lay across what was left of the other end of the filament still attached to the other post, and wa-la I had a bulb working again.... I carefully screwed them into a socket where I typically got another month or two out of them. Since they were brighter, I assume if I dimmed them a little I bet they would have lasted longer... Not really a concern welding a picture tube filament.