How to make an oscilloscope from an old TV

Do not try this unless you are a professional and know what you're doing. There is serious risk put on your life by opening up the back of a TV.

The TV is an old CRT television that uses 2 coils, a horizontal and vertical deflection coil to route the electrons to where they need to be on the screen.

By disconnecting these coils, and placing "dummy" coils in their place, you are allowed to apply current to them to make the electron beam fire where you want it.

The vertical deflection coil runs at a much higher frequency than the horizontal, so you'll get better results by using the horizontal deflection coil as your input. You can see the difference in the video.

Category:

Science & Technology

Tags:

• tv
• oscilloscope
• hack
• project
• diy
• visual
• wave
• crt
• instruction
• howto
• tutorial
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• cool
• electronics
• visual effect

[guitarslf132]

Are there multiple lines on the screen because there are more than one frequency in a song

[BackyardAmusement]

@guitarslf132 - No, I think it just happens so fast that it looks like multiple lines.

[nazaxprime]

0:24

/watch?v=HD5tnb2RBYg

;)

[BackyardAmusement]

@nazaxprime - makes no sense.

[hotamali]

@yuany25 you should always be weary of charged capacitors which can store high voltage in analog TVs

[yuany25]

how would it be dangerous..?? i mean if its not plugged in it should be alright??? right??

[cemx86]

1) The dummy coil fools the TV into thinking that the real coil is still attached. The real coil (on the neck of the picture tube) is then connected to the audio source.

2) To make the vertical line be a horizontal one, you can rotate the coil on the picture tube neck 90 degrees! There is a screw/strap that holds it in place, loosen it and rotate it, then tighten again. 3) One word of warning - the inside of this type of CRT TV has some EXTREMELY high voltages!! Be CAREFUL!!

[andythewooferguy]

what does the dummy coil do?

[memphisartguy2]

Wish i had found this before I did mine as I just jumped in to it. Here''s mine. Looks like we came up with the same thing. I added two switches and plugs that allows me change mode and return the to back to usable status. Capacitor in lime smooths it out, I did this as I remember when i was a kid all the speakers had them.

yP8ddiFJOU0

r2O8sy7bdB8

Fi8qOTg8MVg

H4JfnUg2dO4

[keoni29]

Never try to cut the brown wire with the thick isolation coming from the back of the tube. I,learned that the hard way :P

[DanielVidz]

Nice work mate!!

the horizontal deflection looks really good, is it possible to rotate 90 degrees like a laboratory CRO or would I need to use the vertical deflection coil with a freq multiplier?

[Psychentist]

Thumbs up if you watched the bee try to escape the spider web.

[melihsahcan]

zenith is proud with you :)

[braddo12345]

the reason why the solenoid was warm is because it needs a load to keep it cool. ie solenoid valve or screw driver.