How To: Make A CRT TV Into an Oscilloscope

Step 2 Placing Wires

Desolder the vertical coil if you haven't already and attach extra wire to the vertical coil, this will have to be long enough to come out of the TV so you can attach a voltage source.
Now desolder the horizontal coil, and solder it to where the vertical coil was.

Comments

[bears0]

how can i tell polarity or does it not matter

[Magnelectrostatic]

The polarity doesn't matter. When the polarity is one way the electron beam is deflected up, when it's the other it's deflected down.

[bwandice]

This looks awsome, and I have been trying to get my '82 color tv to do this, but I think it might be too new to work. I have figured out which wires coming from the coil assembly are the vertical and which are horizontal. When I cut a vertical wire I saw a nice bright horizontal line, and vice-versa, so this made me think it would be able to work with this particular tv. So after cutting all the wires from motherboard to coil and after soldering the Horizontal wires from coil to where the vertical wires were on the main circuit board, I turn on the tv and there is neither a vertical or horizontal line at all! the Tv is just blank. Wat do?

[Magnelectrostatic]

Odd...Check the wires, if they're hooked up correctly try putting the wires back where they were before (vertical in vertical, horizontal in horizontal) to make sure nothing is broken, then try again, not really sure what to do other than that.

[Unit042]

So... this is essentially hijacking the vertical, while letting the TV circuit's vertical move the horizontal. I am currently working on an osciloscope that busted, I'm gonna hijack both horizontal and vertical coils, hopefully making it work again...

[Magnelectrostatic]

Good luck!

[Unit042]

Yes, indeed! My problem is multi-faceted. For the Y axis, I need amplification/de-amplification and positive/negative offset. For the X, I need a sawtooth oscillator, with a settable frequency, independantly controlled positive offset, upper and lower thresholds, and amplitude control. (And this is for one input. I am still figuring out how to show two inputs at once!) No worries, I have simulated a 555 and LM324 based circuit on Falstad's simulator. If you want, I can attach the saved file or post a screen shot of the schematic.