I am trying to decipher this circuit diagram here: http://tuopeek.com/lissajous.html

So far, I've been able to figure out that on the left are two signal generators, both connected to amplifiers and then to air cores. My question is: how do the air cores connect with the main circuit? And what exactly are air cores?

On the bottom are three SPST switches, all grounded. And there is a 'Heater'; possibly a volt heater? And what exactly are those?

And at the top right there is an EHT transformer. But there are two rectangles with arrows pointing through them that I cannot figure out.

Any help is appreciated.

Thanks,
chow_dairy

 

The Lissajous figures are by diplaying the X axis signal relative to the Y axis signal, hence the two inputs on the RH side shown at 90° to one another, air cores are inductors with no material ,ferrite, iron etc used in the core.
As shown, these are external scan coils on the neck of the tube or crt.
The heaters are shown as for three cathode emitters, this would only apply if a colour crt was used, red,green,blue guns.
The EHT unit, Extra High Voltage supplies the voltage for the focus and brilliance grids for the CRT as well as the final anode voltage .
Max.

 

Its a CRT, you need the heater to emit electrons these are attracted by the high voltage anode, usually 10 to 20Kvolts, as for the arrows they are variable voltages for focus, and brightness.

see CRT

 

BTW if this is just a modification to a TV to display Lissajous figures, you don't necessarily need a colour CRT, a B&W will work for simple unicolour display.
Max.

 

Thanks for the replies. This is my first time understanding a circuit diagram concerning CRTs, not really sure what comes with the CRT and what is added for just this experiment. Do the air cores usually come with a CRT in an average color TV?

The Lissajous figures are by diplaying the X axis signal relative to the Y axis signal, hence the two inputs on the RH side shown at 90° to one another
Max.

Did you mean the left hand side? I'm having trouble identifying the inputs. Are there symbols on the actual lamp that I am missing?

as for the arrows they are variable voltages for focus, and brightness.

Would it be safe to assume that this would be a place for potentiometers (among other places in the diagram)?

Thanks for the help so far, I think the best course of action right now is to open this sucker up and start tinkering (with respect to safety of course).

 

That should have read LH side! The coils shown are X & Y (Horiz & Vert) deflection coils mounted around the neck of the tube or CRT, right up against where the CRT bell starts to flare in shape.
Max.

 

the diagram is a little ambigous because its a generic tv diagram. showing how but not exactly how to modify a tv to act likie an osciloscope.

 

Yes, it is just a diagram on the principle, I assume you would set the grid and cathode bias to a preset voltage instead modulating it, and intercept the Horiz/Vert oscillators and feed in your X Y signal.
Max.