DerStrom8
Super Moderator
Looking at your controls do you have Add selected in the vertical mode? If yes, turn add off and just use the X, Y mode.
Good catch Ron! I hadn't noticed that, it does look like it might be set to "add".
Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Looking at your controls do you have Add selected in the vertical mode? If yes, turn add off and just use the X, Y mode.
Looking at your controls do you have Add selected in the vertical mode? If yes, turn add off and just use the X, Y mode.
Also, as suggested, you will need to get a handle on Oscilloscope Basics so the scope is no longer like the controls of a space shuttle.
Ron
Wait a moment. Your post #9 with the X is showing me the signal sources going between a 0 degree phase shift and some degree of phase shift. What are the input signals doing back in your post #1? The diagonal line runs with the horizontal (X) and vertical (Y) input amplitudes. I don't think (operative word being think) it's a matter of the scope settings as much as a result of the input signals changing their phase relationships. I realize the frequencies are slightly different. I haven't a clue what Audacity tone outputs look like or how they generate left & right channel tones of different frequencies. I am just guessing what you are seeing is a function of the X,Y scope inputs and not caused by the scope. Not sure but that is my guess.
Ron
That was the first thing I thought of, that the signals weren't perfect. I've noticed a lot of tone generators actually loop, so the tone isn't pure. I'm wondering if the transition between the end of one cycle and the start of the next is throwing things off.
I wanted to be sure I didn't miss anything in the settings.
@ The OP: Once again, I suggest getting an actual signal/function generator and see if it looks any better. If it doesn't, it's something with the scope. But my main suspicion is that you're not getting a pure tone from Audacity.
I can tell you what is feeding this 'scope:
In audacity, I have two mono tracks, one with 1000hz sine, the other with 1001hz sine. The 1000hz sine has the balance slider pulled to the left only, and the 1001hz sine has the balance slider pulled to the right (as in the picture). Could it be that there is some other in-phase noise coming through on the silent channels of each track?
Thanks
I can tell you what is feeding this 'scope:
In audacity, I have two mono tracks, one with 1000hz sine, the other with 1001hz sine. The 1000hz sine has the balance slider pulled to the left only, and the 1001hz sine has the balance slider pulled to the right (as in the picture). Could it be that there is some other in-phase noise coming through on the silent channels of each track?
Thanks
You got me curious on this Audacity thing. OK, you are using Generate and selecting Tone, then what? I know the scope is displaying what it is seeing. That said we have Generate / Tone and are you selecting a Sine or Square wave? There are other options but I assume Sine and if not try selecting Sine.
Ron
Oops!I must ask, why the "disagree" on Ron's post? It was a perfectly reasonable question!
A straight line from bottom left to top right means you have the same signal on X and Y (assuming you haven't got invert signal selected ).
I suspect the problem is much simpler - when you select X-Y mode, do you not use either CH1 or CH2 as the X input? If it uses CH1 for X then this will give you the lissajous figure for the signal on the CH2 (the oval - CH1-X CH2-Y); but if you are still operating the scope in dual trace mode then you see the second figure - the diagonal line (CH1 -X CH1-Y).
i.e. if you're using one channel for X input, you can't use it as a 2nd Y input.
I think that MAB2 is on the right track.
Just bare with me while I ramble a bit here.
You have selected X-Y mode by turning the SEC/DIV control fully counter clock wise.
This makes Ch1 the X input for X-Y mode.
In the MODE area of the front panel, you have buttons for Ch1 Ch2 Ch3 and Ch4.
You have both Ch1 and Ch2 selected.
Try deselecting Ch1.
I think that this will give you the Lizzy figure without the diagonal line.
I think what is happening,
by selecting X-Y mode, the scope puts Ch1 on the X axis
by having Ch1 selected in MODE, CH1 is also on the Y axis
This is why you have the unwanted vertical line.
JimB
On the scale of a moldy crust of bread to full four course dinner, I think that this rates as a good bacon sandwich and a cup of tea!
Sounds like we have had some success here tonight.
I like success stories.
JimB