Re: Question Regarding XY Mode


Hi Siggi,

Okay - I read through that and it appears that I'm seeing the same results as others. Turning off CH1 will then allow the signal at CH1 to move the beam strictly horizontally (at least it does on my 2445 and I presume it will on the 2465B as well). Not sure I see that in the manuals though...

Barry - N4BUQ

----- Original Message -----
From: "Siggi" <siggi@...>
Sent: Monday, April 1, 2019 8:35:14 AM
Subject: Re: [TekScopes] Question Regarding XY Mode

Hey Barry,

IIRC, CH1 provides the X deflection in XY mode. You can then display any or
all of the e input channels under that X deflection, including CH1. This is
a little confusing, as you'll simply produce a diagonal line on the screen
(modulo X deflection bandwidth constraints).

There has surely been discussion of this before on the forum, see e.g.


On Mon, Apr 1, 2019 at 9:14 AM n4buq <n4buq@...> wrote:

I have, among other models, a 2465B and I have what I assume to is a
rather basic question regarding XY mode.

Placing the scope in XY mode and with an AC signal on CH1, with no other
channels set to display, I get a display pattern that appears to have both
X and Y components (e.g. a 45-degree moving beam). Without a signal on a
vertical input, I would have assumed that CH1's voltage would affect only
the X and without any vertical input, the beam would move only horizontally
but apparently that's not the case.

XY mode does work as I'd expect with signals on, say, CH1 and CH2, but
with only one signal on CH1, I didn't expect to see a vertical component.
Is there something about that setup that causes the scope to assume a
vertical value that's, maybe, equivalent to the horizontal component when
no vertical signal is supplied?

If this is outlined somewhere in the manuals, then I apologize in advance
and maybe someone can point me to that. From what I've found, though, XY
mode seems to be covered pretty lightly in the manuals I have.

Barry - N4BUQ

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