Re: (Using Lab-Volt System) Have the books, how do I get a trace on my 465 Tektronix oscilloscope

Chris L (clusardi2k@xxxxxxx) writes:
Hello,

I already own the books "How to Use Oscilloscopes and Other Test
Equipment" by R. Penfold, "The XYZ's of Oscilloscopes" by Tektronix,
and "101 Ways to use your ... Oscilloscope" by R. Middleton.

How do I get something to show up on my scope?

I haven't used one in 10 years.

I set the channel 1 button, turned power on, hooked up correct lead to
a circuit board (Lav-Volt simulation of circuit where computer sim
told me to hook it up) from scope, hooked up a function generator
where the simulation told me to hook it up (sine wave, range 10X and
freq knob set to about 1) to circuit, tried focusing, tried
intensity, tried varying volt/div, and delay, but nothing would show
up.

How do I get something?

You're probably starting with too much complication.

With the sensitivity up, any scope will show 60Hz sort of sinewave
(50Hz if that's what you've got coming out of your AC sockets) when
you touch the probe.

What you didn't say is what kind of oscilliscope. IN the old
days, the average scope was pretty rudimentary, and it required
no skill to get some sort of display. But when they got
fancier, the triggered sweep often confuses people, because
they forget to set one of the often numerous switches, and
that causes a lack of display.

Focusing won't do anything. Given a trace, it will merely allow
you to get a narrow trace. But it won't cause the trace to
disappear.

Intensity can be a factor, because if it's set too low, you
won't get a display, and if the sweep is really fast, you may
need to turn up intensity to see the trace.

Positioning is a really important factor. There should be
knobs for moving the trace vertically and horizontally, I'm
not sure the exact labelling or even if there is standard
labelling. If the trace is off-screen, you may never realize
there is a trace. Fancier scopes will have a momentary switch
which compresses the display, so no matter how far off-screen
the trace is, you will see it and be able to get it centered.
Otherwise, setting the adjustments to more or less center
should get you soemthing which can then be perfected.

But, if there's no trace, none of that will help.

Delay is usually about adding some delay between a trigger and
the display. I can't see it being a factor here.

Usually the lack of trace is because one of the switches
for setting the sweep triggering is in the wrong position. If
it's in a single-shot mode, the trace will go from left to right
once, each time it receives a trigger voltage of suitable level.
If the level isn't right, you may not be triggering the sweep
and hence no trace.

Something like "auto" is usually a good mode to start with.

The fancier sweep modes, the more work you have to do with
all the controls, so if the sweep trigger switch is set
to the "wrong" position, you may have to fiddle with the
trigger level controls to get the thing to trigger.

Of course, there's always the possibility that the scope
isn't working. If it's new to you, that's always a possibility.
Even if you've had it around for ten years, there is always
the possibility that something has gone wrong in that
time.

Michael

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