My personal opinion of handheld Labscopes
By Michael McQueary
I remember my first experience with a scope, it was an old analog Tektronix that I picked up used at a scope shop a long long time ago. The first thing it helped me on was a Mopar dual pickup distributor. It would start, and then die. I hooked a channel to each of the pickups, and cranked it over to see what it would show me. I was surprised that nothing appeared at all! After getting the trace to show up on the screen by setting the proper scales, I was finally looking at my first real waveform on a scope. It showed me the start pickup was sending a signal, but the run pickup was dead. I replaced the assembly and the problem was corrected.
I was quite pleased with myself at this point, and I was
thinking of what else I could use this marvel of electronics
on for diagnostics. As it turned out, the old analog unit
wasn't good for much, because of its straight-line ability, I
used it less than my old Allen analyzer and even it had some
The main use of the scope is to measure time-based varying signals. Time, being one of the parameters for analyzing the waveform, the signal you obtain at a certain time period will vary. This variation is measured using the scope and the result is to find anomalies and anomalies and noises, along with the characteristics in it.
In my all my years as a Tech, I have seen many changes along the way, and I have tried to keep up with them. At times it seems like things change faster than you can learn them, but I think that most of us manage to keep up. It amazes me when I think back to the sixties and how simple things were then compared to what we are faced with today.
I have two of them, and I use them every day. They have the
power of the big machines, but take a fraction of the time to
hookup and look at something. Both of mine have a meter in
them for looking at the simple things we do most often like
voltages, amperage, ohms and so on. If you need to look at the
signals with more scrutiny, thatís where the scope shows its
ability. It allows you to see the signal over time and check
its structure and stability. It allows you to see the signal
at any speed you want, so you can look for intermittent loss
of the signal, transients, or plot it over a long period of
time. I am always finding new ways of using them that help me.
Don't get a false sense of security with these, I have
learned in my 46 years of experience that all the diagnostic
wonders in the world sometimes don't help beyond your gut
feeling, and when your not getting help, that's all you can
depend on, and more often it's right.