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Re: Digital Oscilloscopes



Yes, the 1S2 500 series plug in. A pain because they used a neg-resistance
diode (forgot the name) that were always blowing. A cute way of increasing the
speed of the 'scope, but require a repetitive signal.

bc who thinks he has one in his garage (and most likely is "inoperative.")

P.s. Esaki diode


Chris Horton wrote:

The "Sampling Oscilloscope", which samples at a selected rate and builds up
an image of a waveform which is itself too high in frequency for a
conventional 'scope' to display, predates the "digital scope". Whether all
digital scopes are also sampling scopes I don't know, but it seems logical
that they would be.

The first sampling scopes were analog devices which produced a dot on the
CRT screen proportional to the potential of the signal at the moment of
sampling. If the sweep time were right successive samplings would be
successively later (or earlier) in the signal cycle, and the signal form
would thus be revealed on the screen.

Clearly a sampling scope is collecting data in digitizable form. One would
add a timer and fast multichannel analyzer to categorize each impulse by its
time of occurance and potential, and a microprocessor and storage medium to
store, retrieve and display this information appropriately.

Chris Horton

----- Original Message -----
From: Ludwik Kowalski <kowalskiL@MAIL.MONTCLAIR.EDU>
To: <PHYS-L@lists.nau.edu>
Sent: Sunday, May 19, 2002 10:13 PM
Subject: Re: Digital Oscilloscopes

I learned today that the concept of "sweeping time" (period
during which the signal is being displayed in an analog
scope) does not apply to digital scopes. The corresponding
concept is "sampling" which keeps going continuously at
a selected rate. I also learned that, as confirmed by Brian,
a "record" is a set of data points from which a single
shape is constructed on the screen, or saved as a file for
possible future examinations.

But the concept of two triggering time bases (each with
its own selectable delay) is still a mystery to me. Perhaps
I will learn about this in "Digital Storage Oscilloscopes,"
the 1997 book by Jan Hickman.

While "fishing" over the Internet I found some useful
tutorials, for example, at:

http://www.cs.tcd.ie/courses/baict/bac/jf/labs/scope/oscilloscope.html
and
http://www.lecroy.com/Tutorials/Fundamentals/fund.html

Perhaps somebody else will find these tutorials worth reading.
Ludwik Kowalski