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Re: Turn your Rigol DS1052E Oscilloscope into a 100MHz DS1102E


On Apr 8, 10:01A0%am, John Larkin
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When I am looking at video signals with higher power RF signals on the
board I will take an analog scope any day.

Re: Turn your Rigol DS1052E Oscilloscope into a 100MHz DS1102E


On Thu, 8 Apr 2010 08:57:53 -0700 (PDT), brent

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The advantages of single-shot acquisition, measurement cursors,
long-range pre/post-trigger storage, stored waveform pan and zoom,
waveform saving, signal averaging, variable/infinite persistance,
color, and shoebox size are overwhelming.

For HV/RF stuff, the TPS isolated-input scopes are radical. Clip your
scope ground lead anywhere.

John


Re: Turn your Rigol DS1052E Oscilloscope into a 100MHz DS1102E


On Apr 8, 12:13A0%pm, John Larkin
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Sure, in most cases I prefer a digital scope.  When they made the
digital scope user interface to mimic analog scopes interface (Why did
that take like 15 years???)
digital scopes are almost always better.  But for the stuff available
to me , I like analog scopes in the case mentioned above.  I do not
often come across that case.
Sometimes when I am trying to get a qualitative feel for thermal noise
in a receiver I prefer an analog scope too.

I have not tried the TPS isolated input scopes.  I hope to get a
chance to try one sometime (per your suggestion) , but our capital
budgets are severely limited these days.

Re: Turn your Rigol DS1052E Oscilloscope into a 100MHz DS1102E


On a sunny day (Thu, 8 Apr 2010 08:57:53 -0700 (PDT)) it happened brent

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beep BAD SYNTAX

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I agree, for video an analog scope is great.
In fact the *ONLY* reason for digital is storage,
and even then good analog storage scope once existed.
Storage is important when you look at one time events, long data sequences,
or events with a very low duty cycle that on an analog scope would show with
a too low intensity.
Those are, as far as I know, The ONLY advantages of digitising.
Maybe the FFT thing, and some other processing of data can be added as advantage
but that is actually no longer a scope.
Larking is a scope buyer, he seems to just buy and buy scopes,
not a real scope wizard.
I have re-scaled him to 3 on a 0-10 scale.

 

Re: Turn your Rigol DS1052E Oscilloscope into a 100MHz DS1102E



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I can think of a particular aspect of digital storage that, AFAIK, analog
storage can't do.  With digital storage, one can examine the signal BEFORE the
trigger point.  Has there ever been an analog storage scope that could do that?

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Re: Turn your Rigol DS1052E Oscilloscope into a 100MHz DS1102E


On a sunny day (8 Apr 2010 14:14:01 -0500) it happened The Phantom

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Yes, delay line.

Re: Turn your Rigol DS1052E Oscilloscope into a 100MHz DS1102E


On a sunny day (Thu, 08 Apr 2010 19:16:54 GMT) it happened Jan Panteltje

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PS
if you like analog scopes for video, maybe you will like this:
  http://panteltje.com/panteltje/scope_tv/index.html

The Z input!

Re: Turn your Rigol DS1052E Oscilloscope into a 100MHz DS1102E



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Your response is disingenuous.  You know that's not what I was alluding to.  The
delay line in analog scopes is just long enough to see the full extent of the
trigger event, and it's not a property of analog storage scopes alone; even
non-storage scopes have a short delay line.  Digital storage scopes, as you well
know, can see MUCH, MUCH further back in time than just a 20 nS delay line's
worth.

You said "Storage is important when you look at one time events, long data
sequences,  or events with a very low duty cycle that on an analog scope would
show with a too low intensity.

Those are, as far as I know, The ONLY advantages of digitising."

And, of course, those are not the ONLY advantages.  The ability to look back in
time far before the trigger event is a very great advantage.

Re: Turn your Rigol DS1052E Oscilloscope into a 100MHz DS1102E



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Sure.  Have you ever heard of delay lines?  Also, delaying timebases were
commonly used to look "before" the trigger event.  There are applications
where I'd still like a calibrated delayed timebase.

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advantage
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Re: Turn your Rigol DS1052E Oscilloscope into a 100MHz DS1102E


On Thu, 08 Apr 2010 17:36:30 -0500, " snipped-for-privacy@att.bizzzzzzzzzzzz" =

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You are right.  I have done things (been able to see things) with delayed=
 sweep20%
that i still cannot duplicate with a digital scope.  And that is with a =
mere 10020%
MHz bandwidth.

Digital scope manufacturers, you now have a well defined target to =
accomplish.

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Re: Turn your Rigol DS1052E Oscilloscope into a 100MHz DS1102E


On Thu, 08 Apr 2010 19:52:47 -0700,

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that?
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Delay lines can't store milliseconds of pre-trigger data. The best
they do is let you see a few ns of pre-trigger waveform.

John



Re: Turn your Rigol DS1052E Oscilloscope into a 100MHz DS1102E


On Thu, 08 Apr 2010 20:16:59 -0700, John Larkin

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the
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that?
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Enough to see what caused the trigger (and more than a few nS in some cases).
Yes, DSOs are useful tools.  I don't think anyone has said otherwise.  The
question was more about the utility of analog scopes, given that cheap DSOs
are available.  

Re: Turn your Rigol DS1052E Oscilloscope into a 100MHz DS1102E


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One case where a DSO comes in handy:
http://myweb.msoe.edu/williamstm/Images/Induction1203.jpg
something was clicking erratically, possibly a gate drive, I'm guessing it
stuck on for at most a few cycles.  Bad sign, and the clicking means
magnetics, or worse yet, sheer amperes, are causing audible movement of
wires or capacitors.  You can see a number of cycles on this exposure, where
current (bottom, triggered) is going wild, and you can see some voltage
steps where the coupling capacitor got charged by this action.  But without
a pretrigger on the order of microseconds, I can't very well see when it's
misbehaving.

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms



Re: Turn your Rigol DS1052E Oscilloscope into a 100MHz DS1102E



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I don't know who you think said that DSOs have no purpose, or are you into
strawmen today?

Re: Turn your Rigol DS1052E Oscilloscope into a 100MHz DS1102E


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John John John,

That's what entire spools of foamed teflon coax are for!  ;-)

Man, I can just imagine how many hours of cocaine you could buy for the
price of a few microseconds of that sort of stuff.  Seems kind of
disappointing.

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms



Re: Turn your Rigol DS1052E Oscilloscope into a 100MHz DS1102E



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So, let's see.  A moderate priced DSO, the Agilent 6000 series, can store 8
million points of data with a sample rate of 2 gigasamples/second.  If the
propagation speed through the cable is the speed of light (1 foot/ns), we would
need 4,000,000 feet of coax to do the job.  With a more realistic propagation
velocity, this is something like 500 miles of coax.  How many analog storage
scopes used this technique?

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Re: Turn your Rigol DS1052E Oscilloscope into a 100MHz DS1102E


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Dunno, probably none.  But notice my post concerned pre-trigger data (quote
retained above), which can be obtained for a short period (100s ns?) without
*too* much cable.

Trying to bring that into the storage domain would be difficult at least.
Even for hardline, HF loss on long lengths gets considerable, which suggests
zobel filters to correct it, weakening the signal and probably adding lots
of even harder to compensate group delay.  And this says nothing of trying
to regenerate the signal without distortion for more than a few cycles
through the line, something which can only be done consistently with an
ADC-buffer-DAC.  It is for this absurdity that I inserted a "wink" smiley,
which should be clearly visible.

Anyways, analog storage scopes used fancy CRTs, which allows a spacial
representation, much easier to maintain an image despite distortion.

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms



Re: Turn your Rigol DS1052E Oscilloscope into a 100MHz DS1102E


On Thu, 8 Apr 2010 22:26:29 -0500, "Tim Williams"

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It's hard to store much information in an electromagnetic delay line.
The losses kill you.

It would be an interesting calculation to see how many bits you could
store in any preferred length of, say, RG58.

Fiber is a different story. You can stuff gigabits per second into a
hundred kilometers of single-mode fiber and recover it perfectly.

But RAM is a more sensible way to store information.

We have a couple of spools, or rigid coils actually, of half-inch
hardline coax in our lab, 50 ns ballpark. They make handy zero-jitter
pretrigger delays for sampling scope situations. But the pulse that
comes out the end is clearly degraded from what goes in.

We also have a couple of Tek 7M11 delay-line plugins, which can be
used standalone. It's dual-channel, 75 ns per, 2 GHz bw. They give up
half the signal so that they can equalize for the losses.

John