M
Mr.CRC
- Jan 1, 1970
- 0
Hi:
Recently at work I reviewed Tek MSO4000, Tek DPO7000, Agilent 9000, and
LeCroy MXi-A series oscilloscopes.
I have purchased recently an Agilent MSO7054B, Tek MSO4054, and LeCroy
104MXi-A.
The only one I regret purchasing is the Tek. I would have preferred to
have gotten their new MSO5000 model, but anyway...
The MSO4000 is my least favorite instrument, and will likely be a loaner
scope for giving to labs for temporary use, or for a new tech. that we
hope to hire soon. The reason is that it doesn't have the in-depth data
analysis of the LeCroy, and unlike the Agilent 6000 and 7000 series,
it's waveform update rate slows to a crawl whenever deep memory is used,
or measurements and digital channels are turned on.
The Agilent seems to be the best bang for the buck. I've had a MSO6054
for a few years, and now several of their 7000 series. They maintain
high update rates with the always-on deep memory (not quite as deep as
Tek, only 4MB when running Normal, 8MB with a single acquisition). The
Tek also tends to display persistence artifacts that make you think
something is there, but it's not, just persistence from the last acq.
So now the MSO7054 is my primary mixed signal design scope. The MSO6054
will be there for a student intern this summer.
You are probably wondering, well why the heck did I buy the Tek? I
needed a histogram measurement of some PLL jitter, and the Agilent can't
do that. I also mistakenly was still discounting LeCroy as not worthy
of consideration.
My feelings on the LeCroy changed due to the following endeavor: First,
another lab rat bought a LeCroy because it had more segments to it's
segmented memory acquisition than the Agilent. Also, the Agilent can't
maintain full sampling rate when more than a few 100 segments are
selected. Wierd. So he started selling me on the LeCroy, after defying
me and buying one after I tried to steer him toward Agilent.
Then I had a new measurement problem: Measure and optimize in real time
the shot-shot energy stability (relative standard deviation) of an
optical parametric oscillator, as a function of various parameters--you
don't want to know. OPOs are a bitch.
Well the Agilent and Tek can spit out numbers for standard deviation and
mean of an amplitude or area measure. Then I have to type them into my
calculator to get rel. std. dev. The Agilent accumulates N
acquisitions. The Tek has a moving average with configurable count, but
an unspecified weighting function that seems to lead to discrepancies
vs. the accumulating stats. on it's histograms.
Either of them can get the number with the assistance of a calculator,
but neither can give it directly in real time, nor provide a trend plot.
Enter the LeCroy. LeCroy loaned me a 1GHz 104MXi-A for over two weeks.
On the third day, I figured out how to make my measurement. The thing
can do trend plots of any measurement parameter, such as amplitude. You
can set how many past measurements to plot, so that controls the rate at
which it rolls across the screen, in conjunction with the acquisition
rate.
The you can compute mean and standard deviation (or any other maths) on
the trend plots, not just waveforms! That produces another numeric
measurement parameter output. That in turn can be put into another
trend plot! Magnificent. Then I can do a mean on that, with an
indicator bar. So I get three displays of my relative standard
deviation measurement: a number, a trend plot, and a graphical bar
indicating the average of the trend, sort of like a meter movement.
Sweet!
There is more than one way to set this up as well. It has this amazing
"web math" editor that is like LabView. It lets you graphically pipe
waveforms, parameters, etc. to measurements, math operations, and trend
plots, then pipe those to more, then output the results to measurement
parameter displays or math trace displays. That way, you can compute
operations on a virtual trend plot, without having to use a visible
trace, which are limited to only 8, I believe.
In short, the LeCroy is the best data analysis-oriented scope in the
under $20000 class.
The only drawback to the LeCroy is waveform update rate. It simply
can't come close to the Tek 4000, which also pales compared to the
Agilent (note: Tek DPO7000 is in another class altogether, with up to
250000 wfms/s vs. 100000 for Agilent, but only with 25k samples!).
Fortunately for my 10Hz laser pulses, this limitation of the LeCroy
won't be an issue.
The LeCroy also has these cool "track" plots which are different from
trend plots. Tracks are plots of the history of a measurement, time
correlated with the waveform being measured. So this can effectively
demodulate a PWM waveform, for ex., and plot the pulse width as a
function of time, correlated with the actual PWM waveform. Likewise for
other modulation schemes.
There are of course many other features in all of these instruments that
I haven't yet touched upon.
For general electronic design&troubleshooting, I will be turning first
to my Agilents. For tricky measurements with complicated math and
multiple stages of computation as well as trend plots, the LeCroy is
simply magical.
I don't think I'll be buying any more Teks unless there is something
that just can't be done with any other instrument. Unlikely.
I will have a look at Yokogawa next time I'm in the market though.
LeCroy is developed and made in USA, BTW.
Recently at work I reviewed Tek MSO4000, Tek DPO7000, Agilent 9000, and
LeCroy MXi-A series oscilloscopes.
I have purchased recently an Agilent MSO7054B, Tek MSO4054, and LeCroy
104MXi-A.
The only one I regret purchasing is the Tek. I would have preferred to
have gotten their new MSO5000 model, but anyway...
The MSO4000 is my least favorite instrument, and will likely be a loaner
scope for giving to labs for temporary use, or for a new tech. that we
hope to hire soon. The reason is that it doesn't have the in-depth data
analysis of the LeCroy, and unlike the Agilent 6000 and 7000 series,
it's waveform update rate slows to a crawl whenever deep memory is used,
or measurements and digital channels are turned on.
The Agilent seems to be the best bang for the buck. I've had a MSO6054
for a few years, and now several of their 7000 series. They maintain
high update rates with the always-on deep memory (not quite as deep as
Tek, only 4MB when running Normal, 8MB with a single acquisition). The
Tek also tends to display persistence artifacts that make you think
something is there, but it's not, just persistence from the last acq.
So now the MSO7054 is my primary mixed signal design scope. The MSO6054
will be there for a student intern this summer.
You are probably wondering, well why the heck did I buy the Tek? I
needed a histogram measurement of some PLL jitter, and the Agilent can't
do that. I also mistakenly was still discounting LeCroy as not worthy
of consideration.
My feelings on the LeCroy changed due to the following endeavor: First,
another lab rat bought a LeCroy because it had more segments to it's
segmented memory acquisition than the Agilent. Also, the Agilent can't
maintain full sampling rate when more than a few 100 segments are
selected. Wierd. So he started selling me on the LeCroy, after defying
me and buying one after I tried to steer him toward Agilent.
Then I had a new measurement problem: Measure and optimize in real time
the shot-shot energy stability (relative standard deviation) of an
optical parametric oscillator, as a function of various parameters--you
don't want to know. OPOs are a bitch.
Well the Agilent and Tek can spit out numbers for standard deviation and
mean of an amplitude or area measure. Then I have to type them into my
calculator to get rel. std. dev. The Agilent accumulates N
acquisitions. The Tek has a moving average with configurable count, but
an unspecified weighting function that seems to lead to discrepancies
vs. the accumulating stats. on it's histograms.
Either of them can get the number with the assistance of a calculator,
but neither can give it directly in real time, nor provide a trend plot.
Enter the LeCroy. LeCroy loaned me a 1GHz 104MXi-A for over two weeks.
On the third day, I figured out how to make my measurement. The thing
can do trend plots of any measurement parameter, such as amplitude. You
can set how many past measurements to plot, so that controls the rate at
which it rolls across the screen, in conjunction with the acquisition
rate.
The you can compute mean and standard deviation (or any other maths) on
the trend plots, not just waveforms! That produces another numeric
measurement parameter output. That in turn can be put into another
trend plot! Magnificent. Then I can do a mean on that, with an
indicator bar. So I get three displays of my relative standard
deviation measurement: a number, a trend plot, and a graphical bar
indicating the average of the trend, sort of like a meter movement.
Sweet!
There is more than one way to set this up as well. It has this amazing
"web math" editor that is like LabView. It lets you graphically pipe
waveforms, parameters, etc. to measurements, math operations, and trend
plots, then pipe those to more, then output the results to measurement
parameter displays or math trace displays. That way, you can compute
operations on a virtual trend plot, without having to use a visible
trace, which are limited to only 8, I believe.
In short, the LeCroy is the best data analysis-oriented scope in the
under $20000 class.
The only drawback to the LeCroy is waveform update rate. It simply
can't come close to the Tek 4000, which also pales compared to the
Agilent (note: Tek DPO7000 is in another class altogether, with up to
250000 wfms/s vs. 100000 for Agilent, but only with 25k samples!).
Fortunately for my 10Hz laser pulses, this limitation of the LeCroy
won't be an issue.
The LeCroy also has these cool "track" plots which are different from
trend plots. Tracks are plots of the history of a measurement, time
correlated with the waveform being measured. So this can effectively
demodulate a PWM waveform, for ex., and plot the pulse width as a
function of time, correlated with the actual PWM waveform. Likewise for
other modulation schemes.
There are of course many other features in all of these instruments that
I haven't yet touched upon.
For general electronic design&troubleshooting, I will be turning first
to my Agilents. For tricky measurements with complicated math and
multiple stages of computation as well as trend plots, the LeCroy is
simply magical.
I don't think I'll be buying any more Teks unless there is something
that just can't be done with any other instrument. Unlikely.
I will have a look at Yokogawa next time I'm in the market though.
LeCroy is developed and made in USA, BTW.