The Bad
It seems to have an inherent noise floor of perhaps +/- 3-6% on many signals, depending on the volts/div setting. This, combined with firmware bugs in virtually every single aspect of its operation, make for a somewhat dicey purchase. There are a lot of bugs. Pretty much every button and function seems to have at least one noticeable bug, and some measurements look off.
The highly touted "16KB/channel" buffer (really only 4KB in many modes) is useless, because one cannot navigate through it in a captured trace (see scrolling bugs below).
The unit I received has two hot pixels on the display, one of which is visible in the photograph above if you look hard enough (second grid from bottom, fourth grid from left).
The company (just three guys as far as I can tell), does release firmware updates every few months or so, but most of the bugs listed below have been around for at least the past year. So don't count on anything ever being fixed.
Eric Wittig is apparently responsible for some of the software. Michael Wittig (sales dude) and Thomas M. Wittig (hardware, firmware) did respond to a couple of my early emails, but nothing was fixed. They stopped conversing as soon as the 14-day return window slammed shut. Not that they might have honoured the return window anyway, or at least that's what other users have suggested (see the German discussion threads linked below).
And besides, numerous flaws and all, I'm keeping this scope. Returning it to Germany would be too risky/expensive for me.
Bugs Observed in Firmware Version 1.10.03 (25-March-2008):
The vertical grid lines are drawn incorrectly, showing 6 sub-divisions per division, rather than the intended 5 sub-divisions. This makes reading any kind of measurements from the display rather difficult, as most of us are not used to base-6 arithmetic.
Quick Meas voltage measurements do not appear to match the onscreen waveforms. This could be related to the base-6 arithmetic bug above.
Average Voltage appears to actually show average peak voltage, which is high by about another 3% (beyond the +/- 3% quoted accuracy) due to the inherent noise levels of the scope.
The horizontal zoom knob function is flaky when viewing captured traces. Sometimes it works, sometimes not.
When horizontal zoom does function (a rare event), it is usually only good for two or three zoom levels.
When using horizontal zoom, the display seems to jump scroll horizontally to a random point of the captured trace. This random point changes with each level of zoom.
The horizontal scroll knob often does not work at all on captured traces, making the 4KB/16KB trace buffers rather redundant.
When it does work, horizontal scrolling is way too slow to be usable.
The vertical zoom knob functions only when the scope is in continuous capture mode ("Run" mode). Captured traces can only be viewed at the vertical resolution from the time of capture. Zooming in/out is not possible at all.
The controls sometimes lock up and the scope stops capturing traces. Pressing either the Power button or the Auto-Scale button appears to be the only way to escape this mode.
The Run/Stop button normally shows green for Run, and red for Stop. But sometimes it shows green while stopped.
After exiting Quick Meas, the soft key menus still show Quick Meas menus. This happens for other functions, as well.
Power on zero drift. If you turn on the unit and observe the zero level, you may notice that it drifts quite a bit over time - probably due to the lack of thermal compensation.
Occasionally, the trigger will lose sync and you need to stop and start the capture again for it to re-acquire the trigger.
The video triggering doesn't work at all.
Many more minor bugs, not yet listed here.
The Ugly
There are several noticeable differences between claimed capabilities and actual implemented functionality. Someday, somebody is going to sue these folks into bankruptcy -- oh, wait, that already happened once, which could be why they changed the company name.
Missing Features that are Claimed to be Present:
The documented feature to trigger on individual video scan lines is missing from the product.
The Horizontal Roll function, described in the manual, is not implemented.
Missing advanced (aka. "useful") FFT functionality:
Pages 5-22 through 5-25 of the User's Guide describe a comprehensive set of FFT (Fast Fourier Transform) controls and menus. The illustrations there show menu entries for Span, Center, Preset, More FFT, Scale and Offset. Additional mention is made of interactions between FFT and the Quick Meas menus.
These imaginary functions/menus simply do not exist in the shipping product. The only FFT function in the product is a simple frequency overlay plot, which also slows the scope down to one screen refresh every 2-3 seconds or so. There are no scale/units labeled on the simple FFT plot, which makes it nearly 100% useless.
Poorly Implemented Controls:
When it works (not often), the horizontal scroll knob is too tiny, too clicky, and way too slow.
The vertical scroll knob is also too tiny, too clicky, and even slower than the poor horizontal knob.
The Quick Meas functions slow the screen refresh down to about 1/5 normal speed.
The useless FFT function slows the screen refresh down to about 1/30 normal speed.
The Probe Comp ouput contact is some kind of funky fragile gold plated recessed fitting, rather than the usual probe-friendly clippable tab. It is very difficult to hold the probe onto this signal while manipulating the scope controls. What were they thinking?
The vertical sensitivity/resolution is implemented as three ranges of three voltage levels each (with 1:1 probes, these are 5,2,1V, 500,200,100mV, and 50,20,10mV). A mechanical relay goes *click* when switching across ranges, presumably as a cost saving measure. The best accuracy and lowest noise is on the highest voltage level of each range (5V, 500mV, 50mV). The other levels within each range suffer from considerably higher noise levels.
The included probes are of very good quality. But there are no instructions on how to use the three separate adjustments on them.
Windows Software Application:
The scope includes a basic MS-Windows-only software application which communicates over USB. This application provides remote control of the scope from the PC, and can be used to print trace captures from the scope.
But just like the firmware, this application is also riddled with bugs. Live display viewing doesn't work for me here, so that ruins any concept of remote control. And printed screen captures do not have grid lines, which makes them similarly useless. Prints are also abruptly cut off at the page bottom for some reason.
The software randomly stops working at times, requiring the USB cable to be removed and reinserted to regain communications (or maybe that's just a general Windows thing).
KNOW AVAILABLE
1GSa/s Real-Time Sampling, 100MHz
4-Channel Digital Storage Oscilloscope
with VGA (640x480) COLOR Display
Automatic Measurements
Autoscale
Minor Mathematic Functions, no FFT
No Timebase Delay Function
Timebase 50ns/div to 5sec/div
Signal Refresh Rate
at timebase setting to 50ns/div:
Single Channel Operation
approx. 10 recordings/sec
Dual Channel Operation
approx. 5 recordings/sec
Three Channel Operation
approx. 3 recordings/sec
Four Channel Operation
approx. 2 recordings/sec
Time Base Accuracy ±0.5% at 5V/div, 500mV/div, 50mV/div
(no noise, perfect performance)
±5% at 2V/div, 1V/div, 200mV/div
100mV/div (some low noise)
±10% at 10mV/div and 20mV/div
(some noise)
Memory Depth 16k points/channel 50ns/div - 500ns/div
4k points/channel 10µs/div - 200ms/div
Does the company still exist?
This is similar to picking up a twenty years scope and complain about its obsolete specs. The statement is true, but not very useful to anyone.
Do you really consider it productive to criticize a scope that was already recognized as having major defects years ago? The open source project already acknowledged many defects, and tried to fix some.
This is similar to picking up a twenty years scope and complain about its obsolete specs. The statement is true, but not very useful to anyone.
I'm curious what those 4 QFPs were in the one picture, I couldn't read the writing on them.
Was this Welec / Wittig scope at least comparable to Velleman scopes? They had bandwith up to 30MHz or so.
It is pining for the fjords.
But but it's German
so it must be a very good product
ahh where am i from![]()
So long
Torsten
"Made in England"; "Designed in Germany"