Author Topic: Welec W2000A - Worst oscilloscope ever??  (Read 18084 times)

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Offline Hydrawerk

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Welec W2000A - Worst oscilloscope ever??
« on: June 10, 2013, 09:38:39 am »
Hey, folks, please, what's this oscilloscope like? According to the web http://www.welec.de/english/01_company/company_01_profile.htm the Welec W2000A oscilloscope was introduced in 2007. It looks like a quite crap scope... It's front panel is apparently inspired by Agilent DSO6000 or DSO5000. Their web looks weird. http://www.welec.de
People say that the Welec scope is rather bad... http://blog.frankvh.com/2009/06/07/welec-oscilloscope-watch-out/
http://rtr.ca/welec_w2022a/
There is also a datasheet available. http://www.welec.de/data4download/W2000A/W2000Adseu6C8.pdf
Although the scope was introduced in 2007, it has no USB port for an USB flash disc. What the hell?
Here are some photos. http://www.picproje.org/index.php?topic=21309.0 The scope looks ugly inside.
« Last Edit: June 10, 2013, 09:56:16 am by Hydrawerk »
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Offline Hydrawerk

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Re: Welec W2000A - Another weird oscilloscope
« Reply #1 on: June 10, 2013, 09:55:44 am »
It's FFT is said to be crippled. This scope is probably much more worse than Owon scope.
http://rtr.ca/welec_w2022a/
Quote
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).
The scope is said to be produced in EU. The Welec company is from Germany. http://www.welec.de/data4download/W2000A/W2000Adseu6C8.pdf
This looks like an oscilloscope nightmare, folks.
« Last Edit: June 10, 2013, 09:59:26 am by Hydrawerk »
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Offline Hydrawerk

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Re: Welec W2000A - Worst oscilloscope ever??
« Reply #2 on: June 10, 2013, 10:06:33 am »
Note the weird wires on the PCB.  :palm: :palm: :palm:
Oh, this scope must be a bad dream. Wake me up somebody.  :scared: :scared:
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Offline David_AVD

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Re: Welec W2000A - Worst oscilloscope ever??
« Reply #3 on: June 10, 2013, 10:30:35 am »
So I'm guessing you wouldn't buy one then?   ;D
 

Offline Hydrawerk

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Re: Welec W2000A - Worst oscilloscope ever??
« Reply #4 on: June 10, 2013, 10:40:59 am »
NO.  :--
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Offline David_AVD

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Re: Welec W2000A - Worst oscilloscope ever??
« Reply #5 on: June 10, 2013, 10:56:00 am »
I was detecting a faint hint of that.  LOL
 

Online nctnico

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Re: Welec W2000A - Worst oscilloscope ever??
« Reply #6 on: June 10, 2013, 10:58:41 am »
Actually there is a whole group of people working on better firmware. So if you ever wanted to add your own features to your scope, here is your chance.
http://sourceforge.net/projects/welecw2000a/

These scopes used to be sold on Ebay every now and then but I don't know if they can be bought from somewhere nowadays.
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Offline reagle

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Re: Welec W2000A - Worst oscilloscope ever??
« Reply #7 on: June 10, 2013, 12:21:03 pm »
I bought one of these a while back on ebay from Welec store  for a few hundred bucks and promptly returned. The firmware was barely usable.
I know people were making their own versions, but these days there are better choices:)
One thing they were good with was  accepting returns  :-DD

Offline Hydrawerk

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Re: Welec W2000A - Worst oscilloscope ever??
« Reply #8 on: June 10, 2013, 12:42:07 pm »
This is funny: http://www.welec.de/english/06_support/support_specifications_W2014A.htm
What the F*U*C*K??
Quote
KNOW AVAILABLE
1GSa/s Real-Time Sampling, 100MHz
4-Channel Digital Storage Oscilloscope
with VGA (640x480) COLOR Display
Quote
Automatic Measurements
Autoscale
Minor Mathematic Functions, no FFT
No Timebase Delay Function
Quote
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
Quote
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)

Quote
Memory Depth    16k points/channel 50ns/div - 500ns/div
4k points/channel 10µs/div - 200ms/div
:palm: :palm: :wtf:
« Last Edit: June 10, 2013, 12:44:12 pm by Hydrawerk »
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alm

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Re: Welec W2000A - Worst oscilloscope ever??
« Reply #9 on: June 10, 2013, 12:53:41 pm »
Does the company still exist? From what I remember, the company essentially went bankrupt before being able to fix the major problems with this scope, which is why these scopes were selling very cheaply at some point. 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.
 

Offline Hydrawerk

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Re: Welec W2000A - Worst oscilloscope ever??
« Reply #10 on: June 10, 2013, 01:13:26 pm »
Does the company still exist?
I don't know, but their web http://www.welec.de still exists so they apparantly pay for webhosting. But the last note was made in 2008.
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.
Well, not much... We have seen many old obsolete scopes, that are still OK and you don't feel that they are crap.
There are only few scopes that were crap when they were brand new.
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Offline branadic

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Re: Welec W2000A - Worst oscilloscope ever??
« Reply #11 on: June 10, 2013, 08:38:29 pm »
Quote
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.

Thanks for this statement, exactly what I thought while reading the first post.
My guess is that "Hydrawerk", by the way also a german guy, is just a post hunter as he is also active on www.mikrocontroller.net where the main discussion to Welec occures. On the other hand it is always easy to beef others instead of doing something more productive and presenting the results to the community, because it implies the risk of being beefed too ;)
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Offline Hydrawerk

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Re: Welec W2000A - Worst oscilloscope ever??
« Reply #12 on: June 11, 2013, 12:47:51 am »
Well, I don't visit http://www.mikrocontroller.net I am not from Germany, but from Czech Republic (it's near  :) ).
I just found this Welec scope interesting. But I see that it is an old 2007 affair.
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Offline Stonent

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Re: Welec W2000A - Worst oscilloscope ever??
« Reply #13 on: June 13, 2013, 07:11:50 pm »
I'm curious what those 4 QFPs were in the one picture, I couldn't read the writing on them.
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Offline Hypernova

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Re: Welec W2000A - Worst oscilloscope ever??
« Reply #14 on: June 13, 2013, 07:21:23 pm »
I'm curious what those 4 QFPs were in the one picture, I couldn't read the writing on them.

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Offline Hydrawerk

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Re: Welec W2000A - Worst oscilloscope ever??
« Reply #15 on: January 05, 2014, 01:01:41 pm »
Was this Welec / Wittig scope at least comparable to Velleman scopes? They had bandwith up to 30MHz or so. Velleman scopes were quite popular in 2000-2005, when there were no other cheap scopes in Europe. They were really basic, but they did what the specifications said. They were rather OK for the price.
« Last Edit: January 05, 2014, 01:03:13 pm by Hydrawerk »
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Offline GK

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Re: Welec W2000A - Worst oscilloscope ever??
« Reply #16 on: January 05, 2014, 01:46:39 pm »
The worst portable scopes I've come across were those ones by Fluke in the '90s. We still have a couple at work in the cupboard unused that were originally bought for field servicing. They cost a small fortune in their day and were absolutely horrible and completely non-intuitive to use.
« Last Edit: January 05, 2014, 01:48:24 pm by GK »
 

Offline Bored@Work

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Re: Welec W2000A - Worst oscilloscope ever??
« Reply #17 on: January 05, 2014, 09:14:05 pm »
Was this Welec / Wittig scope at least comparable to Velleman scopes? They had bandwith up to 30MHz or so.

Oh come on, you started that topic by looking at the Wittig/Welec bench scope. You even quoted the specs. Didn't you recognizes these were 100 MHz and 200 MHz oscilloscopes, up to four channels, desktop form factor, color VGA LCD display? So really what is this fixation with a seven year old oscilloscope series?

Wittig tried their hands at a desktop oscilloscope. At the same time Rigol and others were coming out with entry-level desktop oscilloscopes in this form factor. Wittig failed and went bankrupt. The market's most severe punishment for producing something not good enough (should happen to more crap oscilloscope manufacturers). So what more punishment you want to see?

The owners founded a new company (Welec) to sell the surplus they somehow managed to rescue from bankruptcy, or to emerge out of bankruptcy to pay off their debts. They sold the oscilloscopes at a much reduced price. So the market fixed that, too - price affecting supply and demand.

At some point they published the original firmware of that desktop oscilloscope. Years ago I saw some part of it. An incredible steaming pile of shit. One of the worst embedded code I have ever seen (if we don't count Android apps as embedded stuff, and if we exclude Arduino). The best example why hardware guys with no real training in software development should never ever write something more difficult than blinking a LED.

A small group of people had years of fun writing their own firmware for that oscilloscope, the only 200 MHz oscilloscope hardware platform you could get to write code for. Compared to the usual pseudo oscilloscope junk hardware like DSO nano.

So really, what is your point? It is dead Jim. It is no more. It is pining for the fjords.
« Last Edit: January 05, 2014, 09:23:22 pm by Bored@Work »
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Offline Hydrawerk

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Re: Welec W2000A - Worst oscilloscope ever??
« Reply #18 on: January 07, 2014, 10:58:29 am »
Anybody remembers this scope Wittig Technologies 22-300? It was sold by Conrad in 2003 or so. But it is weird. According to the user manual, it has no automatic measurements.
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Offline echen1024

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Re: Welec W2000A - Worst oscilloscope ever??
« Reply #19 on: January 07, 2014, 12:21:48 pm »
It is pining for the fjords.
THIS! Is an EX-OSCILLOSCOPE!
I'm not saying we should kill all stupid people. I'm just saying that we should remove all product safety labels and let natural selection do its work.

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Offline DL5TOR

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Re: Welec W2000A - Worst oscilloscope ever??
« Reply #20 on: January 07, 2014, 11:46:51 pm »
But but it's German  :rant:

so it must be a very good product  :palm:

ahh where am i from  :-// :-//

So long

Torsten
 

Offline Bored@Work

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Re: Welec W2000A - Worst oscilloscope ever??
« Reply #21 on: January 08, 2014, 05:12:22 am »
But but it's German  :rant:

so it must be a very good product  :palm:

ahh where am i from  :-// :-//

So long

Torsten

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"Made in England"; "Designed in Germany"
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Offline autoelectra

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Re: Welec W2000A - Worst oscilloscope ever??
« Reply #22 on: November 30, 2015, 10:15:14 am »
Dears,

I bought two of them (2+4 channel versions in 2008 for 250€+350€) , they´re sold in development stage and this was the error of manufacturer, which sold them for little prices and went bankrupt. In earlier years, this was a good price for DSO, many bought them, but customers forget:you get,what you pay fore.
But now, after several years, they are improved with new firmware and better preamplifiers(OPA653 from TI), the 100Mhz versions can be updated to 200Mhz, by D.I.Y.
So, I think, this is not the worst oscilloscope, but the world first oscilloscope with open software and  improvements documented by customers. :-+
I like them, because of production in EU and not from China.
« Last Edit: December 01, 2015, 05:13:09 am by autoelectra »
 


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