Evaluate Used Wittig W2022 Scope - Ideas & Procedures

[Windadct]

Hello PF'ers...

I just picked up a Wittig W2022 Scope on E-bay.

I would like to give it a thorough evaluation, however, this is to be the highest precision item on the bench - does anyone have some good ideas or procedures for running this through its paces?

Perhaps even an eval form?

Thanks!
Paul

 

[davenn]

Hi Windact

have you got or have tried to get a service manual for it ?
if not you could try here ebaman

he has masses of manuals for all sorts of gear
A manual is at least going to give you the specs the scope should be able to achieve
(taking its age/amount of use into account)

a decent quality audio sig-gen/function generator with calibrated level output
would be an essential signal source for testing any scope's performance

cheers
Dave

 

[berkeman]

Hello PF'ers...

I just picked up a Wittig W2022 Scope on E-bay.

I would like to give it a thorough evaluation, however, this is to be the highest precision item on the bench - does anyone have some good ideas or procedures for running this through its paces?

Perhaps even an eval form?

Thanks!
Paul

You should have a DVM that is higher precision, at least for DC measurements and sine wave RMS measurements...

Compare the DC accuracy against your DVM using your DC power supply. Then use an AC square wave source to be sure that you can compensate the 'scope probes to flat signal response.

Does the 'scope have any measurement capabilities of its own, or is it all visual measurements made by you?

 

[meBigGuy]

http://www.welec.de/english/06_support/support_specifications_W2022A.htm

http://www.welec.de/english/06_support/support_04_downloads.htm

I guess the firmware is bad
http://www.eevblog.com/forum/buysellwanted/wittig-technologies-w2022-oscilloscope/

Here is a firmware project
http://sourceforge.net/apps/trac/welecw2000a/

 

[Windadct]

Yes - I'll download the manuals- I and many have some self cal, my DMM is OK - but a few features like bandwith would be tricky.

I was thinking of something like comparing VI curve for a few standard, signal diodes. Their performance should be pretty consistent. Many times when you look at cal you are checking each parameter at once, but IMO many of the digital devices, there are often one or two "tests" that can confirm that pretty much everything is working.

Another woud be Square Wave response - both unfiltered and then filtered. By overlapping results of different test - shortcomings of the test equipment can be ruled out and attributed to the UUT.

Just thinking out loud

Also - thanks for the firmware project - it looks interesting - probably the most common issue/complaint with low end scopes is the software, but in general all software projects are far more difficult then consumers ( and many manufactures) understand. So I want / Need the PC connection - but will see how well the OEMs works and then check the FW Project out.