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#309262 - 19/04/2008 11:22 Re: Welec 2022a third impressions: I'll keep it. [Re: Daniel Wee]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14105
Loc: Canada
Originally Posted By: Daniel Wee
1. Power on zero drift. If you turn on the unit and observe the zero level, you will find that it drifts quite a bit over time - probably due to the lack of thermal compensation.


Are you sure that's not just the AC-coupling doing it's self-centering thing?

Cheers

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#311638 - 28/06/2008 18:36 Re: Welec 2022a second impressions: improving [Re: mlord]
DL3DAZ
new poster

Registered: 17/06/2008
Posts: 1
Originally Posted By: mlord
I loaded the PC software into VMware (under Linux), to see if it was any good.

In case you are interested in downloading sampled data (and maybe later controlling) the scope using Linux, you may want to have a look at some stuff about the W2022A at Google groups.

Regards,
Falk

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#321066 - 05/04/2009 10:54 Re: Welec 2022a second impressions: improving [Re: DL3DAZ]
Shonky
pooh-bah

Registered: 12/01/2002
Posts: 1973
Loc: Brisbane, Australia
I was just having a look at DSOs on ebay and came across the google group for these CROs. This post is interesting:

http://groups.google.com/group/welec-dso/browse_thread/thread/dd72e1ad1d08c430

link to file:
http://welec-dso.googlegroups.com/web/FW...i-BwrUzBGT2hOzg

A year on was it a good purchase Mark? They seem to have disappeared from ebay.
_________________________
Christian
#40104192 120Gb (no longer in my E36 M3, won't fit the E46 M3)

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#321067 - 05/04/2009 11:45 Re: Welec 2022a second impressions: improving [Re: Shonky]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14105
Loc: Canada
They're still on eBay, selling 4-channel versions of the hardware now. It seems that most folks are picking those up for around US$400 or so, which is an okay deal if a real scope is out of the question due to price ($1400 and up) or size (bulky old-style tube scopes).

I like this little beast, and it lives on the workbench and is used from time to time for simple stuff. It's not as buggy as it was originally (firmware got updated slightly last summer), but it's a toy when compared with a "real" / expensive version.

EDIT: For example, it was just fine for debugging the empeg I2C timing last fall (mostly used my logic analyzer there, though) -- no issues at all with that. Ditto for when I was last poking at the temperature sensor circuitry.

I don't regret the purchase at all -- definitely do need a scope here, and anything else (w/200Mhz) was/is simply too much money for here and the little use it does see. So perfect for the weekend hobbyist, but not for a day job. smile

Cheers


Edited by mlord (05/04/2009 12:45)

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#321073 - 05/04/2009 12:04 Re: Welec 2022a second impressions: improving [Re: Shonky]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14105
Loc: Canada
Oooh.. there was even an April Fools Day (joke) posting about these.. very funny, but no warnings for the humour-impaired! smile

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#321091 - 05/04/2009 21:11 Re: Welec 2022a second impressions: improving [Re: mlord]
Shonky
pooh-bah

Registered: 12/01/2002
Posts: 1973
Loc: Brisbane, Australia
I'm a bit confused. Sure it's a joke? Maybe that recent post is, but there are posts about the firmware back in July 2008:

http://groups.google.com/group/welec-dso/browse_thread/thread/56f3c673928f18fb#
_________________________
Christian
#40104192 120Gb (no longer in my E36 M3, won't fit the E46 M3)

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#321095 - 05/04/2009 22:52 Re: Welec 2022a second impressions: improving [Re: Shonky]
tman
carpal tunnel

Registered: 24/12/2001
Posts: 5528
Originally Posted By: Shonky
I'm a bit confused. Sure it's a joke? Maybe that recent post is, but there are posts about the firmware back in July 2008:

http://groups.google.com/group/welec-dso/browse_thread/thread/56f3c673928f18fb#

The firmware was released. That is what the 3rd party stuff is based on. The april fool is that they're sponsoring development and have a big list of desirable features I guess...

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#321097 - 05/04/2009 23:48 Re: Welec 2022a second impressions: improving [Re: tman]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14105
Loc: Canada
Yeah. We've had the source code (incomprehensible) since last summer. There's even a beta release from (unfortunately) April 1 2009 of a rework of it (mostly incomplete at present).

The April Fools is the announcement I linked to, of a development contract to fix the existing firmware and sell updates for $300 to existing owners. Yeah, right. smile

But like I said.. no smilies, so certain nationalities might not get it, and might even think it's a real deal! smile

Cheers

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#321098 - 05/04/2009 23:52 Re: Welec 2022a second impressions: improving [Re: mlord]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14105
Loc: Canada
These days, now that I'm working with OTA television antennas (hobby), I'm really wishing for a 1GHz scope, to cover UHF television frequencies..

And I suppose if I had that already, I'd want a 3GHz scope for WiFi and satellite. But then I'd want a 6GHz scope for 802.11A. And so on.. smile

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#321105 - 06/04/2009 00:56 Re: Welec 2022a second impressions: improving [Re: mlord]
Shonky
pooh-bah

Registered: 12/01/2002
Posts: 1973
Loc: Brisbane, Australia
smile Understand the need for bigger, better, more. Whilst I'm looking at a machine for a day job, it's also for home and coming out of my pocket (though it would be a tax dedcution).

I did have a quick look at the firmware. What a shocker. Basically all in one file...
_________________________
Christian
#40104192 120Gb (no longer in my E36 M3, won't fit the E46 M3)

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#321106 - 06/04/2009 01:35 Re: Welec 2022a second impressions: improving [Re: Shonky]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14105
Loc: Canada
Originally Posted By: Shonky
Whilst I'm looking at a machine for a day job, it's also for home and coming out of my pocket (though it would be a tax dedcution).

Okay, how's this for clarity: smile

At US$400, *delivered*, I think a 4-channel 200Mhz scope like this is a pretty good deal, and way cheaper than any alternatives. It's slow, has the odd bug here and there, but it really does work.

And it has a colour display, decent menuing system, and takes up practically no space at all on the workbench. If I didn't already have one, I'd jump at the current offers! wink


Attachments
scope.jpg

Description: My scope, in a custom shelving unit made to fit around it.



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#321107 - 06/04/2009 01:42 Re: Welec 2022a second impressions: improving [Re: mlord]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14105
Loc: Canada
And the auto white-balance on the 40D seems to work rather well. smile
With my previous camera (20D), that photo would have had a blue-green tint!

Cheers

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#321295 - 09/04/2009 16:04 Re: Welec 2022a second impressions: improving [Re: mlord]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14105
Loc: Canada
Oh, forgot to mention. I did use the scope again quite recently, to actually *measure* the velocity factor for some RG-59 coaxial cable.

I'm making coax-loop baluns for some TV antennas, and it's very important to know how fast signals pass through the coax.

The nice thing about a scope this quick (1gs/sec) is that it only takes a few metres of coax to have sufficient delay that it can be measured on the scope!

The coax I had on hand here measured as a VF of 0.80c, which is quite close to the oft posted ballpark figures for RG-59 on the web (which range around 0.78 to 0.82 or so), for foam-core stuff.

Cheers

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#321296 - 09/04/2009 17:07 Re: Welec 2022a second impressions: improving [Re: mlord]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31298
Loc: Seattle, WA
Originally Posted By: mlord
The nice thing about a scope this quick (1gs/sec) is that it only takes a few metres of coax to have sufficient delay that it can be measured on the scope!


This reminds me of something I've been meaning to ask the board's opinion about. I'll put it in another post shortly.
_________________________
Tony Fabris

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#324635 - 26/07/2009 15:52 Re: Welec W2022A Review page [Re: mlord]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14105
Loc: Canada
Originally Posted By: mlord
Wow.. there are just so many firmware bugs, that I've now created a web page just to help track them. And since there is no other third-party info available on these products, it may as well be a review page.

My Welec W2022A Review is now up.


A lot has happened with these scopes of late. Last summer, the (horrible) source code for the firmware was released, and over this past winter/spring some German chaps have been fussing away at it.

The current "beta" release of fixes/enhancements, based on the original factory firmware, is actually rather good. I've installed it on my own scope here, and most of the old bugs vanished, while some new features (re)appeared.

The FFT functionality has returned with a vengence, though it's still not useful beyond really low frequencies, and the scope is definitely a lot better behaved now.

The best thing with the new firmware though, is they've figured out how to reduce the inherent noise in the measurements, to perhaps half of what it used to be. This is good.

Related to that last point -- another person has been poking at the FPGA code, and determined that *all* of the visible noise is just the result of some firmware bugs. He's recoded some of the VHDL and posted youtube videos (search for welec) showing the difference. Quite astounding results, though it could be a long time before changes like that make it back in the new firmware releases.


Attachments
a.jpg

Description: from one of the youtube videos..



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#359880 - 04/10/2013 18:17 Re: Welec W2022A Review page [Re: mlord]
sn00p
addict

Registered: 24/07/2002
Posts: 608
Loc: South London
Digging up an old thread.

We just bought a Rigol DS2000 series scope and it's brilliant. Because we're now doing a lot more analog stuff I find myself needing a lot more features out of the scope than I needed before and our old tektronix scope is just becoming more and more infurating to use!

We also bought a series 4000 function generator at the same time. We've needed a function generator for a while, I kept getting asked questions about our signal processing that I couldn't really answer without injecting known sets of signals into the front end, so hopefully I'll be able to give some definitive answers now.

Got to say that so far we're very impressed with the Rigol stuff.

Adrian

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#359881 - 05/10/2013 12:47 Re: Welec W2022A Review page [Re: sn00p]
K447
old hand

Registered: 29/05/2002
Posts: 701
Loc: Toronto, Ontario, Canada
Has the state of the art in regards to osciliscope fronts ends for an iPad improved?

Is Oscium still the only player?

I don't need really high input bandwidth but I do need a large and high pixel display, hence the interest in using my own 'computer' for the user interface and display. And more than two analog input channels.

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#359892 - 07/10/2013 14:13 Re: Welec W2022A Review page [Re: K447]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31298
Loc: Seattle, WA
Originally Posted By: K447
Has the state of the art in regards to oscilloscope fronts ends for an iPad improved?


"Front ends"? From the looks of the photos on the Oscium main page, it looks like the iPad actually *is* the 'scope in some cases. The dongle has the test probes on it. That's kind of impressive. I didn't know anyone was doing that. Wow.
_________________________
Tony Fabris

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#359894 - 08/10/2013 06:20 Re: Welec W2022A Review page [Re: tfabris]
sn00p
addict

Registered: 24/07/2002
Posts: 608
Loc: South London
That's what I thought.

The scope (actually all the rigol equipment we bought) has usb and can be controlled with SCPI commands. This is particularly useful because 4 days out of 5 I'm hundreds of miles away from the physical scope and connected device. It's great to be able to remotely control it.

Same goes for the power supply, I can turn on/off channels set voltage & current limit etc.

And the multimeter, again I can set it into the mode I want and read back the readings etc.

So handy!

I had a good play with the scope yesterday and it's amazing for the price, not only does it feel physically solid (and expensive), the software doesn't seem flakey and it seems well thought out and comprehensive.

If only I could convince the wife that we needed one!

Adrian

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#359956 - 12/10/2013 02:33 Re: Welec W2022A Review page [Re: K447]
altman
carpal tunnel

Registered: 19/05/1999
Posts: 3454
Loc: Palo Alto, CA
Originally Posted By: K447
Has the state of the art in regards to osciliscope fronts ends for an iPad improved?

Is Oscium still the only player?

I don't need really high input bandwidth but I do need a large and high pixel display, hence the interest in using my own 'computer' for the user interface and display. And more than two analog input channels.


When I looked at the Oscium it turned out it had no capture depth, ie it captured exactly one screenful, with no zooming possible. Not sure if that was just early software, but my dreams of pinch-zooming on a deep buffer died frown

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#359958 - 12/10/2013 02:59 Re: Welec W2022A Review page [Re: altman]
K447
old hand

Registered: 29/05/2002
Posts: 701
Loc: Toronto, Ontario, Canada
Originally Posted By: altman
Originally Posted By: K447
Has the state of the art in regards to osciliscope fronts ends for an iPad improved?

Is Oscium still the only player?

I don't need really high input bandwidth but I do need a large and high pixel display, hence the interest in using my own 'computer' for the user interface and display. And more than two analog input channels.


When I looked at the Oscium it turned out it had no capture depth, ie it captured exactly one screenful, with no zooming possible. Not sure if that was just early software, but my dreams of pinch-zooming on a deep buffer died frown
Seems to still be the case frown

USB connected 'scopes' seem to be all over the low-end map, hard to figure out what is actually decent.

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