Anyone using a Welec W20xxA DSO?

Started by Falk Willberg July 8, 2009
Jon Kirwan schrieb:
> On Thu, 09 Jul 2009 08:59:58 -0700, Joerg <invalid@invalid.invalid> > wrote: > >>> Also very important: It has a lot of "Spielwert", (if someone could >>> translate that, please ;-) ) ... >> Fun factor. So you are probably not married :-) > > The actual word(s) break out as Spiel (play) and wert (value or worth) > and it made me think of something more gaming-like, such as "replay > value" than "fun factor." But fun factor is much better. Would > Spielwert also be used for the meaning of "replay value" in video > games, for example? Or is there another term for that?
that would be "Wiederspielwert". Replay translated literally would be Wiederspiel. But nobody says "Wiederspiel". Falk
Nico Coesel schrieb:
> Falk Willberg <Faweglassenlk@falk-willberg.de> wrote: > >> Jan Panteltje schrieb: >> >> ... >> >>> For about 520 Euro you can buy a Rigol with 1G samples, >> As I am using Linux, I am quite happy with the open source. So I was >> able to add functions *I* wanted to have. >> >> Also very important: It has a lot of "Spielwert", (if someone could >> translate that, please ;-) ) and I don't want to use a 30 MHz analog >> LG5020 (or so) for 300&curren; any longer... > > This is quite interesting. An oscilloscope for which you can hack your > own firmware... Except for using 4 ADCs per channel the concept of the > design isn't bad.
The "Russian Group" is using them as a cheap training platform for FPGA programming ;-) They are trying different approaches to make a good DSO on this platform. But as they have a much longer way to go... Falk -- Weglassen in my email address must be left out
On a sunny day (Thu, 09 Jul 2009 22:30:26 GMT) it happened nico@puntnl.niks
(Nico Coesel) wrote in <4a566f2f.3300623593@news.planet.nl>:

>Falk Willberg <Faweglassenlk@falk-willberg.de> wrote: > >>Jan Panteltje schrieb: >> >>... >> >>> For about 520 Euro you can buy a Rigol with 1G samples, >> >>As I am using Linux, I am quite happy with the open source. So I was >>able to add functions *I* wanted to have. >> >>Also very important: It has a lot of "Spielwert", (if someone could >>translate that, please ;-) ) and I don't want to use a 30 MHz analog >>LG5020 (or so) for 300&#2013266084; any longer... > >This is quite interesting. An oscilloscope for which you can hack your >own firmware... Except for using 4 ADCs per channel the concept of the >design isn't bad.
I think it is VERY bad. Look at the diagram of the channel amplifiers. All opamps. You may as well replace that by triangles with NOISE written in it. And that is most likely why the thing has 4 bits noise of the 8 bits ADC. I know this will piss of those who worked hard to improve that firmware ;-) But get real, long long time ago, tens of years, somebody at Tek published (long before there was anything like Internet or 'online') the diagram of a *300MHz* analog Y amp for a CRT scope in a Dutch electronics magazine. It used discretes, BFY90, and could output tens of volts to the CRT. And of course it was not noisy. I build it, and used an East German CRT with similar bandwidth, that was my third scope... Many many years later I met the person who published that at Tek, he told me Tek was not too happy with him publishing that diagram, but in my view it sure made a good commercial for their scopes :-) So, anyways, with a couple of discretes you can make a much better amp in my opinion, probably cheaper too Why the guy used op-amps is perhaps the same reason the software guy used C++? No clue, and opamps are so easy???? Well now you can flame if you want. Although I am not sure that design will burn. LOL hehe
On Fri, 10 Jul 2009 09:16:27 +0200, Falk Willberg
<Faweglassenlk@falk-willberg.de> wrote:

>Jon Kirwan schrieb: >> On Thu, 09 Jul 2009 08:59:58 -0700, Joerg <invalid@invalid.invalid> >> wrote: >> >>>> Also very important: It has a lot of "Spielwert", (if someone could >>>> translate that, please ;-) ) ... >>> Fun factor. So you are probably not married :-) >> >> The actual word(s) break out as Spiel (play) and wert (value or worth) >> and it made me think of something more gaming-like, such as "replay >> value" than "fun factor." But fun factor is much better. Would >> Spielwert also be used for the meaning of "replay value" in video >> games, for example? Or is there another term for that? > >that would be "Wiederspielwert". Replay translated literally would be >Wiederspiel. But nobody says "Wiederspiel".
I figured a literal translation wouldn't cut it, already. So what work is used, then, for the case describing a game that retains its Spielwert very well even after playing it a few times? Or is it just that it is explained with more than one word? Thanks, Jon
On Fri, 10 Jul 2009 17:16:17 GMT, Jon Kirwan
<jonk@infinitefactors.org> wrote:

>So what work
Sorry, I meant 'so what _word_..." Jon
"Jan Panteltje" <pNaonStpealmtje@yahoo.com> wrote in message 
news:h3750b$lfl$1@news.albasani.net...
> Look at the diagram of the channel amplifiers. > All opamps. > You may as well replace that by triangles with NOISE written in it. > And that is most likely why the thing has 4 bits noise of the 8 bits ADC.
What's the ADC's input range? If it's something like 1V, that's 3.9mV/bit. which in a bandwidth of 100MHz 390nV/sqrt(Hz) -- a VERY noisy amplifier. In other words... I do think one *could* readily design a 100MHz front-end with an op-amp these days and still achieve 8 bit resolution. Whether or not they did is another question, of course...
> So, anyways, with a couple of discretes you can make a much better amp > in my opinion, probably cheaper too
Probably so, but they probably figured it was already cheap enough and didn't have the skills to implement a discrete design.
> Why the guy used op-amps is perhaps the same reason the software guy used > C++? No clue, > and opamps are so easy????
Pretty much anything you get from Tek or Agilent these days is going to have plenty of C or C++ (or even .Net!) in it these days. ---Joel
Jon Kirwan wrote:
> On Thu, 09 Jul 2009 16:15:25 -0700, Joerg <invalid@invalid.invalid> > wrote: > >> Jon Kirwan wrote: >>> On Thu, 09 Jul 2009 08:59:58 -0700, Joerg <invalid@invalid.invalid> >>> wrote: >>> >>>>> Also very important: It has a lot of "Spielwert", (if someone could >>>>> translate that, please ;-) ) ... >>>> Fun factor. So you are probably not married :-) >>> The actual word(s) break out as Spiel (play) and wert (value or worth) >>> and it made me think of something more gaming-like, such as "replay >>> value" than "fun factor." But fun factor is much better. Would >>> Spielwert also be used for the meaning of "replay value" in video >>> games, for example? Or is there another term for that? >>> >> I've been away from Germany for too long but I believe "Spielwert" >> always had a meaning close to what "Fahrvergnuegen" is in our Volkswagen >> ads over here. I've never seen that word on a video game or arcade >> machine. "Spiel" on those machines means game, as in how many games you >> have left after inserting x amount of cash into the machine. >> "Freispiele" on a slot machine or pinball machine is the number of games >> (or pulls) you didn't pay for but won during a run. >> >> Mostly "Spielwert" is (or at least was) used if something had the >> potential of being entertaining but not necessarily of being all that >> useful. Like that midlife-crisis sports car purchase :-) > > Ah. Do NordDeutsch carry a stronger negative judgment about Spielwert > als s&#2013266172;dDeutsch? >
No idea. I'll leave that to Falk since he lives there ;-) -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
Joel Koltner wrote:
> "Jan Panteltje" <pNaonStpealmtje@yahoo.com> wrote in message > news:h3750b$lfl$1@news.albasani.net... >> Look at the diagram of the channel amplifiers. >> All opamps. >> You may as well replace that by triangles with NOISE written in it. >> And that is most likely why the thing has 4 bits noise of the 8 bits ADC. > > What's the ADC's input range? If it's something like 1V, that's 3.9mV/bit. > which in a bandwidth of 100MHz 390nV/sqrt(Hz) -- a VERY noisy amplifier. > > In other words... I do think one *could* readily design a 100MHz front-end > with an op-amp these days and still achieve 8 bit resolution. Whether or not > they did is another question, of course... >
Sure, you've got the whole THS-series from Texas to do it with. Can be had for around five bucks a pop and great noise performance. I did it even in the 80's. Ok, the Harris amps back then were power-hungry and expensive but then, thanks to VCRs becoming ubiquitous, there was (and still is) this gem for under a buck: http://focus.ti.com/lit/ds/symlink/ua733.pdf
>> So, anyways, with a couple of discretes you can make a much better amp >> in my opinion, probably cheaper too > > Probably so, but they probably figured it was already cheap enough and didn't > have the skills to implement a discrete design. >
Very common these days :-(
>> Why the guy used op-amps is perhaps the same reason the software guy used >> C++? No clue, >> and opamps are so easy???? > > Pretty much anything you get from Tek or Agilent these days is going to have > plenty of C or C++ (or even .Net!) in it these days. >
My horror was a scope with a Windows-OS on there. Could have been LeCroy, don't remember, because I instantly told the client we'd need a "real" scope. This often leads to a trip into their basements where there is a pile of Tektronix mainframes and stuff that nobody has used in years. Usually they still work just fine. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
"Joerg" <invalid@invalid.invalid> wrote in message 
news:7bpf5qF24qe16U1@mid.individual.net...
> Sure, you've got the whole THS-series from Texas to do it with.
Yep, a THS4031 makes a pretty decent RF amplifier if you can tolerate the ~10dB noise figure.
> This often leads to a trip into their basements where there is a pile of > Tektronix mainframes and stuff that nobody has used in years. Usually they > still work just fine.
It might be a good interview technique to take a potential employee past a bunch of that stuff and see whether or not his eyes light up appropriately when show them a 2465b. :-)
Joel Koltner wrote:
> "Joerg" <invalid@invalid.invalid> wrote in message > news:7bpf5qF24qe16U1@mid.individual.net... >> Sure, you've got the whole THS-series from Texas to do it with. > > Yep, a THS4031 makes a pretty decent RF amplifier if you can tolerate the > ~10dB noise figure. >
I like the THS4021 better, it's faster. The noise should be ok for a scope. For really low noise measurements I use a couple of HP lab amplifiers up front anyhow.
>> This often leads to a trip into their basements where there is a pile of >> Tektronix mainframes and stuff that nobody has used in years. Usually they >> still work just fine. > > It might be a good interview technique to take a potential employee past a > bunch of that stuff and see whether or not his eyes light up appropriately > when show them a 2465b. :-) >
Oh yeah! One of the best every-day scopes ever built. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.