Test Equipment Anonymous (TEA) group therapy thread

[mnementh]

Siglent have no reliable UK reseller so I'd buy a better Rigol over a Siglent if I wanted to spend more money.

I don't buy that scopes really go obsolete. Better ones come out but that doesn't mean the old ones are less useful than before. The interface between them and the universe is quite stable

Yep, that interface would be the users and we have been stable for centuries 

From mobile device so predictive text might have struck again [emoji83]

Obsolete from a retail/buying standpoint, which is precisely the context of that particular discussion. If you're buying a new gadget and paying new price, you're going to buy the new shiny with all the features as opposed to last decade's model unless prices are drastically different.

Your argument applies to an entirely DIFFERENT context; more the baseline context of TEA itself. Which is borne out in the fact we're both still quite happy with our 1054Zs. 

As for the "stable interface" comment... I wouldn't touch that with a bargepole. 


mnem
"Stable-ish" indeed...

[med6753]

Another delivery courtesy of Mnem. This has the knob and fuse cap for the 2465. Plus some cool stuff. That large item is a portable airbrush meant for applying a sunless tanning lotion. That could come in handy for other applications I just don't know what yet.  I don't know what the item in the lower left is.  It has a note attached that I have to read. And then some assorted parts. Thanks for the stuff....you're a cool dude.     

[mnementh]

Glad it FINALLY got to you... between my car problems and the Post deciding we didn't need service Saturday before a holiday, I thought it was NEVER gonna happen. 

The sprayer was one of those weird 99c store finds; I bought a shedload of them for the Co2 cartridges, then I found the sprayer was actually a useful little tool. I've used them to spray a model car body, apply wood stain, apply paint after fixing a hole in the wall, and a few other things I can't remember right now. 

Top left are some car speaker tweet/mids I kept due to their curious construction; both elements are peizo. Directly under that is a Li-ion charge/output controller from some laptop external battery packs I used to use for extended onsite service calls; they come in a shell with a large 3S2P (or was it 4S2P?) 18650 battery pack. Think same idea as a USB PowerBank, only ~19V in/19V out.

The wedge-shaped PCB is a 900MHz (I think) audio RF module I got from some place like American Science & Surplus.

The little grey plastic widget is a multifilar helix GPS antenna I've saved in the bottom of my junk drawer since Magellans were the size of a 3.5" hard drive. VERY interesting construction.

And the widget you're wondering about is an original iBlue BT GPS unit; I used to use it for waypoint flight-control of multicopters with Mission Planner on my old ToughBook before I bought one with GPS built-in. Quite ingenious device; it is an entirely self-contained (if you can find a battery for it) siRF3 chipset GPS unit that sends NMEA-standard data out over BT SPP slave connection. The notes tell you what size battery to shop for, and where to Google for the documentation online.

I'm glad I could help restore your 2465, and I hope you have fun with the "random" I tossed in to fill up the box.


mnem
This must be Friday; I never could quite get the hang of Fridays...

[Berni]

As I said before.....DSO's are a new animal to me. I did some more playing around and I got the glitch.

This is why a high resolution display and intensity gradation makes a world of difference in having a digital scope show the same sort of fidelity as a analog scope.

EDIT: I just wanted to make a demo of it...aaand my Tektronix signal generator is not turning on. Push the power button and nothing happens. Dang it my repair cue just got even longer!

[tautech]

As I said before.....DSO's are a new animal to me. I did some more playing around and I got the glitch.

Good scope work med.

The DL's are a model I never bought in as I thought they had substandard specs and TBH all the similar CNL, CML and CFL now fall into the same basket compared to the later X and X-E models of which some have the same sampling rate as C** models but otherwise have a truckload more memory, better sensitivity, ERES, dot mode and so on.

Anyways just goes to show how a lowly DSO can nearly foot it in some situations against the mighty Tek 2465, the flagship of it's era. 

[mnementh]

OMG... laying the drama on a little thick, doncha think? 

The original point still obtains... the 2465 showed the glitch as easily as focusing a microscope. He had to have an idea what the problem was to set up the DSO to show it.

The analog scope STILL holds value for just this reason; you don't have to outwit it to get useful results.


mnem
*witling*

[Specmaster]

OMG... laying the drama on a little thick, doncha think? 

The original point still obtains... the 2465 showed the glitch as easily as focusing a microscope. He had to have an idea what the problem was to set up the DSO to show it.

The analog scope STILL holds value for just this reason; you don't have to outwit it to get useful results.


mnem
*witling*

I tend to agree with you here, but it has to be said that in the first screen shots, we weren't comparing apples with apples as the 2465 set at 20mV / div and the DSO set to 50mV div. I also tend to think (as a none user/owner of a DSO other that a lowly DSO138) that the screen is a bit off putting as the traditional CRO is a 8 x 10 grid and the DSO is a 8 x 15 grid and I suspect thats could be a trap for a new player as I suspect that they would try to replicate the imagery shown on a CRO on DSO which is never going to look the same as the display is going to look stretched width-ways. Also the image on the 2465 is considerably cleaner looking than the DSO and TBH I would have expected the DSO to have been the cleaner image seeing as it set to a higher v/div, lifting it further away from any background noise factor

[tautech]

OMG... laying the drama on a little thick, doncha think? 

The original point still obtains... the 2465 showed the glitch as easily as focusing a microscope. He had to have an idea what the problem was to set up the DSO to show it.

The analog scope STILL holds value for just this reason; you don't have to outwit it to get useful results.


mnem
*witling*

Small difference; lowly DSO vs TOL professional CRO, fair comparison do you think ? 

Little example of irregular glitch spotted, confirmed and searched for and triggered on.
https://www.eevblog.com/forum/testgear/siglent-sds1204x-e-released-for-domestic-markets-in-china/msg1370717/#msg1370717

Try that with your CRO.   

[bd139]

Yes. If you evaluate on price point, spend $10k on a scope now and compare to a 2465

[Specmaster]

Seeing as the Tek 2465 seems to hail from 1989 and the Siglent I think from 2014?, there has been 25 years of development since the 2465 so its perfectly logical to have expected that the lowly Siglent was or ought to have been almost upto or equivalent to the specs of 2465 as performances and specs have risen in general at an alarming rate in that time. I'd have thought that was considered to be top level in 1989 ought to have been the entry level today given that time of evolution. In most other sciences that seems to be the case, Hi-Fi, TV, Radio, Cars and cameras etc.

In that light, the "lowly" Siglent is only lowly when compared to what is on offer today  and that must be way beyond what the 2465 offered back in the day??

[med6753]

OMG... laying the drama on a little thick, doncha think? 

The original point still obtains... the 2465 showed the glitch as easily as focusing a microscope. He had to have an idea what the problem was to set up the DSO to show it.

The analog scope STILL holds value for just this reason; you don't have to outwit it to get useful results.


mnem.
*witling*

In defense of the Siglent. I think the problem was more operator inexperience rather than a functional issue. Ever since I bought it it's been the "red headed step child" on my bench and mostly sat unused. I haven't even opened it up and looked inside!  But now I'm going to force my CRO's to make peace with it. We can all co-exist.

Tautech, can this puppy be hacked to 100MHz? Just kidding...I don't want to mess with the firmware and risk bricking it.

[mnementh]

OMG... laying the drama on a little thick, doncha think? 

The original point still obtains... the 2465 showed the glitch as easily as focusing a microscope. He had to have an idea what the problem was to set up the DSO to show it.

The analog scope STILL holds value for just this reason; you don't have to outwit it to get useful results.


mnem
*witling*

Small difference; lowly DSO vs TOL professional CRO, fair comparison do you think ? 

Little example of irregular glitch spotted, confirmed and searched for and triggered on.
https://www.eevblog.com/forum/testgear/siglent-sds1204x-e-released-for-domestic-markets-in-china/msg1370717/#msg1370717

Try that with your CRO.   

Aaaand now we've just gone recursive... 

...right back to my original statement that the the "one or the other" argument is just plain stupid. Each excels at different things, and decent CROs are cheap and plentiful enough that there's simply no good reason NOT to have both on your bench.


Here's another way to look at it: Right now is probably a watershed moment in this regard; this still-useful test equipment is artificially very cheap due to the fact that cheap DSOs have driven the technology to a small laboratory market where it can still sell for a price reasonable to the cost of keeping it up.

This is the time to take advantage of that fact; as in 20 years, due to the cheapness of production of all-solid-state devices dictated by Moore's Law, they will have become a niche product that costs exponentially more to own because the CRTs require precision manufacturing whose art, process and technology has been lost just like that of Nixie tubes.

Salvageable examples will be as sought-after as 1st gen Mac tube amplifiers and Stromberg-Carlson Console Televisions, and ANY decent CRO will be sought-after in the same way as we in this forum revere laboratory-condition 2465s now.


mnem
It's like beating your knee with a monkey wrench 'cuz it feels so good when you stop...

[mnementh]

Seeing as the Tek 2465 seems to hail from 1989 and the Siglent I think from 2014?, there has been 25 years of development since the 2465 so its perfectly logical to have expected that the lowly Siglent was or ought to have been almost upto or equivalent to the specs of 2465 as performances and specs have risen in general at an alarming rate in that time. I'd have thought that was considered to be top level in 1989 ought to have been the entry level today given that time of evolution. In most other sciences that seems to be the case, Hi-Fi, TV, Radio, Cars and cameras etc.

In that light, the "lowly" Siglent is only lowly when compared to what is on offer today  and that must be way beyond what the 2465 offered back in the day??

Okay... now push it towards 1GHz and see which one stops giving anything useful first... that's the difference between "laboratory-grade" and "Entry-level".

And that is why a properly working 2465 STILL presents an excellent value, even in this day & age. Maybe ESPECIALLY so.


The Siglent doesn't NEED to be defended; it ISN'T BEING ATTACKED. Its low manufacturing cost has made it the defacto winner here, as it and its brothers have pretty much killed off the manufacture of the core technology of CROs. That doesn't mean it's necessarily BETTER; only that it's cheaper to make, so offers a higher cost-profit ratio.


mnem
 

[tautech]

Tautech, can this puppy be hacked to 100MHz? Just kidding...I don't want to mess with the firmware and risk bricking it.

I don't think so as they're only available as 50 MHz models.
https://www.siglentamerica.com/digital-oscilloscopes/sds1000dl-series-digital-storage-oscilloscopes/

Let alone you've only 500MSa/s and 30Kpts memory which will make it pretty ordinary near 100 MHz for anything other than repetitive waveforms.

[tautech]

OMG... laying the drama on a little thick, doncha think? 

The original point still obtains... the 2465 showed the glitch as easily as focusing a microscope. He had to have an idea what the problem was to set up the DSO to show it.

The analog scope STILL holds value for just this reason; you don't have to outwit it to get useful results.


mnem
*witling*

Small difference; lowly DSO vs TOL professional CRO, fair comparison do you think ? 

Little example of irregular glitch spotted, confirmed and searched for and triggered on.
https://www.eevblog.com/forum/testgear/siglent-sds1204x-e-released-for-domestic-markets-in-china/msg1370717/#msg1370717

Try that with your CRO.   

Aaaand now we've just gone recursive... 

...right back to my original statement that the "the "one or the other" argument is just plain stupid. Each excels at different things, and decent CROs are cheap and plentiful enough that there's simply no good reason NOT to have both on your bench.

It's not stupid !
You conveniently overlook the fact many don't have the skill, tools or understanding to maintain or repair a CRO and yes a 2465 or any from the same family are excellent scopes but the complexity that is encountered in attempting repair of one is way past what many would choose to undertake. Some might say that their current market value is no more than $1/MHz for good reason.
When looking at the bigger picture for those wanting their first scope none of the above can or should be discounted.

[tggzzz]

TBH I would have expected the DSO to have been the cleaner image seeing as it set to a higher v/div, lifting it further away from any background noise factor

Er, no, except at the most sensitive range.

DAC is fixed number of bits, and screen height is a fixed number of pixels. In low-end scopes you get one (DAC) bit resolution per pixel whatever the volts/div or volts/pixel.

[tggzzz]

Small difference; lowly DSO vs TOL professional CRO, fair comparison do you think ? 

That's only one comparison, and not a very enlightening one.

Another, arguably more useful, is to compare what you can get for a fixed price - in this case a couple of hundred pounds or so.

[med6753]

I think we can all agree that any well equipped bench should have at least one example of a CRO and DSO. But if you're gonna run solo I hate to say it but it should be a modern feature packed DSO. Especially if you're heavy into digital. Me being the old fart that I am will always favor a CRO because I grew up with them, know how to use them, and don't mind fixing them when they go boom. And they WILL go boom and stink up the bench with magic smoke. I just consider that the joy of ownership and keeping the old iron alive.

Speaking of which....tomorrow I have no plans other than to finally get the vertical board out of the Tek 465 and figure out why channel 2 is FUBAR. If you're all good boys I may post some pron. And if you're super good maybe I'll take the Siglent apart for the first time as a bonus. You know what Dave sez...."don't turn it on, take it apart!"         

[tautech]

Small difference; lowly DSO vs TOL professional CRO, fair comparison do you think ? 

That's only one comparison, and not a very enlightening one.

Another, arguably more useful, is to compare what you can get for a fixed price - in this case a couple of hundred pounds or so.

The last 4 CRO's I've acquired I got for nicks and my time like anyone else's need be factored into the real cost of getting a CRO and fixing it or keeping it going. I've bought many broken ones in years gone by and patched them up, given a good clean and added new probes and sold them on. Much like bd139 does and that's how I got into this initially. For some time I've wanted a 2465 or similar but even with the good, maybe better than basic skills I've gained the unobtainium IC and the battery supported EEPROM is shit no one needs excepting the most dedicated of Tek fans.
Even if we look at cheaper CRO options you have to go someway back to find stuff that is purely analog and straightforward enough for the novice to repair. Having linear PSU's would be a good guiding choice along with jellybean componentry and the manuals of quality like the Tek and HP of old. So there's always the cost of a re-cap to consider plus the cost of the time to do it hovering over a buyers head too.
It all adds up to not so cheap anymore.

[Mr. Scram]

The only problem there is that these scopes aren't exactly in the same price category anymore. I bought my 1054Z for $329 shipped from TEq on sale (actually, they price-matched a loss-leader sale Arrow was having, then hooked me up with a 50-ohm feed-thru terminator to sweeten the deal); street price is $350-379. The SDS1104X-E street price is $479-499 shipped, and the SDS1204X-E is $749-799.

It looks like you do get more for your money with the 1104X, but it's on average $150 more, and the 1204X is twice the price. Just to put things in perspective.

That said... buying a 'scope is like buying gaming computer gear or buying a big-screen TV; in order not to be obsolete by the time you get it home, you should dig deep in your wallet... so deep it makes your gonads ache... and buy as high on the food chain (while still shopping carefully with an eye towards bang:buck ratio) as you can with every penny you can scrape up, beg or borrow. 6 months down the road when you see the newest models coming out you won't regret the extra money spent, and you'll be wishing you had if you don't.


Cheers,


mnem
Money hurts.

You're hitting the nail on the head with the first bit. The Siglent proponents typically neglect to mention that while the new Siglent scopes are slightly more capable, they're also significantly more expensive. If that's the bit you need it's a good buy, but for a lot of people it's a marginal improvement for a lot of extra money. The DS1054Z and the Siglents aren't really competing each other, the price difference is too big.

[mnementh]

Aaaand now we've just gone recursive... 

...right back to my original statement that the "the "one or the other" argument is just plain stupid. Each excels at different things, and decent CROs are cheap and plentiful enough that there's simply no good reason NOT to have both on your bench.

It's not stupid !
You conveniently overlook the fact many don't have the skill, tools or understanding to maintain or repair a CRO and yes a 2465 or any from the same family are excellent scopes but the complexity that is encountered in attempting repair of one is way past what many would choose to undertake. Some might say that their current market value is no more than $1/MHz for good reason.
When looking at the bigger picture for those wanting their first scope none of the above can or should be discounted.

Dude... you need a Tin Woodsman, a Cowardly Lion and an impertinent Teenage Girl in red slippers to go with that Straw Man you've got there. 

For THOSE folks, do you REALLY think a DSO, with basic features often buried under multiple levels of menus and all of the complexities of digital sampling theory to learn in order to use properly, is a better choice when you're already trying to learn "This is an Amp, this is a Volt, together with Resistance, Inductance and Capacitance they make everything electronic go" fundamentals? Especially in a time when you can pick up a working CRO for $50-150 (often with warranty) on fleaBay ANY DAY of the week?

Arguing that you HAVE TO CHOOSE ONE OR THE OTHER is stupid; therefore any argument predicated upon that notion is similarly stupid.


mnem
    

[tautech]

I also tend to think (as a none user/owner of a DSO other that a lowly DSO138) that the screen is a bit off putting as the traditional CRO is a 8 x 10 grid and the DSO is a 8 x 15 grid and I suspect thats could be a trap for a new player as I suspect that they would try to replicate the imagery shown on a CRO on DSO which is never going to look the same as the display is going to look stretched width-ways. Also the image on the 2465 is considerably cleaner looking than the DSO and TBH I would have expected the DSO to have been the cleaner image seeing as it set to a higher v/div, lifting it further away from any background noise factor

Some deeper understanding of the basic differences and operation principles between a CRO and DSO are needed.
Analog CRO's are just that, analog, in the way that there's a defined signal path all the way to the CRT but let's just look at the vertical axis for simplicity.
What produces the clean crisp trace is the quality of the CRT and associated circuitry, after all it's just only a stream of electrons that needs to be only wide enough to provide good resolution/visibility.

DSO's on the other hand as tggzzz briefly comments on, gather data sample points and then plots them on the display by way of reconstruction and then interpolation to display the waveform we recognize.
Unlike a CRO where the display is near realtime, the DSO display cannot be updated at such high rates as a CRO sweep so the imagery is uploaded as a 'batch' if you like to the display at much slower rates.
So within each batch even for a repetitive waveform there are variations in the data points  that manifest themselves in an apparently fussy displayed trace. Lower display vertical pixel counts can suppress this to some degree but we want higher vertical resolution not lower.
So how do we clean up the traces to something like a CRO ?
There's a couple of common solutions, HiRes/ERES or Averaging.
They achieve similar results but HiRes preserves waveform detail better.
Simply if we think of the 3 lines of data below then extract the upper and lower for a more defined trace.

---------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------

Dave's done a couple of vids to help DSO owners get their heads around how to deal with their apparently noisy scopes:
https://www.eevblog.com/2014/04/10/eevblog-601-why-digital-oscilloscopes-appear-noisy/
https://www.eevblog.com/2014/04/27/eevblog-610-why-digital-scopes-appear-noisy-part-2/

[Mr. Scram]

Dude... you need a Tin Woodsman, a Cowardly Lion and an impertinent Teenage Girl in red slippers to go with that Straw Man you've got there. 

For THOSE folks, do you REALLY think a DSO, with basic features often buried under multiple levels of menus and all of the complexities of digital sampling theory to learn in order to use properly, is a better choice when you're already trying to learn "This is an Amp, this is a Volt, together with Resistance, Inductance and Capacitance they make everything electronic go" fundamentals? Especially in a time when you can pick up a working CRO for $50-150 (often with warranty) on fleaBay ANY DAY of the week?

Arguing that you HAVE TO CHOOSE ONE OR THE OTHER is stupid; therefore any argument predicated upon that notion is similarly stupid.


mnem
    

That brings us back to my previous question. Where are the modern Keysight or R&S CROs? If CROs provide something that DSOs cannot, why aren't we seeing any serious contender producing them for that use? There are a plethora of niche use instruments that are sold for eye watering amounts of money because they do that one thing that nothing else can do, but CROs do not seem to be in that group.

[Brumby]

If I were to introduce someone to the world of oscilloscopes, I would start off with my Hitachi 2 channel 15MHz CRO.

Doesn't mean I will dissuade them from getting a DSO.



Now - please - let's walk away from this pointless haranguing ... or I'll start posting pics of my DSO138!

[bd139]

Dude... you need a Tin Woodsman, a Cowardly Lion and an impertinent Teenage Girl in red slippers to go with that Straw Man you've got there. 

For THOSE folks, do you REALLY think a DSO, with basic features often buried under multiple levels of menus and all of the complexities of digital sampling theory to learn in order to use properly, is a better choice when you're already trying to learn "This is an Amp, this is a Volt, together with Resistance, Inductance and Capacitance they make everything electronic go" fundamentals? Especially in a time when you can pick up a working CRO for $50-150 (often with warranty) on fleaBay ANY DAY of the week?

Arguing that you HAVE TO CHOOSE ONE OR THE OTHER is stupid; therefore any argument predicated upon that notion is similarly stupid.


mnem
    

That brings us back to my previous question. Where are the modern Keysight or R&S CROs? If CROs provide something that DSOs cannot, why aren't we seeing any serious contender producing them for that use? There are a plethora of niche use instruments that are sold for eye watering amounts of money because they do that one thing that nothing else can do, but CROs do not seem to be in that group.

No one wants them. As I said earlier, if I was running a business I’d use a DSO.

Also a point: when you have no scopes to start with, and that may be because you have an empty bench to fill at your company or university or home, then you tend to have to make the transition to having a scope. At that point the cost benefit of a DSO is much better.

At the bottom end, a DS1054Z is perfectly fine for most noddy industrial and personal users. Even going back to my short spell in industry, we had an inferior 100MHz DSO on bench. The nice scopes were pooled. Nice scopes being some 7000’s which were indication only and some high end HP.

CROs in 2018 are 100% dead. Apart from those of us who still like them. And that’s fine.