Author Topic: Questions on some older used Scopes and Probe Rec's  (Read 3558 times)

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Offline FulmirTopic starter

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Questions on some older used Scopes and Probe Rec's
« on: July 06, 2022, 11:28:39 pm »
I'm putting together a home hobbyist/enthusiast electronics lab and I've been poking around at Oscilloscopes. It seems like there are some decent deals around at the moment so I'm looking at picking something up but I wanted some advice and input on value for money and what actually makes sense to buy at this stage.

For some context, I'm currently messing around with digital signals in the sub-50MHz range, but I also have a strong tendency to chase shiny ideas and projects right out of the capability of my current equipment (no matter what the project is, not just electronics...  ;D), and often it ends up where if I can't do the next thing I lose interest entirely for a while, so I'm looking at something with some leg room to take on more ambitious projects.

Budget is $500-ish, color screen is pretty much a must, and I'm looking for good price to performance. For example I started out looking at older Tek scopes, but it's either $2-300 for a fairly basic 100MHz scope, or over $500 for a 1-200MHz scope with only decent-ish features and probably something failing self-test. So Tek is sort of out, barring a fantastic deal. I'm also not looking for anything I have to crack open just to get working barring very simple parts replacement or cleaning. Project equipment can come later, for now I want something that more or less just works. (like, I don't want to replace every SMD cap on an old Tek scope...)

I've been looking at older Lecroy scopes, since if you're willing to replace some knobs and/or broken plastic bits they seem pretty good value for money, and a great big color screen with customization options, which is great for my poor addled eyeballs and brain.

Specifically I've found some good deals in my area on an LT342 and an LC554DL, the former comes with one PP006 probe and is in great physical condition, the latter comes with itself, a cracked bezel, a broken floppy drive, and two missing knobs. Both are barely within my (rough) budget. Obviously the LC is a lot more Scope, but also no probes and while both are guaranteed to have basic functions I don't have a ton of info in either one. Also I'd have to buy probes to test the LC scope in case it has some issue.

Anyone have any other recommendations for Scopes to look at besides the older Lecroy models, or recommendations on either of those two models at ~$5-600 USD?

Any big used TE sites/vendors to avoid for this sort of thing? (I already know that stuff listed on the Bay is Buyer Beware a lot of the time, but I know what to look for there)

Also, any recommendations for used/budget probes to grab, for a Lecroy or otherwise? Not really looking for active probes at the moment, but recommendations for decent general use passive probes for various applications would be great! I've tried digging through various searched up threads on probes but while there's a lot talking about specific probes, or probes in a specific frequency class, I haven't found much in the way of "this is a good probe/probe class to have on hand"

EDIT: Yes, I've already looked at the options for buying new under about $500 and I'm not really that interested absent a really compelling case that I won't need anything more for the next 5+ years. Yes I know they can be hacked, yes I know they come with probes. I'd rather get something a bit better used, even if it's a bit old now. Besides there's something kind of satisfying about a beefy piece of equipment that you can crack open and fix if needed.
« Last Edit: July 07, 2022, 03:35:32 am by Fulmir »
 

Offline bayjelly

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Re: Questions on some older used Scopes and Probe Rec's
« Reply #1 on: July 07, 2022, 12:20:29 am »
Honestly I'm not sure old scopes are worth it. From what I have seen they tend to be not that much cheaper even though technology moved on significantly since.

A scope is one of the primary tools in electronics. You can definitely find something new, decent in the $500-$600 range, and you can get something really good if you adjust your budget to, let's say, 3-4x as much.

I personally started out with a $300-$400 Siglent scope as my first digital scope, this one, which fit my student budget at the time. That was 10 years ago or more (as you can see it's not available anymore), but even back then that got me a great tool that was perfectly adequate for what I was doing at the time. 70MHz, 2 channels.

Years later, I started to hit the limits of my scope. 2 channels wasn't always enough (although I have to say, the majority of the time it still is), larger memory would have been nice, as well as a better FFT function (even better if it can also do Bode plots including phase), protocol decoding, a graded intensity display (I would really miss that now)... so I got an R&S RTB2004 instead, packed with options since there was a bundle at the time at least.

It did make a difference. The scope is a joy and I regularly find myself using features that I didn't even really know about before purchasing it. It's not just enhanced capabilities, it's nicer to use, too. And even though in a lot of situations my old scope would still have been sufficient, in the plenty cases where it would not be, or only awkwardly so, it's very nice to have a higher class scope available.

But again, the $300-$400 scope did its job fine for years, and looking at eBay I could apparently still resell it for at least close to the original price (but I'm giving it to a friend who's learning instead). I guess what I'm saying other than to already consider a higher class scope if you can afford it, have you considered looking at what's available new given your stated budget?
 

Offline EE-digger

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Re: Questions on some older used Scopes and Probe Rec's
« Reply #2 on: July 07, 2022, 02:44:14 am »
Lecroy's I've used (later Wavesurfer 3054Z) had poor interface, arrogant support (from tech mouth:  "it's a low end scope, you can't expect much")

Tek fan for decades but major Agilent/Keysight convert.  Older Tek digitals (i.e. 3xx, 4xx) were garbage.  TDS784D or the like are powerful but the UI is long in the tooth.  Later Teks, I don't like a common knob for many multiple functions.  Keysight is still keeping position, scale controls on a per channel basis but may have changed on latest offering.

Lecroy probes - orphans

Tek probes - bargains for their active probes (adapter available for Tek to Agilent but not cheap), some good passive probes (500MHz passive workhorse, the P6139)

Agilent/Keysight probes - expensive in the used market, frequently large and clumsy next to their Tek equivalents (like the 1.5GHz P6245 active v N2795x is like $190 vs > $1k)

For your budget, best bet is probably the Rigol 1054Z (check the model) with function gen and serial decode.  I've bought about 8 of them in the past for lab techs, mostly very happy.  Screen is on the small size for my aging eyes.

Get your budget up and you can target a Agilent/Keysight DSOX3014A, simple hack gets you the function generator (wavegen, which is a function and arb generator), and all other options.

The Keysight 3000A or T support their auto probe (lite version).  The 2000A should be avoided if you ever need the auto probe interface.

added - almost forgot one HP/Agilent scope which is now cheap and always gave me a warm and fuzzy feeling is the 54622D series.  It's an MSO, 100MHz, nice green screen, always gave a good representation.  Makes older Tek look like the garbage I mentioned.

and well under $500  :) :) :)
« Last Edit: July 07, 2022, 02:48:09 am by EE-digger »
 

Offline Fungus

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Re: Questions on some older used Scopes and Probe Rec's
« Reply #3 on: July 07, 2022, 02:49:05 am »
Do NOT get an old green-screen 'scope. Just don't.

With that budget you can get a full featured 4-channel DSO complete with four brand new probes. It will have a warranty and occupy a fraction of the space.

I'd choose between:
a) https://www.tequipment.net/Instek/GDS-1054B/Digital-Oscilloscopes/
b) https://www.tequipment.net/Siglent/SDS1104X-E/Digital-Oscilloscopes/

The Instek has better user interface, the Siglent is more powerful.
 

Offline EE-digger

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Re: Questions on some older used Scopes and Probe Rec's
« Reply #4 on: July 07, 2022, 03:03:57 am »
They can be had at very low cost (even $200-ish) but I agree with you on the models you linked to.
 

Offline FulmirTopic starter

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Re: Questions on some older used Scopes and Probe Rec's
« Reply #5 on: July 07, 2022, 03:23:27 am »
Honestly I'm not sure old scopes are worth it. From what I have seen they tend to be not that much cheaper even though technology moved on significantly since.

A scope is one of the primary tools in electronics. You can definitely find something new, decent in the $500-$600 range, and you can get something really good if you adjust your budget to, let's say, 3-4x as much.

...

...I guess what I'm saying other than to already consider a higher class scope if you can afford it, have you considered looking at what's available new given your stated budget?


Something equivalent to the old 500MHz Lecroy scopes is 5k+ bought new right now, and I don't think it's even possible to find the things on the hobbyist secondary market, and besides that I'm not really after spending 2k+ on one piece of equipment right now when I can grab something a lot cheaper and more capable.

I have looked at what's available in my price range new and I'm just not that impressed. I know they're perfectly capable and very impressive scopes for what they are, but they don't seem to leave much room to grow if I want to start messing around with higher frequency stuff. They're certainly *lighter*  :-DD and probably a bit more reliable, but I know that buying old used equipment like this means I might have to crack it open and mess with it at some point. I also know that's possible though, and the age means that there's a lot more repair and modification documentation available, which appeals to me a fair bit as well.

Do NOT get an old green-screen 'scope. Just don't.

With that budget you can get a full featured 4-channel DSO complete with four brand new probes. It will have a warranty and occupy a fraction of the space.

I assure you, I'm not getting an old green screen scope, that's part of why I'm looking at the Lecroy's  :-DD I might get one eventually for nostalgia or something, they're what I learned on after all, but no, not interested in those.

The space isn't a huge issue for me at the moment with my setup. I have a decent sized workbench with an overhead shelf and no need for portability. The only space it would really save me is in width, and that's only like 3-4 inches.

The probes are somewhat attractive, but I'm not sure it's worth it. Also both Lecroy scopes have bigger screens. They're not as pretty, but they're pretty serviceable, and I can do an LCD swap at some point in the future.
 

Offline FulmirTopic starter

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Re: Questions on some older used Scopes and Probe Rec's
« Reply #6 on: July 07, 2022, 03:32:23 am »
Lecroy's I've used (later Wavesurfer 3054Z) had poor interface, arrogant support (from tech mouth:  "it's a low end scope, you can't expect much")

Tek fan for decades but major Agilent/Keysight convert.  Older Tek digitals (i.e. 3xx, 4xx) were garbage.  TDS784D or the like are powerful but the UI is long in the tooth.  Later Teks, I don't like a common knob for many multiple functions.  Keysight is still keeping position, scale controls on a per channel basis but may have changed on latest offering.

Lecroy probes - orphans

Tek probes - bargains for their active probes (adapter available for Tek to Agilent but not cheap), some good passive probes (500MHz passive workhorse, the P6139)

Agilent/Keysight probes - expensive in the used market, frequently large and clumsy next to their Tek equivalents (like the 1.5GHz P6245 active v N2795x is like $190 vs > $1k)

For your budget, best bet is probably the Rigol 1054Z (check the model) with function gen and serial decode.  I've bought about 8 of them in the past for lab techs, mostly very happy.  Screen is on the small size for my aging eyes.

Get your budget up and you can target a Agilent/Keysight DSOX3014A, simple hack gets you the function generator (wavegen, which is a function and arb generator), and all other options.

The Keysight 3000A or T support their auto probe (lite version).  The 2000A should be avoided if you ever need the auto probe interface.

added - almost forgot one HP/Agilent scope which is now cheap and always gave me a warm and fuzzy feeling is the 54622D series.  It's an MSO, 100MHz, nice green screen, always gave a good representation.  Makes older Tek look like the garbage I mentioned.

and well under $500  :) :) :)

I'm not too worried about support outside of this and similar forums as those scopes haven't been supported for over 10 years. Also the UI on older Lecroy scopes was completely different and, based on what I'm seeing from some quick googling, possible better than what their scopes show today.

I'm not quite sure what you mean by "orphan" probes. I know their active probes aren't really going to be compatible with anything else, but I'm not really looking at active probes right now. Well outside my budget or needs at the moment.

I've already looked at Rigol, Siglent, Instek, and the rest of the budget scopes available today and I think I'd rather get something more technically capable and a bit older.

That HP/Agilent scope looks great, but the all-green screen is a big no for me. As noted, my eyes and brain are not always great, and differing colors reduce the chance I'm going to miss-see something and go chasing wild geese for hours, or worse break something based on a bad read.
 

Offline nctnico

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Re: Questions on some older used Scopes and Probe Rec's
« Reply #7 on: July 07, 2022, 07:46:08 am »
I've already looked at Rigol, Siglent, Instek, and the rest of the budget scopes available today and I think I'd rather get something more technically capable and a bit older.
That is the problem. The older stuff is only interesting if you needs lots of bandwidth. The lower end scopes from GW-Instek, MicSig or Siglent (I'd skip Rigol!) run circles around the older oscilloscopes in every way.
« Last Edit: July 07, 2022, 07:50:10 am by nctnico »
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Offline FulmirTopic starter

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Re: Questions on some older used Scopes and Probe Rec's
« Reply #8 on: July 07, 2022, 04:34:09 pm »
I've already looked at Rigol, Siglent, Instek, and the rest of the budget scopes available today and I think I'd rather get something more technically capable and a bit older.
That is the problem. The older stuff is only interesting if you needs lots of bandwidth. The lower end scopes from GW-Instek, MicSig or Siglent (I'd skip Rigol!) run circles around the older oscilloscopes in every way.

Right, which is why I'm looking at Lecroy scopes, because they seem to come the closest to the modern scopes in terms of features. They have a large color screen and a *lot* of built in tools and analysis functions. They're not going to be as snappy as a modern scope and they're almost the size of a VW microbus, but I'm not particularly turned off by either of those things, and because they're so old fully unlocking their functions is cheap to free. Yes I know you can hack a lot of the newer low-end scopes, but I haven't done a detailed features comparison to see if one or the other wins. I just know the Lecroy seems to do quite well on features and that I can't magic bandwidth out of a Siglent (at least not past 1-200 MHz depending on model... >.> )

I fully admit I'm new enough at this stuff that I don't even know what I'd use some of these functions for, but like I said in the OP I want something with room for me to grow into more advanced and interesting projects without breaking the bank. I get that you and everyone else on here are busy, but if you could walk me through some of the thinking here I'd really appreciate it. Is there something specific that the Siglent (for example) offers that the Lecroy doesn't? Datasheet for reference: https://accusrc.com/uploads/datasheets/Lecroy%20554DL%20Datasheet.pdf
 

Offline bdunham7

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Re: Questions on some older used Scopes and Probe Rec's
« Reply #9 on: July 07, 2022, 04:37:25 pm »
I'm not quite sure what you mean by "orphan" probes. I know their active probes aren't really going to be compatible with anything else, but I'm not really looking at active probes right now. Well outside my budget or needs at the moment.

I've already looked at Rigol, Siglent, Instek, and the rest of the budget scopes available today and I think I'd rather get something more technically capable and a bit older.

I have a bit of experience renovating scopes of all types, others here have even more and I think we're all trying to tell you about the same thing, which is that while there are interesting and powerful older DSOs available, they aren't going to be in your budget.  At $500, unless you luck into a real deal, you are going to be sifting through old trash.  If you are very persistent and know what you are looking at, perhaps you will get lucky.  I haven't gotten that lucky yet.

Tek and HPAK models are all well-known and in demand.  $500 might get you an old TDS540 or something--but hey, it is 500MHz! LeCroy and Yokagawa might seem to yield a better bang-for-buck, but repairs are going to be more daunting simply because they are less common and less well-known.  A while back I was looking at a small lot of equipment that included a Yokogawa 8-channel scope, which would seem handy for your needs.  I'd never used one before and it did have some interesting features like separate windows for each trace, but overall it was fairly clunky and slow.  I don't recall the model or BW, but I don't think you are going to get one of those in working condition for $500, nor do I think it would be very good for general usage. 

As far as probes go, if you are talking about high-impedance 10X probes there's no real reason to get excited about any particular probe.  The main limiting issue is circuit loading and even the highly prized Tek P6139/A is still an 8pF load.  The "500MHz" is meaningless in real world applications and when I need to reduce circuit loading with a passive probe, I use a 100X version with lower capacitance, either an Aliexpress P2301C or an old Probemaster 4910, rated 'only' 300 and 200MHz respectively. 

Frankly I think that with your budget, specifying a 500MHz BW is going to kill you in terms of getting something with the other features that matter more for your foreseeable usage.

Edit:  To answer your question regarding specific models, the LT342 is an older version ETS scope, meaning the 500MHz BW is only for repeating signals.  The 500MSa/s means that its single shot BW is 100MHz or so.  The LC554DL has a very good feature set including valuable options you don't get on a $500 Siglent and in fact the features of modern Siglents are largely based on what the LeCroy offered back then, but it is a $3-5K scope if it is in very good condition. Unless you are very lucky, a $500 'deal' is going to be a box of junk.  Do you feel lucky?

« Last Edit: July 07, 2022, 04:52:05 pm by bdunham7 »
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Offline FulmirTopic starter

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Re: Questions on some older used Scopes and Probe Rec's
« Reply #10 on: July 07, 2022, 06:44:17 pm »
Okay, I think I'm convinced. I ended up digging into some of the slightly higher end scopes from Siglent and it seems I was a bit hasty in proclaiming 4k for something with equivalent or better functionality. The SDS2104X Plus can be hacked up to 500MHz and has most or all of the math features of the Lecroy, more memory depth, and the option of digital signals decoding provided I'm willing to either pay out the nose for a probe or build my own, and it runs about twice what I'd be paying for the LC554DL with shipping and probes. Plus the time spent fiddling to get it set up, and probably a small tower of cable adapters to get it connected to any computer built since 2005...  :-/O

For the record though I do feel pretty lucky in my ability to pluck good deals out of the ether, I've gotten pretty good at figuring out what looks like it may or may not work well, this is just my first oscilloscope.

The one I was looking at was this one BTW, I feel fine posting it since I don't think I'll be jumping on it... https://accusrc.com/product-Lecroy-544DL-10717

BTW are Accusrc and their Bargain Basement a decent source for used older equipment?
 

Offline Fungus

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Re: Questions on some older used Scopes and Probe Rec's
« Reply #11 on: July 07, 2022, 07:08:51 pm »
The lower end scopes from GW-Instek, MicSig or Siglent (I'd skip Rigol!) run circles around the older oscilloscopes in every way.

Yep, Rigol isn't price competitive any more, the price has been creeping up for some reason.

The Instek can be had for the same money and it's a better.

The Siglent used to cost about 50% more so a case could be made for getting a Rigol but now it's only about 20% more, so... nope.

I left out Micsig because they're kinda hard to get in the USA, but it's what I own and I'd get another one in a heartbeat if it breaks. Here in Europe they're a real bargain right now because Micsig just launched a new model so they're dumping old stock.

Oh, wait, there's none of the old ones left!  Too bad if you didn't get one.  >:D


( This is the new one )

 
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Offline G0HZU

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Re: Questions on some older used Scopes and Probe Rec's
« Reply #12 on: July 07, 2022, 08:42:40 pm »
I kind of went through the same dilemma a few days ago when my old HP 54825A Infinium scope started to become unreliable. If I couldn't fix it then I had the choice of buying something like one of the new Siglent HD scopes or to try and buy another used scope from HPAK. On ebay HPAK stuff seems to be really overpriced for the age/condition so bargains are hard to spot.

I really like the user interface of the Infinium both in terms of the layout of the controls and also the GUI. I also trust the measurement tools and it's easy to get data from it onto another PC. However, the limited memory depth means that this scope is of limited use for digital stuff, especially for SPI bus work for example.

I don't think I'd like to pay out £500-£1000 on a used HPAK scope because this usually buys something quite old like my old 54825A. Mine has the later factory upgrades so it is quite fast but it lacks the modern tools and features of the new stuff from Siglent. I think most people would be better off buying a new scope. I suspect part of the reason the HPAK stuff is so expensive is because it often may be in demand to replace faulty gear that has failed in an ATE rack at a manufacturing company. They have deep pockets and can't afford to halt the ATE for long to wait for a bargain or to rewrite the ATE program for a newer scope. So prices often remain firm for HPAK gear.

I managed to get my 54825A working again for the cost of a few capacitors in the PSU but I think I'll look at a new scope as a replacement soon. When the 54825A really became unreliable it happened a couple of days just before I really needed it for a project task.
 

Offline FulmirTopic starter

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Re: Questions on some older used Scopes and Probe Rec's
« Reply #13 on: July 07, 2022, 08:52:42 pm »
I don't think I'd like to pay out £500-£1000 on a used HPAK scope because this usually buys something quite old like my old 54825A. Mine has the later factory upgrades so it is quite fast but it lacks the modern tools and features of the new stuff from Siglent. I think most people would be better off buying a new scope. I suspect part of the reason the HPAK stuff is so expensive is because it often may be in demand to replace faulty gear that has failed in an ATE rack at a manufacturing company. They have deep pockets and can't afford to halt the ATE for long to wait for a bargain or to rewrite the ATE program for a newer scope. So prices often remain firm for HPAK gear.

The other half of it is that anything in decent condition for a good price gets snapped up fairly quickly. If you search by "Sold" on ebay you find that the "real" price of a lot of this stuff is well below what's actually listed currently. Like $500 scopes selling at Auction or even "Buy It Now" for $200-300, and some of the $1-2k stuff selling for $500-1k, though I'm sure some of that is also going to the bigger resellers who test, refurb, and maybe calibrate it and then post it back up for even higher prices.

I think the reason there was such a good deal on that Lecroy is a combination of the damaged bezel and the competition from the newer Siglent scopes. It just wasn't worthwhile for the reseller to go through and spruce it up when the competition is already $800-2k.
 

Offline G0HZU

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Re: Questions on some older used Scopes and Probe Rec's
« Reply #14 on: July 07, 2022, 09:10:49 pm »
Maybe try haggling for a good deal on one of the 100MHz Siglent scopes (and hack it?) and this would then mean you could search in slow time for one of the old 500MHz+ classics from HPAK or Lecroy for a very low price. Patience may be the key here.

 

Offline FulmirTopic starter

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Re: Questions on some older used Scopes and Probe Rec's
« Reply #15 on: July 07, 2022, 09:22:42 pm »
Maybe try haggling for a good deal on one of the 100MHz Siglent scopes (and hack it?) and this would then mean you could search in slow time for one of the old 500MHz+ classics from HPAK or Lecroy for a very low price. Patience may be the key here.

Part of the reason I wasn't that interested in those is lack of growth room and the relatively tiny screen. It looks like their more mid-range stuff (which is also hackable...  ;) ) fixes the screen and features issues.

I can afford it, I just didn't want to pay that much if it wasn't worth it. The fine folks here (plus a few IRL friends) have convinced me that it probably is worth it in terms of features and time not spent "setting up" a used scope. Seriously Siglent and the rest should pay some of you all commissions  ;D
 

Offline nctnico

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Re: Questions on some older used Scopes and Probe Rec's
« Reply #16 on: July 07, 2022, 09:28:55 pm »
Let me throw my commision out of the window then: seriously consider other brands as well. I have spend several k euro on Siglent equipment only to find out it didn't perform when the pedal needed to hit the metal. If you have the budget then be sure to look at higher priced stuff from Keysight, R&S, Tektronix, Yokogawa, etc. For starters; you'll find much more polished user interfaces based on decades of experience making test equipment.
« Last Edit: July 07, 2022, 09:31:02 pm by nctnico »
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Online tautech

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Re: Questions on some older used Scopes and Probe Rec's
« Reply #17 on: July 07, 2022, 09:31:38 pm »
Maybe try haggling for a good deal on one of the 100MHz Siglent scopes (and hack it?) and this would then mean you could search in slow time for one of the old 500MHz+ classics from HPAK or Lecroy for a very low price. Patience may be the key here.

Part of the reason I wasn't that interested in those is lack of growth room and the relatively tiny screen. It looks like their more mid-range stuff (which is also hackable...  ;) ) fixes the screen and features issues.
That's not the issue you might think it is if you have a PC on the bench to take advantage of these scopes inbuilt webserver.
How large did you say you'd like the screen to be Sir ?
Maybe 48" ?  :)
Below back in 2014 was the first I'd seen.



BTW, that was a SDS3000 DSO and a model we never saw in the west other than in LeCroy colors and even the updated 3000X was a LeCroy in the west too.
« Last Edit: July 07, 2022, 09:39:08 pm by tautech »
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Offline G0HZU

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Re: Questions on some older used Scopes and Probe Rec's
« Reply #18 on: July 07, 2022, 10:35:47 pm »
One other thing that I like about the 54825A is that it uses an old school front end using relay switched attenuators. This is a bit clunky but it does mean that the scope achieves a low trace noise on the most sensitive settings. A typical scope like this might have an impedance converter + preamp with a wideband noise floor of about 5nV/sqrtHz. So my scope should achieve a trace noise of 5nV x sqrt(500e6Hz) = 110uV rms on the lowest settings. It actually manages about 90uV.

This is a lot cleaner than some budget scopes. A lot depends on the way the scope front end is designed. I watched some of Dave's teardowns a while back and it's fairly easy to spot the scopes that will be very noisy just by looking at the way the front end is designed. Looking at the images in the teardown the Rigol 7000 scopes look to be quite poor here and I guess the same applies for the cheaper 5000 series. The low budget portable Tek scopes are similar. This would prevent me from buying a scope like this because the higher trace noise on the sensitive ranges would bug me.

I'm not sure how Siglent design the front end but I've read that they do have much lower noise on the most sensitive ranges compared to the Rigol scopes for example.

 

Offline bdunham7

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Re: Questions on some older used Scopes and Probe Rec's
« Reply #19 on: July 08, 2022, 12:45:09 am »
Part of the reason I wasn't that interested in those is lack of growth room and the relatively tiny screen. It looks like their more mid-range stuff (which is also hackable...  ;) ) fixes the screen and features issues.

If you don't have any experience with DSOs the $500 Siglent will have you 'growing' into it for some time before you figure out the bulk of what it can do.  And with the WiFi you can use the webserver for a large picture if you like, as well as hands-off operation of the scope.  200MHz is not a big limitation if you are only using 'normal' probes. 

If you aren't actually restricted to a budget of $500, the next-up Siglent SDS2104X+ with the logic probe set is a pretty good setup and you'll be growing into that for years. 
A 3.5 digit 4.5 digit 5 digit 5.5 digit 6.5 digit 7.5 digit DMM is good enough for most people.
 

Offline FulmirTopic starter

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Re: Questions on some older used Scopes and Probe Rec's
« Reply #20 on: July 08, 2022, 01:52:46 am »
If you don't have any experience with DSOs the $500 Siglent will have you 'growing' into it for some time before you figure out the bulk of what it can do.  And with the WiFi you can use the webserver for a large picture if you like, as well as hands-off operation of the scope.  200MHz is not a big limitation if you are only using 'normal' probes. 

If you aren't actually restricted to a budget of $500, the next-up Siglent SDS2104X+ with the logic probe set is a pretty good setup and you'll be growing into that for years. 

So, this may just be my learning style, but I tend to be less into "learn by feature" and more "learn by project" so if I want to do something and the scope physically can't do it then I'm just kinda stuffed. I'm more than happy to work through all the pre-requisite learnings to figure out how to do the thing I want to do with the equipment I have.

The $500 isn't a hard requirement, but I need to be able to justify the increased cost to myself compared to buying older equipment and just dealing with the teething pains or buying something super budget. I definitely don't want to go above the ~$1400 the SDS2104X is going to set me back, and that thing looks like all the scope I'm ever likely to need unless I decide to go completely off the deep end and make a side-gig out of refurbishing dead graphics cards or something...

The Wifi is a good point, since I do have a monitor on the bench already, but it'd still be nice to have the larger screen of the Plus version.

Let me throw my commision out of the window then: seriously consider other brands as well. I have spend several k euro on Siglent equipment only to find out it didn't perform when the pedal needed to hit the metal. If you have the budget then be sure to look at higher priced stuff from Keysight, R&S, Tektronix, Yokogawa, etc. For starters; you'll find much more polished user interfaces based on decades of experience making test equipment.

I think if I ever hit the point that this stuff won't serve my needs then I'll decide then if I want to spend the money on something more serious, used or new, but I don't really think that's going to be the case for a long while yet, unless I find a way to make this hobby self-funding anyways >.>

I'd love to be able to afford something like a brand new R&S or Yokogawa mid-ranged scope, but right now that's a hard no from me, I just can't justify that kind of money for a bit of a UI upgrade and a bit more performance on the far ends of the bell curve.

If you have some recommendations more in line with the 2104X or X Plus then please by all means, or even just some examples of places those scopes might trip me up. I'd love to learn, but I can only stretch the budget here, not break it...
 

Online tautech

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Re: Questions on some older used Scopes and Probe Rec's
« Reply #21 on: July 08, 2022, 03:10:38 am »
If you have some recommendations more in line with the 2104X or X Plus then please by all means, or even just some examples of places those scopes might trip me up. I'd love to learn, but I can only stretch the budget here, not break it...
SDS2104X are an older EOL series and 4ch versions are no longer available.
https://siglentna.com/digital-oscilloscopes/sds2000x/

Note the recommendation: See SDS2000X Plus for replacement

SDS2000X Plus are in another league of instrument, I've owned and extensively used them both.
Touch and mouse control, webserver, VNC, Bode plot and so much more.
As you have found in your research, they've been a very popular seller over the last year or so as they can't be touched at this price point. Even LeCroy consider them good enough to have as their lower end range T3DSO2000A.

Happy hunting and anything in particular you need know just ask.



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Offline FulmirTopic starter

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Re: Questions on some older used Scopes and Probe Rec's
« Reply #22 on: July 08, 2022, 04:12:42 am »
Ah, okay, I can see that the naming scheme on these things is going to be the death of me...  :-DD

I meant the X-E, apparently. But yeah, the lowest end 4 Channel X Plus seems like the best deal, especially with the option to, uh, "liberate" some of the higher end features via "adjustments" >.>

Any particular problems or quirks with it I should be aware of? Any chance prices on these things are about to spike up due to supply chain etc? >.> :-/O
 

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Re: Questions on some older used Scopes and Probe Rec's
« Reply #23 on: July 08, 2022, 05:30:27 am »
On phone so replies will be nothing flash sorry.
First there are zero 2000 series 4ch X-E’s.
Unfortunately all specials on X Plus are now resigned to 2021 specials but I know of no impending price hikes.  :phew:
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Offline Performa01

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Re: Questions on some older used Scopes and Probe Rec's
« Reply #24 on: July 08, 2022, 08:23:15 am »
I'm not sure how Siglent design the front end but I've read that they do have much lower noise on the most sensitive ranges compared to the Rigol scopes for example.

They do it old-school instead of cheap-arse, they are not like Tek who make do with one single relay for the entire analog channel.

In a 2000-series Siglent, there are no less than five relays per channel: AC / DC / GND, 50 ohms, two 20 dB input attenuators.

Even the cheap SDS1000X-E has a proper input section with two relay operated 20 dB attenuators.
 
The noise of an SDS2504X HD (true -3 dB bandwidth = 570 MHz) at 1 mV/div with open input (1 meg or 50 ohms) is less than 80 µVrms.
See attached screenshot SDS2504X HD_Noise_2Ch.

EDIT: added another screenshot to demonstrate the noise spectrum: SDS2504X HD_Noise_1mV_500MHz_L
« Last Edit: July 08, 2022, 08:27:22 am by Performa01 »
 
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