Recommendation on selecting a used oscilloscope?

[nathankwan]

Hi guys, I must admit I am kind of obsessed with good scopes... So please try to focus less on the actual need (I'm working below 100MHz so a TDS220 should be enough in that case, but I just want as much performance as possible as long as the price is acceptable)

I would like to have an affordable used scope, with relatively good performance and endurance. I've done some digging and got this list:

> TDS3000B series, or more precisely TDS3014B, with easy upgrade through ethernet.
> Lecroy wavesurfer 44Xs (or similar), would also like to upgrade sample rate but just don't know how (I've seen someone succeeded).
> TDS784D/794D, just like its color CRT...

But I also have concerns about each one above:

> TDS3000 series have shallow memory depth and crazy-low waveform refresh rate, but their price are around $500 in where I am.
> I love Lecroy's enclosure size and Windows OS, wfm refresh rate is high, but expensive (around $1500, old 7300A are cheaper, but so heavy).
> CRT attracts me, memory depth and wfm refresh are fair, but too heavy, and only 1GS/s when all channels on, etc...

I came here to see if anyone can share some other models that I'm not farmiliar with, like Agilent/Keysight, R&D, Siglent(I don't really like), RIGOL(I don't like either),  YOKOGAWA etc...

[tautech]

Hi guys, I must admit I am kind of obsessed with good scopes...

You and me both.

I came here to see if anyone can share some other models that I'm not familiar with, like Agilent/Keysight, R&D, Siglent(I don't really like), RIGOL(I don't like either),  YOKOGAWA etc...

Please tell why ? 

My first DSO was a Tek TDS2102B (now busted) and later had my hands on TDS210 and TDS10**B I don't remember which model, 60 MHz IIRC but they were both busted and then repaired and sold.

The earliest Siglents we had 11 yrs ago were easily as good DSO's as the Tek's and in my experience have proven to be more reliable.
You should take a long hard look at SDS804X HD ......

[Fungus]

I came here to see if anyone can share some other models that I'm not farmiliar with, like Agilent/Keysight, R&D, Siglent(I don't really like), RIGOL(I don't like either),  YOKOGAWA etc...

The new 12-bit Rigols/Siglents are far better than anything you'll find second hand for the same price.

[pdenisowski]

The new 12-bit Rigols/Siglents are far better than anything you'll find second hand for the same price.

Having owned a bunch of different "hobbyist" oscilloscopes over the years: I agree completely that you will probably get a lot more bang for your buck just buying a new hobbyist scope versus buying a used scope.  Even scopes I bought new 10 years ago look pretty ... sad ... compared to what I could buy today for the same money.

Huge difference between buying a 20 year old multimeter and a 20 year old oscilloscope

[watchmaker]

^

[nctnico]

Hi guys, I must admit I am kind of obsessed with good scopes... So please try to focus less on the actual need (I'm working below 100MHz so a TDS220 should be enough in that case, but I just want as much performance as possible as long as the price is acceptable)

I would like to have an affordable used scope, with relatively good performance and endurance. I've done some digging and got this list:

> TDS3000B series, or more precisely TDS3014B, with easy upgrade through ethernet.
> Lecroy wavesurfer 44Xs (or similar), would also like to upgrade sample rate but just don't know how (I've seen someone succeeded).
> TDS784D/794D, just like its color CRT...

But I also have concerns about each one above:

> TDS3000 series have shallow memory depth and crazy-low waveform refresh rate, but their price are around $500 in where I am.
> I love Lecroy's enclosure size and Windows OS, wfm refresh rate is high, but expensive (around $1500, old 7300A are cheaper, but so heavy).
> CRT attracts me, memory depth and wfm refresh are fair, but too heavy, and only 1GS/s when all channels on, etc...

As others noted, for $500 you can buy a new DSO. Even a super low-cost Fnirsi is likely a better buy as a daily driver for measuring sub 100MHz signals.

The second hand scopes you listed are only interesting if you need >500MHz bandwidth OR advanced analysis. A Lecroy 7300A is a great scope for signal analysis (I have one myself) but not very suitable as a daily driver.

A lot depends on what you need though. If you are only working on analogue circuits, any DSO will do.

[nathankwan]

Hi guys, I must admit I am kind of obsessed with good scopes...

You and me both.

I came here to see if anyone can share some other models that I'm not familiar with, like Agilent/Keysight, R&D, Siglent(I don't really like), RIGOL(I don't like either),  YOKOGAWA etc...

Please tell why ? 

I haven't used any of Siglent scopes but I recall people around in the lab during my graduate time were mentioning about the reliability and accuracy issues (and strange bugs, slow response time in UI, etc.)... But that's more than 10 years ago, I believe these days Siglent scopes must have developed, but those words do have a long impact...

I'll take a look at SDS804X HD

[BillyO]

(I'm working below 100MHz so a TDS220 should be enough in that case, but I just want as much performance as possible as long as the price is acceptable)

Strictly analog signals without risetimes of 3.5ns or less?

I build little computers and use microcontrollers that operate at under 20MHz, however they make signals with frequency components near the GHz range.  You'd be amazed at what more you can see on these tings with a 600MHz scope over what you see with a 100MHz scope.  All sorts of things that can and do cause trouble.

[David Hess]

But I also have concerns about each one above:

> TDS3000 series have shallow memory depth and crazy-low waveform refresh rate, but their price are around $500 in where I am.

I am not sure where the "crazy-low waveform refresh rate" comes from.  The specifications list 400 waveforms per second in normal mode and 3,600 in fast trigger mode.  Tektronix considers this series to be digital phosphor oscilloscopes.  Performance down to 15 or 30 waveforms per second is still real time, albeit not so good for capturing rare glitches.  These are also "real time" oscilloscopes as Tektronix uses the term so memory and sample rate are not shared between channels.

Memory depth is 10,000 point maximum, but these oscilloscopes have a real delayed sweep and trigger so this is not as much of a limitation as it would be in a more modern instrument without them.

I agree with nctnico that for that price, you are likely better of buying a less expensive Siglent DSO.

[moerm]

Hi guys, I must admit I am kind of obsessed with good scopes...

Define 'good', not to quarrel with you but to better understand what your priorities and desires are.

I would like to have an affordable used scope, with relatively good performance and endurance. I've done some digging and got this list:

> TDS3000B series, or more precisely TDS3014B, with easy upgrade through ethernet.
> Lecroy wavesurfer 44Xs (or similar), would also like to upgrade sample rate but just don't know how (I've seen someone succeeded).
> TDS784D/794D, just like its color CRT...

But I also have concerns about each one above:

> TDS3000 series have shallow memory depth and crazy-low waveform refresh rate, but their price are around $500 in where I am.
> I love Lecroy's enclosure size and Windows OS, wfm refresh rate is high, but expensive (around $1500, old 7300A are cheaper, but so heavy).
> CRT attracts me, memory depth and wfm refresh are fair, but too heavy, and only 1GS/s when all channels on, etc...

I came here to see if anyone can share some other models that I'm not farmiliar with, like Agilent/Keysight, R&D, Siglent(I don't really like), RIGOL(I don't like either),  YOKOGAWA etc...

"Windows OS" in my view is not a plus but rather a major minus, especially for an everyday go-to scope.

As you seem to want a reasonably high WUR scope with attractive features and at a low-ish price I'd go for a Siglent without even a second thought. You said you don't like Siglent but I think you should consider the fact that back then they were relatively new. Nowadays however they have lots of experience and are a good choice and btw. also a choice that is likely to last and serve you well for many years.

Re 'LeCroy': I also was attracted but recently I learned that, at least as a private or small customer you are unlikely to get support but rather a cactus in your rear from them.
Also note that to some degree Siglent can be seen as LeCroy-ish that is they produce some hardware for them and also seem to have a similar approach.

But again: Tell us what you mean when saying 'good' .

(edit: corrected stupid quoting mistake)

[points2]

Hi,
"used scope" ?
here is my "tiny" experience :

1. like the other mates above that said : a "new" scope is far better than any oldies.
I agree completly... given that any oldies have a no/tricky connections to PC, not like with any "new" => useless in 2024 ! :-)
WTF buying an old blulky box that can measure any stuff within : 500MHz max & 2GS/s...
That range of scope = any "smartphone" => the last on the market is far away the perf. of any oldies 

2. OLD = COOL & CHEAP... if... your need is peculiar.
given any scope, the price is related to GS/s & BW (my 2 cents...).
Lucky me, I managed to buy a sampling scope at dumped price (old-stock) ; it's an old scope, but it can do measurement that NO-NEW-DSO can do => in that case => "old" = OK given market prices of these peculiar scope.

[nathankwan]

But I also have concerns about each one above:

> TDS3000 series have shallow memory depth and crazy-low waveform refresh rate, but their price are around $500 in where I am.

I am not sure where the "crazy-low waveform refresh rate" comes from.  The specifications list 400 waveforms per second in normal mode and 3,600 in fast trigger mode.

I think fast or slow is relative, and it's my bad not pointing out my level of reference.

I got a TDS644A($400 w. SPC failing but little DC offset) and a TDS784C($450 fully functional) years ago as my first attempts to develop my own electrionic lab. 784C have refresh rate up to 400K wfm/s, 644A should be 100 wfm/s(possibly limited by the slow ADC since those samples are stored in analog CCDs to achieve cheap 2GS/s). These bulky scopes formed my upper and lower bounds on refresh rates.
However these TDS600/700 are released at the 90s, so I think a rather high-end scope released in 2008 should have reasonably high refresh rate (just to be clear this is only describing my feeling about hardware developments over the years), so knowing it's only around 3000wfm/s gives me the impression of "crazy-low".

Again, I love scopes, I am greedy and want more performance, that's it.

I like to put scopes into different categorys using their sample rates:
CAT I-> ~1GS/s scopes - like TDS220, cheap, handy and everywhere, If I want one of these, I'll buy a new one as they are definitely far better than any used old-timers.
CAT II-> 2.5GS/s~5GS/s - like TDS3000/MSO3000, mainstream, around the edge of my financial power, If I want one of these, I'll be choosing among a) a new CAT II scope, like MDO34-200/MDO3024, or b) a used CAT III scope, like Lecroy WS104Mxi-A or DPO/MSO4104B.
CAT III-> 10GS/s above - like DPO7000C, high-end, If I want one of these, I'll have to buy a used one. THIS IS WHY I CAME HERE.
CAT IV-> over 40GS/s, far from cheap, totally impractical to purchase for personal use.

(also I found old tek 7854/7904 VERY attractive........)

[coromonadalix]

@nathan as a good resume,

as an hobbyist at home

i tried some old fluke 100Mhz portable scope ....  works but ...

tried the new cheap Hantek 2d15 model. was ok but basic ...

i work with old turd like  TEK 7404 and 7254b, yeah yeah  Windowish  platforms,   if they are well maintained they work, until an hard drive crash or the famous dallas clock dies, if you did not saved the power pc settings   it may take a while to restart them

work with 2s Siglent sds 1000x,   hacked to 200mhz   simple and fun to use

work with a Rigol, hacked too to 200mhz    works fine but like the Siglent a little more,  but with scripting / python .. Siglent is way better

work too with a Picoscope 3406d, practical to say the least,   but man   very very expensive 3400$ CAD  outch

wanted a used Lecroy 1 - 2 ghz  models, but as mentioned,  you're almost out of luck if it break,  some good threads here ... unless you find a clean one and self test passed at a good price ??

oldies like tds 5k or 6k  mmmm  you have to see all the spc tests etc ... before even buying one, same for 7 k series,  but 7k series are biiiiiiig heavyyyyyy bulkyyyyyy

we have evaluated the new Siglent SDS 7k series,  my boss  is hesitating ... but man this scope was  NIX based  and runned darn well for the tests we needed / done. having 27k$$ CAD i would have bought it right away  loll

Agilent  mmmmmm not,   now they don't deal with single individual ...  not new for sure,  maybe some Infinium series


in the end  good ol scope depends of your need,   but if you compare modern things with the oldies ... you'll be deceived in some ways,  you have to know your needs for sure,  and know how to deal with them if they break ??

my 2 cents


still some good ol series of tek  tds 7xx series up to 1 gig,  you can do some BW upgrades ...   

tds3k serie,  way overpriced for what they offer, but BW upgradeable too



and now the race between Rigol and Siglent  give us  more for the money   ...    with easy BW  upgrades  cough cough  loll  same for many items, sig gens etc ...

[nathankwan]

Thanks for the posts guys, I think putting my tek complex aside, it's the time of Siglent.

[figgie]

Re 'LeCroy': I also was attracted but recently I learned that, at least as a private or small customer you are unlikely to get support but rather a cactus in your rear from them.
Also note that to some degree Siglent can be seen as LeCroy-ish that is they produce some hardware for them and also seem to have a similar approach.

So I think there is some region issue on support for Lecroy.

I am a TINY customer. Like hobby MAYBE going to small business size along with used equipment budget BUT i am located in USA.

I have had interactions with Lecroy directly and they have been super responsive to me on some key issues, some software notes and calibration procedures. IN all cased they were responsive. 1 time it did take them a bit as they were researching on their back end on some items i reported.

Mind you i am using a Lecroy Waverunner HRO 66zi circa 2012 (bought used from ebay for $1k flat since it was "erroring" out, long story short, there was numerous bad sectors on the OEM 160GB Western Digital Black drive that I fixed and then clonded over to 1TB corsair SSD). Currently it is running MAUI 10.7 without any issues.

You mileage will vary based on region and if you are a business or not.

[stj]

dont buy "old" used scopes if you just want to use them.

i am in the prcess of replacing around 80 capacitors in a scope made in 1996
26 of them are SMD and ALL have leaked!

[David Hess]

dont buy "old" used scopes if you just want to use them.

i am in the prcess of replacing around 80 capacitors in a scope made in 1996
26 of them are SMD and ALL have leaked!

You should have bought an older scope.

[points2]

@nathan as a good resume,
as an hobbyist at home
i tried some old fluke 100Mhz portable scope ....  works but ...
tried the new cheap Hantek 2d15 model. was ok but basic ...
i work with old turd like  TEK 7404 and 7254b, yeah yeah  Windowish  platforms,   if they are well maintained they work, until an hard drive crash or the famous dallas clock dies, if you did not saved the power pc settings   it may take a while to restart them
work with 2s Siglent sds 1000x,   hacked to 200mhz   simple and fun to use
work with a Rigol, hacked too to 200mhz    works fine but like the Siglent a little more,  but with scripting / python .. Siglent is way better
work too with a Picoscope 3406d, practical to say the least,   but man   very very expensive 3400$ CAD  outch
wanted a used Lecroy 1 - 2 ghz  models, but as mentioned,  you're almost out of luck if it break,  some good threads here ... unless you find a clean one and self test passed at a good price ??
oldies like tds 5k or 6k  mmmm  you have to see all the spc tests etc ... before even buying one, same for 7 k series,  but 7k series are biiiiiiig heavyyyyyy bulkyyyyyy
we have evaluated the new Siglent SDS 7k series,  my boss  is hesitating ... but man this scope was  NIX based  and runned darn well for the tests we needed / done. having 27k$$ CAD i would have bought it right away  loll
Agilent  mmmmmm not,   now they don't deal with single individual ...  not new for sure,  maybe some Infinium series
in the end  good ol scope depends of your need,   but if you compare modern things with the oldies ... you'll be deceived in some ways,  you have to know your needs for sure,  and know how to deal with them if they break ??
my 2 cents

still some good ol series of tek  tds 7xx series up to 1 gig,  you can do some BW upgrades ...   
tds3k serie,  way overpriced for what they offer, but BW upgradeable too
and now the race between Rigol and Siglent  give us  more for the money   ...    with easy BW  upgrades  cough cough  loll  same for many items, sig gens etc ...

well...
I may be wrong but, as I said above :
why bother in testing / having any scopes that perform within the same range of "sample rate" & BW

Simple fact : "same range of "sample rate" & BW" => we end up to a question of "taste" vs the interface, simply because the results are equal.