Author Topic: Owon SDS7102 or Tektronix TBS1062 or TDS1002  (Read 21925 times)

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Offline Hydrawerk

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #25 on: May 13, 2013, 08:26:29 pm »
No. Old Tek 24xx is not a storage scope. DS2000 is better IMHO.
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Offline luca1000

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #26 on: May 13, 2013, 08:39:12 pm »
Quote
No. Old Tek 24xx is not a storage scope. DS2000 is better IMHO.

For me only precision , accuracy , low noise and general performance are important for me.
 

Online nctnico

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #27 on: May 13, 2013, 11:42:51 pm »
I vote for the new DSO. The major advantage is that you can stop a waveform, save it as a picture and also view low frequency signals.

My experience with old analog scopes isn't very good. Even though some are made around simple parts those simple parts have become obsolete a long time ago. Not to mention that high end models often have custom chips inside them. If those go bad its the end of the story. Another problem is bad contacts in switches and pots. Nothing is more annoying than having to wiggle a switch to see whether the signal is noisy or the switch went bad again. The Tektronix 2200 and 2400 series are nice scopes but they are old and not very service friendly due to their compact build. If you get one from the early eighties then you are looking at a close to 30 year old instrument chuck-full of digital electronics which can go bad any time.
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Offline rf-loop

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #28 on: May 14, 2013, 05:02:14 am »
I have Tek 2246A in daily use. Nearly daily use Tek 2465A or B (which one is more near in what time)

Old gears, but good and very extremely reliable. And what best, what ever speed you turn, no aliasingn never. Allways really real time, what you see you can trust it is really there. Resolution is far better than 6.5 digit ADC digital scopes. And they are fast in use. No need play any games, just do work and there time is money. Of course there is area where digital scope beat 1-0 old analog but it is other case.
And 2465 depends of model you get 350 - >400MHz BW.  And depend options you get nice features. 
But all electronics have parts what can fail. Hybrids fails if you just open case and use it long time without service fan or if old fan stop and you get baked hybrids.

Look carefully what you buy, you can buy one nightmare or you can buy perfect reliable tool for many years... perhaps more lifetime still than new cheap digital "onetime use". These new units are designed for short lifetime.

Good analog oscilloscope is good. If someone tell something other perhaps he/she do not have enough experience.
« Last Edit: May 14, 2013, 05:05:49 am by rf-loop »
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Offline Wuerstchenhund

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #29 on: May 14, 2013, 05:23:07 am »
Wuerstchenhund - you bought a Chinese DSO? Say it ain't so!  ;)

I know, every time I walk into my home lab I am reminded that I really did buy one  :scared:

But for the price (£209 incl. shipping) it's quite good, with 1GSa/s (single channel mode), 32k sample memory (the 2MB would have cost £40 more for which I was too cheap), a very silent temperature controlled fan, and up to 2000 (or was it 3000?) waveforms/sec (it doesn't have trig out so measuring it will be a bit more complicated). Apparently it also has a real-time recording facility directly to USB memory stick at a low sample rate, and it saves displayed waveforms to a CSV file which then can be loaded into a Siglent SDG1000 AWG to generate this waveform. I'll do a review as soon as I find the time.
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Offline Wuerstchenhund

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #30 on: May 14, 2013, 05:36:11 am »
I vote for the new DSO.

+1

I'd not recommend an analog scope unless it is really, really cheap. No matter how good many of these scopes are, the fact is that the majority of them is probably close to the end of their useful service life. And at the end of the day, you want a scope that is reliable and not one that requires you to put more time into fixing your tools than into projects. And as ntnico says, many parts in these analog scopes are obsolete and often fetch insane prices if one of these rare parts turn up on the 2nd hand market.

One thing to remember is that you get what you pay for. If your budget only allows for a cheap Chinese scope then that's the level of quality and performance you get. It will not give you the lowest noise floor or the best performance. All these things cost money. There's no way around that.

I think for general audio work most DSOs should do fine.
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Offline luca1000

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #31 on: May 14, 2013, 06:38:02 am »
I think we speak too generally and this is too aproximative.

For opinion is better a real comparative with a specific model A and B.


Comparation (1)

New Owon SDS7102 (350 Euro)  VS Used good state Tektronix 2465 (250 Euro). Only performance is prioritare for me, not functions or features.

What is the best ??

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

Comparation (2)

New Rigol DS2072  (700 Euro)  VS Used good state Tektronix 2465 (250 Euro). Only performance is prioritare for me, not functions or features.

What is the best ??

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

Comparation (3)

New Tektronix TDS2012C  (1100 Euro)  VS Used good state Tektronix 2465 (250 Euro). Only performance is prioritare for me, not functions or features.

What is the best ??

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

I will use only few hours / years (I' am a hobbist my real work is software developer).

So the probability to break are not very high on my case.
« Last Edit: May 14, 2013, 06:40:15 am by luca1000 »
 

Online BravoV

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #32 on: May 14, 2013, 06:54:18 am »
............. Used good state Tektronix 2465 (250 Euro). Only performance is prioritare for me, not functions or features. .............

Hold on, not so easy, that 250 Euro is not enough if you're going to prioritize on getting the true performance out of that Tek 2465/B.

Even an "used" but working Tektronix passive probe that capable of reaching 350-400 Mhz in a "pair" might cost you > 100 Euro. Beside owning a good scope like Tek 2465/B but with cheap Chinese probe is pointless.

My 2 cents as Tek 2465B owner.

Offline PA4TIM

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #33 on: May 14, 2013, 07:05:41 am »
-1
I payed 900 euro for a brand new Rigol DS1102E, probes died within a year, after two years 2 buttons stopped working and a third just fell off. Measurement results were far off, jitter and noise was terrible. Just one plastic piece of stinking junk. I gave it away to a student I know.

I have many analog scopes, the oldest is from the 60's and all work without problems. But they can and will quit working one day. Like I said before, the 465 is more repair friendly and you do not need >100 MHz for audio.
But those modern DSOs too, only they do not wait 40+ years before they stop. Price has its downsides. You only can have the lowest price if you use the cheapest components and save wherever you can ( design, end-controll, production, calibration, warranty and parts)

Nico, i see no advantance for a DSO in audio ( like the TS said he needed it for) besides that, most amplifiers have rather high voltages and many Chinese scopes are limited to 30-50V direct input, so if you forget to switch your probe to 10X or by accident put it in 1X then your scope is toast. Do not try to measure a 500V anode voltage with a chinese probe and scope unless you have a good insurance.
I have analog scope plugins that I can use with a 1X probe and 500V easy.

I have a DSO and I enjoy the things it can do, I use my analog scopes or the things it can not do so good. But do not forget, th only reason we are stuck with only DSOs is price. A DSO is much more cheap to make with higher profits. If you make a 100, 200 and 300 MHz DSO you make one model and the software makes 3 out of them. You make a huge profit on the lower models. If you made three Analog scopes you needed three different CRTs and these become very expensive if frequency increases. The nicest solution were the hybrid scopes. Anlog and digital in one cabinet using a CRT. Once the future but to expensive compared to DSOs so they died a silent dead ( but they were much, much better)

Just look for a 465, for audio even a 10 MHz scope will do and you buy those under 50 dollar. Buy an other one if it should break. You can buy 4 a 5 for the price of a 2465

Hameg has a nice nd good 60 MHz DSO, i would prefer that over the Tek DSO
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Offline luca1000

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #34 on: May 14, 2013, 07:29:42 am »
if my signal is always < 1 Mhz and I have for example:

A anologue (2445) 150 Mhz

like this:

http://www.ebay.co.uk/itm/TEKTRONIX-2445-OSCILLOSCOPE-4X150MHz-/281095209240?pt=FR_YO_MaisonJardin_Bricolage_ElectroniqueComposants&hash=item4172948118


and I have 100 Mhz probe.

I need to buy other probe ?
« Last Edit: May 14, 2013, 07:31:50 am by luca1000 »
 

Offline Wuerstchenhund

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #35 on: May 14, 2013, 08:02:28 am »
But do not forget, th only reason we are stuck with only DSOs is price.

I'm sorry but that is nonsense. The main reason why we have DSOs is that they are much more versatile than any analog scope, they can capture, store and process waveforms in a way analog scopes just can't, and can handle bandwidths in excess of 50GHz which would be more than a huge challenge do to with an analog scope (or even with a scan converter tube scope).

Quote
A DSO is much more cheap to make with higher profits. If you make a 100, 200 and 300 MHz DSO you make one model and the software makes 3 out of them. You make a huge profit on the lower models.

Really? Huge profits when selling a 70MHz scope which contains a much more expensive 300MHz frontend?

The reality is that especially low end scopes are a mixed calculation business. Manufacturers save some costs by having to design and manufacture one frontend for three or four models, but on the other side this makes the low bandwidth models more expensive. And especially for the low end scopes manufacturers have to sell a lot of them to turn in any good (not huge) profit. All the big names (Agilent, LeCroy, Tek, R&S) make much larger profits with their midrange and highend gear, and this stuff also operates in areas which are far outside the capabilities of any analog scope anyways.

Quote
If you made three Analog scopes you needed three different CRTs

No, you don't. CRTs in general are not limited in the input signal frequency they can display (the only real limit is the electron acceleration speed which depending on the scope is usually somewhere in the region of 1/3rd of the speed of light in a vacuum, which however is completely unrelated to a scope's analog bandwidth). The deflection circuitry however sets some limits, as does the input frontend. But especially the latter is true for DSOs as well.

Quote
and these become very expensive if frequency increases.

Again, no. What becomes very expensive with frequency is the front end, and in a much smaller extend this might also true for the deflection circuitry, but that's about it.

I guess you're a bit stuck in the 1980's.

If manufactured in the same numbers, there's no reason why say a 100MHz 2ch analog scope could be much cheaper than a 100MHz 2Ch DSO. Until not too long ago Atten made (or rebadged) some cheap low end analog scopes which as far as I know were horrendous, but they were cheap. But the fact remains that these days CRTs have come out of fashion, and as a matter of fact most engineers prefer a compact modern scope which presents a wealth of information in color instead of having a bulky monochrome analog scope with pittiful storage capabilities and (if you have one of the better/later models) includes some wobbly on-screen display of voltage and time base settings.
« Last Edit: May 14, 2013, 08:08:16 am by Wuerstchenhund »
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Offline PA4TIM

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #36 on: May 14, 2013, 08:20:16 am »
Wuersctenhund, i disagree on every aspect, do you even know how an analog scope works, or have you ever repaired one or worked with one ? Do you know the difference between analog and digital sample scopes and that real time on a DSO is far from real time. And the waveform you see is only an aproximation of the true signal looked at for less then 1% of the measurement time ?

There is a book about scopes written by a German scope designer who worked for Tek and Hameg. The reprint is written in 2006 if I remember well. He is not a DSO fan but he knows where he is talking about. It is downloadable, the link is somewhere here on the forum. Read that and we talk again.

( by the way 40 GHz can be done analog too, you forget that are sample scopes, the fastest analog scope was 1 GHz, there is not a single DSO that comes close to that, they are all sample scopes.
Besides that, storage scopes are around for decades.)

About that Tek 2445:
Expensive without a probe. I never look on ebay but I just did, i did know people like to gamble and become ebay addicted. This must be true if I look at the prices. Bizar, a 453 for over 400 dollar, a Tek HV probe for a price that was about 10X what I payed for one of mine ( And I have two of those and thought I had payed a lot because they were in very nice shape, allmost unused and complete)
And the prices for 465 ( depends on the country, Israel seems to be more in the Dutch price range, England is not go bad too, found several 465 under 100 dollar)

You are from France ? Look in Germany or Holland if you do not collect it yourself but have it shipped. I do not know price levels in France.
Best look local on local sites. My 453 and 547 I got for free, two 545A, a 546, and two 535A too, my 7704 and 7603 together bought for 125 euro including some plugins, my Philips PM3410 was for Free, the Fairchild 777 too. A Tek 465 was free, a HP1740 for 100 euro including original probes ect. A 75 MHz Philips for free. Some 50's scopes for free. Not all of them I kept, many I have given away again. At this moment I only have something like 15 scopes. But I regular use the 7704, 7603, Philips 3410, 453 and 547 besides my Hameg DSO.

http://www.ebay.co.uk/itm/Tektronix-434-Storage-Oscilloscope-with-probe-dual-two-channel-/190838749146?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item2c6ee037da

Look for something like this and save money
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Offline luca1000

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #37 on: May 14, 2013, 08:29:28 am »
I live in Italy, so here are a bit expensive I searching in Europe.

Do you know some site (shop) when I can buy some tek in good conditions (and full tested) ?

If possible some shop where you have a direct exprerience or you trust ....




 

Offline rf-loop

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #38 on: May 14, 2013, 08:49:59 am »
I think we speak too generally and this is too aproximative.

For opinion is better a real comparative with a specific model A and B.


Comparation (1)

New Owon SDS7102 (350 Euro)  VS Used good state Tektronix 2465 (250 Euro). Only performance is prioritare for me, not functions or features.

What is the best ??

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

Comparation (2)

New Rigol DS2072  (700 Euro)  VS Used good state Tektronix 2465 (250 Euro). Only performance is prioritare for me, not functions or features.

What is the best ??

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

Comparation (3)

New Tektronix TDS2012C  (1100 Euro)  VS Used good state Tektronix 2465 (250 Euro). Only performance is prioritare for me, not functions or features.

What is the best ??

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

I will use only few hours / years (I' am a hobbist my real work is software developer).

So the probability to break are not very high on my case.

This comparing is nearly fun.
But also there you compare Rolls-Royce to cheap Nissan.

But which one is better in use. It depends 100% and exatly what you do and what is your need.
If you need 400MHz oscilloscope for continuous or repeating waveforms (exept slow speed can also be not repetitive)  this old 2465 beats these others just 10-0

If you need capture  20ns pulse what randomly appear some times per second or minute..  nearly every cheapest digital scope beat this 2465 like 10-0. These can capture it and you see this pulse... and with 2465 you do not see anything(1) what ever you do...even if you work in "dark room"
(1) exept  if you have set trigger right, it blinks every time this pulse appear.

For more complicated things situation and comparing go more and more complex.

It NEED know what is use and what want see and what not and it need personally think.



If you have posibility to go some place where you can use old (good) analog oscilloscope and today cheap digital oscilloscope please go and look with person who can also use these equipments. After then you know what you need. This is nearly only way.



Or, buy this 250eur 2465 and use it and then if you meet situation later that something you really can not do with it, then go and look this day digital scopes.  But how 2465 price can be 250 if it really is good? (or what it means this "good", is it fully functioning and it can also proof and is it also good condition if look real accuracy.
If someone have disturbed internal adjustments (or loose calibration) it need knowledge, equipments and work for do full internal adjustments/clibration procedure  as service manual read and it is not 5 minute bisquit.  And if it have timer/counter option (really nice option)  it need more accurate equipments for this work. Also if I remember right, it need also external  and good oscilloscope etc)

With today cheap digital scopes you do not walk to this situation never.

Personally in many kind of mixed repair/service/adjust many test equipments I want use good analog oscilloscope. This is for me, not for recommend to others. 

With cheap or middle level digital... it can barely but too much  aliazing and other troubles.. and also analog scope is much more fast to use than digital where you need go to this and that menu etc.. or just try look AM modulation with low end digital...  and if you push autosetup many times this procedure do not understand right what is signal and you find you are looking alias.  With unknown signals... with analog scope you see immediately some truth what is there but of course it need exercise and experiment. 

But if you know any single thing now what you need and what this 2465 can not do at all... then stay away from this well made professional equipment. If you need example just stop scope and look...or capture single shot one fast event and then look it. With 2465 you can not.
(ok, old times we use oscilloscope camera what get trigger from oscilloscope...   but also this is difficult becouse in one shot normal crt phosphor "writing speed" is not enough for really fast signal. But also, in old times, there was not so much these signals)

If you think you work with "audio" and it is like analog scope may be ok... why not buy more simple but good Tektronix analog oscilloscope. There are many good models. But stay away these what are made for cheap markets. There is example some 2000 series Tek analogs what can classify just as junk. (designed and made as disposable billowing - but I do not want name these models - it is better to find this information from some other source)

Also some "manyname" entry and mid level old analog oscilloscopes....Ph.... Ke..... Tr..... Hi.... Go.... and dozen of other names  many of these are made just as old cheapest entertainment gears...nice looking and nightmare inside...  after years all switches may have bad contacts and most terrible are some rotary swithes and some multicontact push switches exept some what are really desgned for reliability, potentiometers... and so on.  Many times CRT in these scopes are just cheap crap if compare to best Tek tubes.

For 24xx scopes. Look carefully input attenuators works perfect with all settings and repeatedly without any signs of wear or damage. If change voltage band you must not see any kind of "scratch" in signal or any kind momentarily unreliable level.   (also 50ohm)

It is also different situation if scope have 60000 power on hours or if it have 1000hours. But yhen, there is so different hours...just as in car..there is just so different kilometers.

 
First there is lack in CRT dynamic.  Adjust trace to left border using example 10us or something... turn fastest speed.. look  trace...it may disappear from 1-3 divs area from left. Turn more brightness. How near left side you can see it without very bad focus.

But what means perfomance, functions, features.
Perfomance is important...  what you need perfomance if you can not use it for your needs.

Is it nice to keep performance and quality on the exhibition shelf  becouse no use.

(I have here several  Tek24xx models/versions here in good/extremely good working condition and also I active use some  unit what I have reserved for my own use. And I know, as far as work, I will never end using analog scope. If I go to situatoin that some tell me I can keep just one... just only one.. yiu name it. It is easy peace of cake. I keep my 2465B and all dgitall cheaper and more expensive scopes can go) 2465 keep just becouse Tek7000's I have  and plugins is too heavy and big lot.)

eur 250 for real good condition 2465 is nearly like get free.
If practice and theory is not equal it tells that used application of theory  is wrong or the theory itself is wrong.
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Offline Wuerstchenhund

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #39 on: May 14, 2013, 09:28:37 am »
Wuersctenhund, i disagree on every aspect, do you even know how an analog scope works, or have you ever repaired one or worked with one ?

Yes, thanks, in the last two+ decades I have worked with quite a lot analog scopes (mostly Tek 7000, but also several other models from Tek, HP, Hameg and Philips; I actually also designed/built one for a work project many moons ago). That's btw one reason why I know that CRTs have nothing to do with an analog scope's bandwith, which are very basic technical facts.

Quote
Do you know the difference between analog and digital sample scopes and that real time on a DSO is far from real time.

Yes, so what? Even an analog scope is not really 'real time', it just has a lower latency than a DSO.

Quote
And the waveform you see is only an aproximation of the true signal looked at for less then 1% of the measurement time ?

Aside from the fact that the percentage is dependent on various factors and not a fixed number, again so what? Unless you have a really crap scope or use the wrong scope for the job then the signal approximation is more than good enough. And do you really want to suggest that the various components in your analog scope have no effect on the signal that is displayed on the screen? Well, they have. You may not notice it as on good scopes the effect is very small (and on an analoge scope you only get what you see on the screen, unlike with DSOs), but it's there. There simply is no scope which offers 100% fidelity.

Quote
by the way 40 GHz can be done analog too, you forget that are sample scopes, the fastest analog scope was 1 GHz, there is not a single DSO that comes close to that, they are all sample scopes.

Again, you may want to have a look at the calender, because its 2013 not 1993, and nowadays scopes do 50+Ghz real-time. For example, LeCroys LabMaster 6Zi has 65GHz analog bandwidth and samples at 160GSa/s. real time, not (time equivalent) sampling. They do have sampling scopes, too (WaveExpert, up to 100GHz). LeCroy is top at the moment but Agilent and Tek have similar offerings, albeit with a bit lower bandwidth and sampling rate.

Now please show me which analog scope can do better, or at least the same? Exactly, none. 1GHz bandwidth is nothing for digital scopes these days (or even 10 years ago), but it's already a challenge for analog scopes.

Quote
Besides that, storage scopes are around for decades.

As are DSOs (which don't suffer from all the disadvantages of analoge storage scopes). And your point is?
« Last Edit: May 16, 2013, 08:02:56 am by Wuerstchenhund »
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Offline rf-loop

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #40 on: May 14, 2013, 10:22:00 am »
That's btw one reason why I know that CRTs have nothing to do with an analog scope's bandwith, which are very basic technical facts.


Really?   
In practice I disagree this claim.


Perhaps you can go to Beaverton and tell to Tektronix oldmans that all they have been wrong.


But of course this whole case is cpomplex and there is many difficult things including component sizes etc etc.  But also, CRT itself. 1GHz beam moving vertically is not easy piece of cake. It start come bottleneck.  Of course we can rise kilovolts and make long small angle tubes but... 



(But af course together with driving vertical plates)
If practice and theory is not equal it tells that used application of theory  is wrong or the theory itself is wrong.
It is much easier to think an apple fall to the ground than to think that the earth and the apple will begin to move toward each other and collide.
 

Online BravoV

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #41 on: May 14, 2013, 10:32:43 am »
That's btw one reason why I know that CRTs have nothing to do with an analog scope's bandwith, which are very basic technical facts.


Really?   
In practice I disagree this claim.


Perhaps you can go to Beaverton and tell to Tektronix oldmans that all they have been wrong.


But of course this whole case is cpomplex and there is many difficult things including component sizes etc etc.  But also, CRT itself. 1GHz beam moving vertically is not easy piece of cake. It start come bottleneck.  Of course we can rise kilovolts and make long small angle tubes but... 



(But af course together with driving vertical plates)

I have to agree with rf-loop on this one, even though I'm just an enthusiast and my knowledge & skill are nothing and not worthy compared to you guys that are far more experienced.

Of course this is not an ordinary crt.

Read this here -> http://www.oregonlive.com/silicon-forest/index.ssf/2011/09/a_tektronix_oscilloscope_that.html

Offline Wuerstchenhund

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #42 on: May 14, 2013, 10:45:37 am »
That's btw one reason why I know that CRTs have nothing to do with an analog scope's bandwith, which are very basic technical facts.

Really?   

Yes, really. The CRT itself (asuming a modern variant and not one of Braun's original experients of course) is generally primarily limited in the speed of how fast it can move the electron beam by the mass of electrons (which is very low) and the acceleration (which is very high, roughly in the region of 1/3rd of c).

On very old electrostatic deflection tubes the area of the platters also played a part (as it does take longer to charge them up) because the capabilities of the deflection circuitry and the manufacturing of the yoke was much more limited than nowadays. However this is not an issue for modern CRTs (i.e. made after say 1990), which is what the initial argument was about as to why we don't have many new analog scopes any more (stating that tubes for higher bandwidth analog scopes would be too expensive).

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In practice I disagree this claim.

You of course are free to disagree with anything you want.

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Perhaps you can go to Beaverton and tell to Tektronix oldmans that all they have been wrong.

Then please show me where these 'Tektronix oldmans' state that nowadays (i.e. after the 1950's) the bandwidth of analog scopes is limited by the CRT.

But maybe these 'Tektronix oldmans' were well aware that the real limit is not the CRT but actually the deflection circuitry, which is very much limited to what frequencies can be reached. And the problem with deflection is the main reason why we haven't seen many 1+GHz analog scopes (aside from the fact that these days not many would buy a new 1+Ghz analog scope).
« Last Edit: May 14, 2013, 12:50:14 pm by Wuerstchenhund »
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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #43 on: May 14, 2013, 10:53:40 am »

I have to agree with rf-loop on this one, even though I'm just an enthusiast and my knowledge & skill are nothing and not worthy compared to you guys that are far more experienced.

Of course this is not an ordinary crt.

Read this here -> http://www.oregonlive.com/silicon-forest/index.ssf/2011/09/a_tektronix_oscilloscope_that.html

I did read it, but maybe you can point me to where in the text is says that on analog scopes the input bandwidth is dependent on the cathode ray tube (CRT)? Because the article I found at your link only talks (very simplistic) about 'superluminal velocity' and how a similar effect is visible on the Tek 7104.
« Last Edit: May 14, 2013, 12:48:51 pm by Wuerstchenhund »
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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #44 on: May 14, 2013, 01:53:15 pm »
What you think if I try to search only the 2445 (150 Mhz) for 250 Euro ?

This  because the more expensive 2455 / 2465 are 300/400 Mhz and need expensive probe and there are less chance to get in good condition for this price.

What you think ?

I don't want consider a 22xx series or less becouse they don't have a on screen informations (frequency , time base , voltage , etc...).
 

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #45 on: May 14, 2013, 03:04:49 pm »
I have changed idea I like to consider for now only these models (for max 250 Euro) in good state:

Tektronix   2445   150MHz 4CH Oscilloscope $3,590 (original price)      Informations On screen

Tektronix   2246   100MHz 4CH Oscilloscope $2,595 (original price)      Informations On screen

Tektronix   2236   100MHz 2CH Oscilloscope $2,995 (original price)      DMM digital inside
 

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #46 on: May 14, 2013, 06:56:41 pm »
What you think if I try to search only the 2445 (150 Mhz) for 250 Euro ?

This  because the more expensive 2455 / 2465 are 300/400 Mhz and need expensive probe and there are less chance to get in good condition for this price.

What you think ?

I don't want consider a 22xx series or less becouse they don't have a on screen informations (frequency , time base , voltage , etc...).
I used to have a Tektronix 2230 and it has on-screen readouts for sure. You can disable these ofcourse. Still, do yourself a big favour and get a DSO. People who say a DSO doesn't display signals completely have no grasp of sampling theory. Fortunately the designers of a DSO do. I used to think a DSO couldn't match an analog scope but I was wrong. My previous two scopes where digital / analog but in the end I never used the analog mode because it is clumsy compared to the DSO mode. Nowadays I use a DSO exclusively for everything (audio, digital, high voltage, etc). Thanks to features like averaging, high resolution you can also clean-up a noisy signal.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #47 on: May 14, 2013, 07:44:29 pm »
So I guess the Rigol DS1102E (~400USD) has fallen out of favor for someone who must must must stick to less than $500 or so?
 
I nearly picked one up myself a few months back before losing resolve on my budget.
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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #48 on: May 14, 2013, 07:47:48 pm »
This book is fun to read (and useful).
Specially whole chapter 6.
This is last updated 2006 so it is old but still so much true.

http://w140.com/Handbook_of_Oscilloscope_Technology.pdf

"Dr.-Ing. Artur Seibt
Handbook of
Oscilloscope Technology
Circuitry – Accessories - Measurement – Selection Criteria - Service
2nd extended and updated edition 2006"

418 pages.
Keep fun.

but still this book keeps inside lot of truth and today oscilloscope manufacturers do not like it.
Becouse making digital scope is ...yes - in many things useful for users but perhaps it is not whole truth  and  also in other hand, cheap to make.  Mirror have two sides..


But nice question:
What is yours DSO bandwidth calculated by 1/2 x sampling speed if you turn it to 50ms/div.

Tektronix 2465B have 400MHz simultaneously for 4 channel using 50ms/div horizontal speed.
Owon SDS7102 have 2.5MHz.  for two channel
Rigol DS1000E have  ~437kHz for two channel
Hantek DSO500B HW1005 have 250kHz for two channel (40ms/div).
Siglent SDS1000xxL have 250kHz only for two channel.
How much Agilent 9000 infiniium have, I do not know.

Now in cheap DSO if there is any frequency componet over this bandwidth it produce total false informations. Of course if you know your signal... but if you know your signal why you need oscilloscope. Only for fun playing?

With DSO you have 1Gsa/s but only in some cases.  But analog old work horse is always 400MHz.  And even with 800MHz included to signal under test it do not produce any alias (btw, how you know really that alias is alias or if your signal have it really what you see on the screen?
Sinewaves are still easy but complex signals may have lot of freq components and when you look it with DSO you really do not know exactly sure anything if there is aliasing.

In true it is perhaps example 50sa/s to 1GSa/s dependent your horizontal speed.

THis is why I use in service and repair work still analog oscilloscopes for many times totally unknown signals - it need take to count that signal is undefined and I need solve what is there. This can not do easy with cheap DSO but it can do very reliable using analog oscilloscope specially if time is also limiting factor and then also  it need look UI. Where is better UI than in well designed analog professional scope if agen think useability in situations where also thíngs need do fast. Do it with finding and adjusting things in this and that 1st and 2nd  and 3rd level menu system.  I do not need find anything but push or turn this knob on front panel and this I can do even with eyes closed. Analog for avoid falses and for saving time. Time is expensive. 

but of course, needs are so different... also I use DSO's
Then if look example hobby things where is limited money, and one equipment need be as multitool for somehow for "everything". In many cases digital cheap oscilloscope give lot of with this money. But if people know what he need and if this is better for analog than cheap digital... why need buy digital - just becouse they are now everyboy fashion?
I know photographer who have take prhaps one of most nice art photographs.. what he have usede.. old 1930 analog camera and no one can beat him even today with most expensive and feature rich digital. Becouse people do it... not this camera. our grandfathers and fathers have done with analog oscilloscopes so miracle studies that even with good digital scope most peoples can not. But vthere was combination, not only scope. There was human brains and scope together. Today all need be only easy and more easy and fun. 

If someone tell that analog scope is useless and always only right scope is digital... welcome and show it in real life. I give some work for you and start second watching. Of course there is also lot of of (perhaps more) opposite things  -- things what can not do with analog scope or they are difficult and they are easy piece of cake with even cheapest digital.  Thjis is why I have also digital.  Together they are like combiscope.
« Last Edit: May 14, 2013, 09:06:07 pm by rf-loop »
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Offline PA4TIM

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #49 on: May 14, 2013, 08:58:11 pm »

There is a book about scopes written by a German scope designer who worked for Tek and Hameg. The reprint is written in 2006 if I remember well. He is not a DSO fan but he knows where he is talking about. It is downloadable, the link is somewhere here on the forum. Read that and we talk again.

Thanks RF-Loop, that was the link I was looking for, great book. Real eye opener.  I agree with your comments in this discussion, but I'm afraid it is to late. The DSO is allready declared holy by most users, the power of fancy colors , lots of gadgets and for most the no-brain button (auto)  >:D

Just to show the difference between a good and a less good scope. The same measurement on three scopes. It is a reverse recovery time measurement of a 1n4148.

A Rigol DS1102e, dreadfull child like point to point drawing and Trr > 10ns and a 13.4mV dip. (100 MHz scope)

Hameg HMO-3522, around 2 ns and 50 mV (350 MHz scope)

Tek 7603A coupled to a 132 carrying a 1S1 1GHz sample plugin. readout has no function here. (this are two pictures over each other, the 1S1 is single channel)
« Last Edit: May 14, 2013, 09:02:44 pm by PA4TIM »
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