Author Topic: Owon SDS7102 or Tektronix TBS1062 or TDS1002  (Read 21927 times)

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Offline luca1000

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Owon SDS7102 or Tektronix TBS1062 or TDS1002
« on: May 11, 2013, 07:19:18 am »
Hi,

I need your opinion about Owon SDS7102 (420$) in comparation with Tektronix TBS1062 or TDS1002 (870$).

The price of tektronix is double but the tech and features seem the some.

In particular I like to known if TBS1062 or TDS1002 offer better performance in terms of noise, accuracy, trigger, precision.

I'am not interested about the functions that they offer that are more then sufficuent for my porpues.

Some people affirm that Owon is chinese machine and never can compare with Tektronix (this indipendently by the model).

I like to use it for hobby, and at beginning my first idea was consider some Old tektronix like 2465, 2445 , but need too many space that I don't have, so only digital oscilloscope I can consider.

If someone have some experience with this model 'SDS7102' and tektronix please share your opinion.

« Last Edit: May 11, 2013, 07:22:42 am by luca1000 »
 

Offline EEVblog

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #1 on: May 11, 2013, 08:18:59 am »
I need your opinion about Owon SDS7102 (420$) in comparation with Tektronix TBS1062 or TDS1002 (870$).
The price of tektronix is double but the tech and features seem the some.

Err, not even close!
The Tek has a pathetic 2.5K sample memory. The Owon has 4000 times more, at 10M.

Quote
I like to use it for hobby, and at beginning my first idea was consider some Old tektronix like 2465, 2445 , but need too many space that I don't have, so only digital oscilloscope I can consider.
If someone have some experience with this model 'SDS7102' and tektronix please share your opinion.

The Owon is a cheap unit for sure, but the Tek, whilst a top quality unit, is just a such a pathetic joke in todays market, you'd be foolish to buy it. The Tek is based on a 15 year old design.
If they are your only two choices, buy the Owon.
 

Offline luca1000

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #2 on: May 11, 2013, 08:28:09 am »
Many thanks for your response !!!

For your opinion there is the possibility to see some video (youtube) comparation about OWON SDS7102 with some Tektronix models (Analog or new Digital) ?

Apart this, I was try to see the best price / quality for 400-460$ and the OWON SDS7102 seem the best in terms of noise, precision and in general performance. Do you agree ?
 

Offline Wuerstchenhund

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #3 on: May 11, 2013, 08:34:22 am »
I fully agree with Dave. Tektronix was a good choice and a save buy in the past but nowadays their oscilloscope offerings are behind other manufacturers. They still produce top quality equipment but you dearly pay for that.

Is your choice only limited to these three models? If not, I'd also have a look at the Siglent SDS1102CFL, or if you're prepared to pay a bit more the Rigol DS2102.
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Offline luca1000

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #4 on: May 11, 2013, 08:43:34 am »
I understand that here like other situation with Tektronix you pay the "brand" and you can get similar performance (not identical) with chinese brands with less cost.

Siglent SDS1102CFL and Rigol DS2102 are more then double price (>1000$) , the OWON SDS7102 price is < 500$.

My range is <500$.
« Last Edit: May 11, 2013, 08:46:12 am by luca1000 »
 

Offline rf-loop

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #5 on: May 11, 2013, 09:33:27 am »
There is so many different needs.

About memory. I want fast and deep memory...

.... but it is not whole truth always.


 Example with one my scope I can adjust sample memory down to 40 sample (and less) but only in segment capture mode!
Some times I hope that scope manufacturers add feature where user can adjust sampling buffer lenght for reduce this part sampling  what is not visible on realtime  screen but still captured and just go to waste station. (example if needed for eyes 50 samples  and to waste station all 9950 samples (10k) after every sampling period)

IF some people use digital oscilloscope so that he just look live realtime screen like analog oscilloscope.  Many times peoples do this.

Example:
1GSa/s and horizontal time 2ns/div.
How many sample points there is visible on the displayed area.

If display horizontal area is example 15div. There is 30 real samples on the visible area!
In this case you need 30 point memory IF you are just looking this running scope live display (just as analog scope, but still you have many digital scope positive and some negative features)!
Not need 500, 1k or 2,5k or even more.

It need carefully think what is real need just in my use. If people do not know what he is doing and what he need, thenh he need universal machine where is all just for "if need" and if in this case it also need be cheap.....it is difficult equation. 
Professional peoples who make money with tools, have many times possible to buy equipment just for specified needs, so example for some use just this Tek 2.5k is perhaps ok. For some other need they perhaps buy Hewlett-Packard (yes I like use this name becouse Agilent have destroyed lot of things what HP was) 9000 infiniium or some R&S RTO.  Just as right equipment for right use. Hobbyist position is different in most cases.

Why I can not select this 30 point memory depth. Why it still need capture 2500 samples (2.5k or in some  example 20k samples or what ever this oscilloscope model have) if I' just looking screen and these 30 sample points.

If there is now this 2500sample points it means that there is 1250 horizontal div captured but I look in live on the screen area only 15 div. When I'm adjusting some thing in example service or repair situation etc.

If there is 10ksample buffer There is 5000 div long capture (10000 samples) but still im looking only 30 samples.  In this case, there need 30 samples memory, not 1k, 2.5k or 1M.

If I can adjust needes memory and get more waveforms update rate......  it is nice.

Of course this was trivial example but many times this is also easy to forget that in some cases but many times you just use 20-50 sample points.

Of course for more and more slower horizontal speeds need more and more memory for keep samplerate high.  Cheap entry level Owon can keep 1GSa/s down to 500us/div with 10Mpoints memory. But with this speed example 1k points memory  can use only maximum 100ksample/s.

For real time watch running oscilloscope display with fastest timebase there is needes only some tens of samplepoints memory. If this is main use, no need care about memory depth. All these oscilloscopes have much more than enouggh. Even this Tektronix 2.5ksample.

In laboratories some times ago they did lot of high-end electronic works with just 500 points sampling buffers. And all these can do also today with same amount of memory. If do these same things. Do you know what kind of camera peoples have used in history for perhaps most good photographs ever made. This is partially not in equipments, it is in user and his skills also.

This comment is ONLY for thinking, is it all times important to think sampling memory depth. Perhaps some times need think how to reduce sampling memory example foir more fast capturing.
(yes "perhaps" some clever oscilloscopes use automatically some these kind of "intelligent" things for example maximize update rate using some kind "clever" memory depth adjustment - (edit/add: example HP have done this kind of things longlong  time ago. But sometimes want full manual control... I'm (sometimes) more clever than machine for think what I need....))

It depends what you are doing and also how.  Also it is true that in many cases, experienced peoples can do miracles with tiny simple equipments and some peoples can not even if they have most high level equipments but they can tell to friends that I have more big than you.
« Last Edit: May 11, 2013, 11:26:13 am by rf-loop »
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Offline luca1000

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #6 on: May 11, 2013, 10:05:16 am »
Thank you for your complete and detailed comment.

I like an oscilloscope with good performance and with these features:

1) Low noise possible. This is the primary objective. (Probably I need to purchase ather probe becouse the standard probe seem not good).
2) Good precision (in vertical and horizontal).
3) Good trigger.
4) Good quality of imaging (interpolation and anti-aliasing)
5) Good sensibility (minimum 2mV)

Factors that don' t are primary for me:

1) Functions that offers.
2) Size.
3) External trigger
4) Real time use.
5) Higher frequency (40mhz is sufficient for me).
6) More then 2 channel.
7) other characteristc that don't have nothing to do with general performance.


For <500$ the Owon SDS7102 is best choice ?
« Last Edit: May 11, 2013, 10:29:46 am by luca1000 »
 

Offline marmad

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #7 on: May 11, 2013, 10:38:27 am »
Why I can not select this 30 point memory depth. Why it still need capture 2500 samples (2.5k or in some  example 20k samples or what ever this oscilloscope model have) if I' just looking screen and these 30 sample points.

If there is now this 2500sample points it means that there is 1250 horizontal div captured but I look in live on the screen area only 15 div. When I'm adjusting some thing in example service or repair situation etc.

If there is 10ksample buffer There is 5000 div long capture (10000 samples) but still im looking only 30 samples.  In this case, there need 30 samples memory, not 1k, 2.5k or 1M.

If I can adjust needes memory and get more waveforms update rate......  it is nice.

Of course this was trivial example but many times this is also easy to forget that in some cases but many times you just use 20-50 sample points.

Just as an aside (and off-topic) comment: this is exactly what Rigol has (cleverly) implemented in their UltraVision scopes; when you select the Auto setting for sample length, it uses only the number of samples needed for the current time base setting (e.g. at 2GSa/s, it uses 56/140/280/560 bytes respectively for 2ns/5ns/10ns/20ns settings).
 

Offline EEVblog

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #8 on: May 11, 2013, 12:19:45 pm »
I understand that here like other situation with Tektronix you pay the "brand" and you can get similar performance (not identical) with chinese brands with less cost.

You seem to be overrating what the Tek is capable of.
The TEK has the worst memory depth on the market, borderline unless by modern standards. It is a 15 year old model (I'm not kidding).
Every low cost scope on the market beats the Tek hands down on memory depth. The Tek TBS sets no benchmark in the market at all, it is a joke.
 

Offline EEVblog

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #9 on: May 11, 2013, 12:21:03 pm »
1) Low noise possible. This is the primary objective. (Probably I need to purchase ather probe becouse the standard probe seem not good).

Then the Rigol DS2000 wins hands down with low noise 500uV/DIV front end.

 

Offline luca1000

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #10 on: May 11, 2013, 12:31:42 pm »
Quote
Then the Rigol DS2000 wins hands down with low noise 500uV/DIV front end.

Yes the Rigol DS2000 is better then OWON SDS7102 but the cost is double:

Rigol DS2000: 800-900$
OWON SDS7102 420-460$

I searching for some scope from 400-500$.
 

Offline EEVblog

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #11 on: May 11, 2013, 12:34:02 pm »
Quote
Then the Rigol DS2000 wins hands down with low noise 500uV/DIV front end.

Yes the Rigol DS2000 is better then OWON SDS7102 but the cost is double:
I searching for some scope from 400-500$.

You can't get the best of both worlds.
If low noise performance is important to you, you have to pay for it.
 

Offline Wuerstchenhund

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #12 on: May 11, 2013, 12:37:33 pm »
I understand that here like other situation with Tektronix you pay the "brand" and you can get similar performance (not identical) with chinese brands with less cost.

Nope. Years ago, Tektronix was one of the leaders in scopes, offering top-notch technology and features. This is also the reason why Tek scopes are as common as Athlete's Foot.

Nowadays, Tek is merely a ghost of the past. They have lost to Agilent and especially LeCroy in the midrange/highend segment, and their entry level scopes can't even compete with a less than 500$ China scope.

As Dave says, you would be mad if you bought a Tektronix scope today.

Quote
Siglent SDS1102CFL and Rigol DS2102 are more then double price (>1000$) , the OWON SDS7102 price is < 500$.

My range is <500$.

Then look at the Siglent SDS1102CML. I got a new SDS1102CNL (same as CNL but with smaller memory) today and for that price it's really good.
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Offline luca1000

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #13 on: May 11, 2013, 12:47:15 pm »
Quote
You can't get the best of both worlds.
If low noise performance is important to you, you have to pay for it.

Yes, you have right.

I suppose that part of noise depend by the probe that generally are very low cost in these objects.

I see some example is some forums.

Is true for your opinion ?
 

Offline marmad

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #14 on: May 11, 2013, 12:58:13 pm »
Then look at the Siglent SDS1102CML. I got a new SDS1102CNL (same as CNL but with smaller memory) today and for that price it's really good.

Wuerstchenhund - you bought a Chinese DSO? Say it ain't so!  ;)
 

Offline PA4TIM

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #15 on: May 12, 2013, 11:31:33 pm »


I like an oscilloscope with good performance and with these features:

1) Low noise possible. This is the primary objective. (Probably I need to purchase ather probe becouse the standard probe seem not good).
2) Good precision (in vertical and horizontal).
3) Good trigger.
4) Good quality of imaging (interpolation and anti-aliasing)
5) Good sensibility (minimum 2mV)

For <500$ the Owon SDS7102 is best choice ?

1) not the most low noise possible, not even close
2) forget it, Owon only cares about one thing, low pricing
3) most DSO' s are not bad at that
4) buy a agilent, Hameg or the expensive Rigol line
5) Hameg rules there

But for this budget you have not much choise. All these topics are alike, how to get the less worst scope for as little money as possible. Good scopes cost money. How good you need is up to you. But at 400 dollar it does not matter.

I do not agree totally with Dave about the older Tek DSO's. I had a " pathetic"  60 MHz TDS210 for a while here to play with and it was for my use (so for what was important for me) a better scope as my former Rigol DS1102E (still find that my biggest waist of money (900 euro back then for the most crappy piece of shit I ever bought, and I really wished I had not read all those good critics about it back then, so that is why I am maybe a bit over-negative, but it was my hard earned money down the drain), but if you are into digital stuff the Rigol probably is better.

and all these Chinese brands are rather close and only interested in lowest price. An Owon and two extra real good probes cost probably more as the Rigol and Rigol probes (RP2200) are also rather bad (response is much worse as a 20 year old 100 MHz Tek and mechanical they are a disaster (I slaughtered one that died after a few months)

just my two cents. (I have now a 350 MHz Hameg DSO (still love it as much as the first day)  and a dozen Analog scopes, most from Tek)
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Offline Hydrawerk

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #17 on: May 12, 2013, 11:53:18 pm »
https://www.eevblog.com/forum/testgear/new-tek-tbs1000-scopes/
 :-DD ^-^
Thank you for your well reasoned counter argument. You raise many new points that were not already mentioned in this thread, and more specifically address all of the points mentioned by luca1000 and PA4TIM.
 

Offline luca1000

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #18 on: May 13, 2013, 11:00:32 am »
The Tektronix old models are easy to find used on ebay.

For example here there is an expired offer of only 230 Euro for a TDS 220:

http://www.ebay.co.uk/itm/Oscilloscope-Tektronix-TDS-220-with-2x10-probes-P6112-/380638212548?_trksid=p2047675.l2557&ssPageName=STRK%3AMEWAX%3AIT&nma=true&si=4aWPYKpMfEpe%252Fyh7%252FslQvf6FAKo%253D&orig_cvip=true&rt=nc

if for example I find some used  TDS1002 for 300-350 Euro (some price of new Owon SDS7102) what is the best ?

the TDS1002 , TDS-220 and similar have small memory but don't have any defected like "short ground issue" (Owon SDS7102) that is a not small problem (the noise is important for me).

What you think about ??
« Last Edit: May 13, 2013, 11:03:25 am by luca1000 »
 

Offline PA4TIM

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #19 on: May 13, 2013, 11:12:03 am »
i do not see a relation to my comments. I did not say that Tek model is good. I agree with Dave and the rest on that. But not every olde digital Tek is bad and i wanted to make a point that what is important for one user not has to be important for an other. If you repair tube amps or high power RF transmitters your demands are different then when you measure on designs that involve signals in the uV area or very fast signals. And for digital stuff your demands are different too.

i would not feel save to measure the ripple on a 600VDC powerrail of my guitar amp with that owen.That Tek may be bad but if Tek or Agilent writes the probe or scope is rated X Volts I trust those  specs. ( but use my 547 for that)
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Offline luca1000

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #20 on: May 13, 2013, 11:22:09 am »
Probably the best solution for hobby audio porpues (I'am an audiophile) is buy some used tek 2465 / 2455 etc... but I don't have space and object like this can easy break.

So digital is the only possible choice.
 

Offline PA4TIM

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #21 on: May 13, 2013, 12:16:35 pm »
space is a different story but I have perfect working analog scopes that are over 50 years old. My 1960's Tek 453 or Tek 547 probably still work long after the now new bought Owons ect stopped working (I guess they will last 5 to 10 years like most consumer stuff) and if an analog scope breaks there is a very good change it can be repaired.

look at the max voltages of the Owon ( i'm to lazy ;-) ) and then when used with a 1X probe. because there will come a time you have it at 1X when you measure high voltage. murphy is allways around.
then look at the voltages you measure. That can be more important as noise
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Offline luca1000

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #22 on: May 13, 2013, 03:07:28 pm »
I have changed idea I will buy some used tek 2465 / 2455 etc , that is best solution , I will find the space in some way.

So in this mode I can forget all problems and compromises about the performance ...
« Last Edit: May 13, 2013, 03:15:53 pm by luca1000 »
 

Offline PA4TIM

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #23 on: May 13, 2013, 05:36:24 pm »
For audio ? Yep, why not, or a  tek 465, 2445 ect, no need to go over 100 MHz, allmost every decent analog scope will between those models will do. HP made a nice 1740 ( and other models around this one)
If you do tube equipment, or audio with higher voltages, these scopes can tolerate more as a DSO

Test it good before you buy it and buy it including the right probes.  I have had a 2445A and a 465. The 2445 has some nice options and is a 4 channel 150 MHz scope. I payed 150 euro for it over here including good Tek probes but that was cheap. Most times they do around 200 - 250 euro.
A nice 465 (on of the best portable scopes they made according to Jim Williams, 100 MHz)  will be cheaper, 50-150 euro ( is older, but when needed repair is much more simple as a 2445)
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Offline luca1000

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #24 on: May 13, 2013, 06:51:51 pm »
This is the first choice that I was think, but someone tell me

"don't buy a old analogue, a new digital is far better ...." I don't belive it !!!!

Now I have take the decision:

Budget 200-250 Euro (not more) for a old good condition Tek 24xx series, becouse was the best on 1985-1990.

I suppose a old tek 24xx (250 Euro) can be compare to a new rigol ds2072 (700 Euro)

http://www.rigolna.com/products/digital-oscilloscopes/ds2000/ds2072/

Do you agree ?
« Last Edit: May 13, 2013, 06:54:24 pm by luca1000 »
 

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.
 

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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.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

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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www.schneiderelectronicsrepair.nl  repair of test and calibration equipment
https://www.youtube.com/user/pa4tim my youtube channel
 

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.
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.
 

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.
 

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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).

Quote
In practice I disagree this claim.

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

Quote
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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Offline 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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Offline luca1000

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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...).
 

Offline luca1000

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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
 

Online nctnico

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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.
 

Offline Yaksaredabomb

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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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Offline rf-loop

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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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Offline luca1000

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #50 on: May 14, 2013, 09:06:08 pm »
OK, I don't know if this question can be ask or there is no response:

If I compare a Tek 2445 and a Rigol DS2072.

I like to known, if possible,

1) what is the scope with a better dynamic range.
2) what is the scope with lower noise.
3) what is the scope with best channel separation.
4) What is the scope with less jitter.
 

Offline Hydrawerk

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #51 on: May 14, 2013, 09:29:00 pm »
http://www.pa4tim.nl/wp-content/uploads/2010/11/1n4148.png
This doesn't look like a printscreen from a DS1000 scope... What's that??
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Offline jpb

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #52 on: May 14, 2013, 10:12:16 pm »
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 interesting but it is not really fair on modern DSOs. 50ms/div is very slow - implies that you're looking at signals down to about 2Hz (one wavelength in 0.5 secs). Also if you use peak-detect high frequency noise would show up as the sampling rate will be 1GS/s, the points just won't be stored.

If something then looks odd, you'd presumably go to a faster time base and the sampling rate would rise.
 

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #53 on: May 14, 2013, 10:23:58 pm »
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?
Like I said. No grasp of sampling theory. The book you link to are just some random ramblings (*). Tektronix has published some real books on how to design an oscilloscope (and other equipment). You better read that because those where written by people who actually build test equipment!

Anyway, a key feature of a DSO is peak detect or envelope mode which makes the samplerate irrelevant. Peak detect basically does what an analog scope does only much better. Even extremely short pulses which are invisible on an analog scope (with the same bandwidth) are visible on a DSO. If you need to clean up a signal you can change the acquisition mode to sample mode, average or high resolution. Try to do that with an analog scope....

(*) After reading the first line of the book you know the truth is where the money came from:
After ten years from its first edition this handbook needed updating. HAMEG Instruments GmbH, a major manufacturer of both Combiscopes and analog scopes a subsidiary of Rohde & Schwarz, sponsored this second edition.
Just skipping through it I already spotted lots of errors like you'd need the samplerate to be at least 10 times the bandwidth. Utter nonsense and shows the author clearly has no clue about the difference between sampling a signal and displaying a signal.

Another snippet where the author admits he doesn't now what he is writing about:
it is not possible to truly judge DPO’s, this would require an extensive test.
Without scientific evidence any claim is a mere opinion.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Online nctnico

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #54 on: May 14, 2013, 10:25:09 pm »
for most the no-brain button (auto)  >:D
Which is also available on every analog scope made after approx. 1990 as well. Never used it though.
« Last Edit: May 14, 2013, 10:28:05 pm by nctnico »
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Offline PA4TIM

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #55 on: May 14, 2013, 10:44:44 pm »
That was my 900 euro down the drain Rigol DS1102e .But Trr are no easy measurements. For most standard  measurements it was usable.  A year later or so they dropped the price by 40% or so, after everybody started upgrading the 1052

This is a normal measurement.

.

Quote
If I compare a Tek 2445 and a Rigol DS2072.

I like to known, if possible,

1) what is the scope with a better dynamic range.
2) what is the scope with lower noise.
3) what is the scope with best channel separation.
4) What is the scope with less jitter.

1) Do you mean min/max input ?
Tek=  800Vpp AC upto 10 kHz and 400VDC+AC for the whole frequency range (straight at 1 M input)
Rigol: CAT I 300 Vrms, CAT II 100 Vrms

2) do not know but probably the Tek, at least I, never had noise problems with that.

3) 2445 = 100:1   That is 40 dB if I'm right
Rigol = 40 dB too
4) 2445 less then 100 ps at 150 MHz and I read somewhere here +/- 200ps on the Rigol


Quote
Anyway, a key feature of a DSO is peak detect or envelope mode which makes the samplerate irrelevant. Peak detect basically does what an analog scope does only much better. Even extremely short pulses which are invisible on an analog scope (with the same bandwidth) are visible on a DSO. If you need to clean up a signal you can change the acquisition mode to sample mode, average or high resolution. Try to do that with an analog scope....

But that extreme short pulse must  occure  in the extreme short time the scope is realy measuring instead of doing other things. I had a problem with runts while repairing a Fluke 8500. It drove me nuts. Nothing to see on the Rigol. Thenm I took the 7704 and I noticed some flashes now and then. Then using the whole arsenal of tricks the DSO was usefull because now I knew what to look for and after a lot of hassel I could capture it. ( but to be fair, the flashes on 7704 gave me enough info. Repairing a sat tuner I had a nice ripple on my Hameg, so all looked OK, but it was not. I hooked up my 7603 and I noticed a dip flashing buy every now and then. Like once in 10 or 20 seconds. Turned out a cap was shorting for a very short time at that moment. After that I could find it on the Hameg to, but like Bob Pease once said, if I know the signal I do not need a scope.

That guy designed scopes and I know it is hard to believe with a brainwashed digital mind but he is not telling nonsens. Most  good Tek books are even older, the later once from the digital area tell you only what you want to hear....

Are you serious ? Never seen real auto on analog scopes but I have no analog scopes from after 1990. But does that set timebase, trigger and V/div and on a real analog scope. ? I'm curious, never knew this, please name a model.

 Auto as I know on an analog scope is only autotrigger to get a trace. Even my 1966 453 has it. But that is not a bad thing.
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Offline rf-loop

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #56 on: May 15, 2013, 06:51:56 am »
Never seen real auto on analog scopes but I have no analog scopes from after 1990. But does that set timebase, trigger and V/div and on a real analog scope. ? I'm curious, never knew this, please name a model.

Something example like this, Tektronix 2445B, 2455B, 2465B
In manual there is more explanations.

Just push AUTO on scope front panel or button in probe.


« Last Edit: May 15, 2013, 07:03:08 am by rf-loop »
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 PA4TIM

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #57 on: May 15, 2013, 07:51:47 am »
http://www.pa4tim.nl/wp-content/uploads/2010/11/tekgewoon.jpg this was my 2445, that had no auto button (as far as I can see). Never knew the 2445B was besides a bigger bandwidth so much different on other things too. Nice, thanks for the info.
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Offline luca1000

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #58 on: May 15, 2013, 08:26:44 am »
This 2445 or similar have a particular very good fashion !!

Seem the Top on the Top and this can be pay only some few euros !!!!

I don't understand WHY the people (and I include me in this list) was think to choose a cheap low end chinese (that sometimes cost more) scope and not this jewel of performace ???? just when you listening the tick of a knob (like time base) seems to be something truly superior regardless !!!!
« Last Edit: May 15, 2013, 08:28:51 am by luca1000 »
 

Offline rf-loop

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #59 on: May 15, 2013, 08:46:02 am »
http://www.pa4tim.nl/wp-content/uploads/2010/11/tekgewoon.jpg this was my 2445, that had no auto button (as far as I can see). Never knew the 2445B was besides a bigger bandwidth so much different on other things too. Nice, thanks for the info.


Yes, this 2445 (without A or B) version do not have. Also internal  is totally different in more new veresion of 2445.
Last versions of 2445B have (afaik) 200MHz BW. (and there may still be 150MHz label on front panel, it need somehow look serial number but I do not know exactly what time this change was. But If I remember right there is also 2445B where front panel text is 200MHz. )
« Last Edit: May 15, 2013, 09:47:41 am by rf-loop »
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 nctnico

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #60 on: May 15, 2013, 09:29:03 am »
Are you serious ? Never seen real auto on analog scopes but I have no analog scopes from after 1990. But does that set timebase, trigger and V/div and on a real analog scope. ? I'm curious, never knew this, please name a model.
The Tektronix 2400 series has it. On this Tek 2445A the button is right to the top of the screen:
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline PA4TIM

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #61 on: May 15, 2013, 09:52:44 am »
RF-loop, i once read there was something with a bandlimmit filter. Do not recall the precise types but if you remove that filter you get the higher bandwidth. That way some eby dealers rebuild 2445B models to 2465 or 2445A to B models ( can not recall that, it is domewhere in the Tekscopes group archive)
Some sold the scope as 200 MHz but still with the old graticul front, do the state a different BW.
To bad it also happns the way around, they sell a 2445A with the B front. And some mod the 2445A ino a B and also exchange front. So you think you buy a real 2445B ( types are just an exale because, like I said, I can not remember the excact types) but be carefull.

I had a beatifull 2445. That was realy spot on. But then I bought the Rigol, had a few 7000 scopes and a few 5XX ( and some more, and not enough space) so I gave the 2445 away.  After some time with the Rigol I really started missing it. It was allmost absurt accurate. But the Hameg filled that gap good enough. My 7704 has the fast puls response option so it's Tr is faster. 7000 are realy great scopes, in size and performance. To bad they are not as mechanical solid as the 24XX serie. ( very flimsy buttons and the plugin latch system is a joke, as is the powerbutton mechanism, changing lightbulbs is a nightmare)



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Offline Wuerstchenhund

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #62 on: May 15, 2013, 10:06:19 am »
I don't understand WHY the people (and I include me in this list) was think to choose a cheap low end chinese (that sometimes cost more) scope and not this jewel of performace ????

I can of course only speak for myself (and I never bought low end scopes until last week, and even this is more of a 'throw away' scope and not my primary scope), but instantly the problem for me would be the very limited signal analysis capabilities (no math, no FFT), no proper storage, no segmented memory, no way to capture waveform data and transfer them onto a computer etc. Plus it's very big, and likely approaching the end of its lifetime.

A new low end scope is at least new (and usually comes with warranty), takes much less space and consumes less energy. It also offers much more measurement functionality, and allows you to capture (and externally analyze) waveform data. On some of them (like the very cheap Siglent SDG1102CNL I bought as a 'throw away' scope last week) you can even use the captured waveform data as input for an AWG (Arbitrary Waveform Generator) which then 'plays back' the captured signal. This can be great for takeing a 'sample' from a real-life signal which then can be used as simulation in your lab.

If all you want to do is being able to look at some waveforms then all this doesn't matter of course, and if you can get a decent analog scope for little money then why not? But I would not recommend investing much money in a scope which is a) very old and b) where you might quickly outgrow it's very limited capabilities.

Quote
just when you listening the tick of a knob (like time base) seems to be something truly superior regardless !!!!

Indeed, many of these old scopes demonstrate a very high build quality and workmanship. But at the end of the day the question is what you want to use a scope for (as a collector's item or a tool).

I'm certainly not against analog scopes in general (I've used them long enough myself), but the fact remains that, outside any nostalgic dwelling in the past, analog scopes are dead technology, and this for very good reasons. Despite DSOs occasionally being bad-mouthed by some oldtimers that are essentially stuck in the past or never learned to handle a DSO properly, the simple fact is that you can go into any high tech lab around the world which works with highly complex and sophisticated signals, and you will only find DSOs there (and believe me, had analog scopes any advantages that are still relevant then they would still be used there). Of course DSOs do have their limitations, but that is equally true for any test instrument. If you don't understand these limitations you're f'ed, no matter if its digital or analog.

But the truth is that the capabilities of analog scopes are very limited and that the majority has long past its zenith in terms of life time, which means that you may up ending with a scope which quickly becomes a project in itself instead of a tool you can just use for getting on with your projects. A scope project is not necessarily a bad thing if you're looking for this sort of projects (there are many people restoring old analog scopes which is great) or if you're at least prepared for that. I'm not sure this is the best thing for a beginner, though.
« Last Edit: May 15, 2013, 10:17:45 am by Wuerstchenhund »
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Offline rf-loop

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #63 on: May 15, 2013, 10:13:32 am »
RF-loop, i once read there was something with a bandlimmit filter. Do not recall the precise types but if you remove that filter you get the higher bandwidth. That way some eby dealers rebuild 2445B models to 2465 or 2445A to B models ( can not recall that, it is domewhere in the Tekscopes group archive)
Some sold the scope as 200 MHz but still with the old graticul front, do the state a different BW.
To bad it also happns the way around, they sell a 2445A with the B front. And some mod the 2445A ino a B and also exchange front. So you think you buy a real 2445B ( types are just an exale because, like I said, I can not remember the excact types) but be carefull.

I had a beatifull 2445. That was realy spot on. But then I bought the Rigol, had a few 7000 scopes and a few 5XX ( and some more, and not enough space) so I gave the 2445 away.  After some time with the Rigol I really started missing it. It was allmost absurt accurate. But the Hameg filled that gap good enough. My 7704 has the fast puls response option so it's Tr is faster. 7000 are realy great scopes, in size and performance. To bad they are not as mechanical solid as the 24XX serie. ( very flimsy buttons and the plugin latch system is a joke, as is the powerbutton mechanism, changing lightbulbs is a nightmare)

What 2445 models I have owned they are mainly from original user and all they have been "untouched" and if there have been service before me, all have done they own lab or tektronix lab. Also before me they all have been in cyclic unbreaked calibration whole they life until sold out as surplus.  Still have some 2445, 2445A and (2445B not exactly sure becouse time ago I sold some these),  2465, 2465A-DM and 2465B etc.

I know 7000 also becouse I have some these. Perhaps most nice is one true double beam unit, and then one  400MHz with storage and one 7854 with signal digitizing including 7854 waveform calculator keyboard. etc. And then some more usual models.  These are not anymore in active use, just stored. But sometimes I run these for keep then alive.
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 rf-loop

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #64 on: May 15, 2013, 10:48:37 am »
Also there is one aspect.

If someone want make example new Tektronix 2465B with CT opions etc.
Its price is - more than high. I can not imagine how extremely high it is. Then can ask, who want buy them. With this aspect, of course world of high class analog oscilloscopes is dead.

Professionals and higher level hobbyists know limits of digital and analog oscilloscope also. Specially low end digital oscilloscope user NEED know his equipment for avoid troubles.

What I'm some amount worry is entry level hobbyists who do not know enough and then he can not understand why and what this digital scope show. Then is lot of talking that is this normal or fail and why it so like this and so on.  For good acceptable results with unknown signal there need understand and know how these work and how to avoid false. Aliasing is one thing what really need understand and understand how oscilloscope relly work with different settings and what it may do with unknown signals. Example slow horizontal speed, low samplerate but still analog front BW fully open.  Samplerate 1MSa/s but front end open so that all from 0 to 300MHz can go to ADC... then wonder what hell is on my display and what is my real signal under test and what information is just garbage. Then ask, is this my scope bad or do it have some fail. How this crap can sell and who repair this my scope.

Shortly, for many peoples. Know your equipment, know basic fundamentals. It need learning work but is is only way to get other than just false measurements. With analog scope it is more "safe" and these traps which can drop is less.

(about Siglent, yes, in its price class ok for many use and many nice features and building quality very good in its price class and acceptable if do not take price to count...and even protective real glass front of TFT hehe... wait a moment after I get SDG5000 for tests)
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.
 

Offline luca1000

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #65 on: May 15, 2013, 10:56:48 am »
I'am not an expert (I understand only about audio D/A converter that is different).

But for my opion the REAL limit of these digital scope is resolution (8 bit 256 point are not enough).

When I see a sine signal on the analog like 2445 I see a VERY perfections , no any defects about the scope, only the defect of the signal (if there are).

When I see on digital scope (expecially on cheap scope, but not only) I see only some points and the result is not accurate.

Ex: on a screen of 800x600 (256 points are not suffcient to fill 600 points and interpolations or other is a compromise). And apart this, 1 G sample is another compromise that cause inperefect result.

In short if you want Quality and accurate result (>10 Hz, periodic signal) I think no way better then analogue you can find.

when I see  a periodic signal (>10 Hz and < 50 Mhz) the result of a analogue 2445 is a REAL result, but with a digital scope < 700 Euro the result can be false and in all case is a compromise (some points no perfect reconstructions like analogue) and when you compare the result, you can be sure that analogue tell the true.
« Last Edit: May 15, 2013, 10:59:04 am by luca1000 »
 

Offline Wuerstchenhund

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #66 on: May 15, 2013, 11:23:50 am »
What I'm some amount worry is entry level hobbyists who do not know enough and then he can not understand why and what this digital scope show.

I agree, but the way around that is for them to learn and understand their DSO and how it works.

Quote
Shortly, for many peoples. Know your equipment, know basic fundamentals. It need learning work but is is only way to get other than just false measurements. With analog scope it is more "safe" and these traps which can drop is less.

Yes, but the proper way for a beginner is to try to understand these limits in the first place and not try to avoid them, especially if EE is supposed to one day become more than an aoocasional hobby.

Quote
(about Siglent, yes, in its price class ok for many use and many nice features and building quality very good in its price class and acceptable if do not take price to count...and even protective real glass front of TFT hehe... wait a moment after I get SDG5000 for tests)

As I said in another thread, I really didn't expect much when I ordered my SDS1102CNL scope, but I was really positively surprised (build quality is good, as you say the LCD is protected). My only critics would be the low display resolution (not a real problem, but could be a bit better), the lack of 50 Ohms switchable inputs, and the very simplistic persistance mode (no grading). But again, considering the price, this thing is really good.

And I'm probably well known for not being a great fan of Chinese scopes or entry level scopes in general  ;)
« Last Edit: May 15, 2013, 11:25:44 am by Wuerstchenhund »
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Offline Wuerstchenhund

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #67 on: May 15, 2013, 11:58:18 am »
I'am not an expert (I understand only about audio D/A converter that is different).

But for my opion the REAL limit of these digital scope is resolution (8 bit 256 point are not enough).

When I see a sine signal on the analog like 2445 I see a VERY perfections , no any defects about the scope, only the defect of the signal (if there are).

When I see on digital scope (expecially on cheap scope, but not only) I see only some points and the result is not accurate.

Be careful, this is not the same as listening to audio! And yes, for scopes 8bit is generally more than enough even for very high frequency signals (and for the few cases it isn't there are 12/14bit scopes available as well). And while you may think that the signal you see on an analog scope is free from influence, that is not true as even analog scopes suffer from imperfections like frequency-dependent distortions and non-linearities.

Quote
Ex: on a screen of 800x600 (256 points are not suffcient to fill 600 points and interpolations or other is a compromise). And apart this, 1 G sample is another compromise that cause inperefect result.

You ignore that not all of the 800x600 screen is used for displaying data points, it also contains the scale and other data like the settings or measurements.

And 1GSa/s is plenty of data for signals say up to 100MHz.

Quote
In short if you want Quality and accurate result (>10 Hz, periodic signal) I think no way better then analogue you can find.

I'm sorry but I'm not sure you really know what you're talking about. Please define what you mean by "quality", as again, this is not the same as listening to music.

Quote
when I see  a periodic signal (>10 Hz and < 50 Mhz) the result of a analogue 2445 is a REAL result, but with a digital scope < 700 Euro the result can be false and in all case is a compromise (some points no perfect reconstructions like analogue) and when you compare the result, you can be sure that analogue tell the true.

I get the impression you don't fully understand how a scope is used, and you bang on points that are generally of little relevance in most applications. It doesn't matter much that a DSO builds up the waveform from little points while the analog scope 'plots' the signal as it is. A scope is all about displaying information. However, the additional 'fidelity' on an analog scope does not necessarily give you additional relevant information. But with most analog scopes the waveform you see is all you get. On a DSO, the waveform display is just a small part of the information you get, aside from a bunch of additional parameters that would take quite a lot of effort or are simply impossible to get from an analog scope.

I think the term 'oscilloscope' for a DSO is a bit misleading, as it's much more than that. A DSO is really more of a signal analyzer than a traditional scope, albeit it can also be used in this function.
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Offline PA4TIM

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Re: Owon SDS7102 or Tektronix TBS1062 or TDS1002
« Reply #68 on: May 15, 2013, 12:12:27 pm »
Just make it clear, I'm not against DSOs. I'm agains cheap DSOs operated by people who do not know the limitations. Like I'm against cheap tools in general. Mechanicl snd electrical. If I buy something I wait until I can buy a good tool ( or camara, TV, ect) and I kep using them very long. If they brek I first repir them and exchange them only if they become to old to function. In the long run this is the cheapest way. ( at least for me the last 30 years)
But I become a bit recalcitrant if people talk bad about my precious babys. Analog scopes are history, that is sure.

Not all DSOs are alike. The very high end scopes are in a way more related to analog scopes as to cheap DSOs. And the problem with the hybrids was they were so good you indeed almost never needed the ( whole) analog part. Most times the analog amplified signals were send to the CRT direct or to the ADC nd then to the CRT so you ould add nice functions. i have a hybrid Tek SA who does this.

The difference between high end and cheap scopes is the way they sample. If I would use the output of an anlog sample plugin and send the output of that to an ADC/ uP and LCD display you get the idea. ( btw, using a 132 and 1S1 makes that possible, something like this and will be for me a future project) Much higher resolution and less dead time. The ADC only needs to deal with rather low frequency signals. But in modern high end ( many GHz) sample scopes the sawtooth, stepper ect is made digital intstead of analog. And that is not how a siglent, Owon, Rigol, Agilent 3000 ect work.
( in a very raw nutshell)

I'm a scope collector too so I love to restore and play with analoge scopes.

I know the limitations of both DSO and analog scopes. And like I said in an other topic. If I had to keep 1 scope it would probably be the Hameg DSO ( but I hope I never have to choose, because I'm in love with my 547) if I had to choose between the DS1102E it would be an analog scope for sure, would not have to think more as a second)

This 547 ( and even nicer but I do not have one, the 556) scope including my plugins can do things most DSOs can not even dream of.
- most sharp trace I've ever seen. ( btw the 24XX have , for an analog scope has rather fluffy traces)
- i can measure up to 5 GHz
- measure things with 10 uV/div resolution
- measure very high voltages
- it has several differential plugins, for AC, DC, high voltage, low voltage ect
- high DC offset measurements, the Z plugin can do upto 2000 divisions offset ( max 200V) , no DSO can do this)
- measure transistor timing ( R plugin) ( ok, not very usefull today, but it can do it)
- with the Opamp plugin you can do the wildest things like integration, preamplifiction, measure capacitance ( managed to come down to 1 pF/div), meaure BH curves ect. Just two very good tube opamps in one unit with a buch of in and outputs. Real cool, a build in breadboard in your scope.
- it has a very good delay option and two timebases. Excellent calibrator, 1 mV to 200V
- upto 4 channels, very much trigger options and very good triggering ( you can show two traces and each adjust their own trigger. This I find the biggest downside of a DSO ( but maybe in the high end they have  dual timebase and dual trigger)
- whole lot of input and output connectors
- It does TDR with high resolution using the 1S2
- it can be used as a SA and the 556 can do time domain and frequency domain at the same time ( So a realtime SA and realtime normal trace at the same time, upto 8 traces, Williams used that in appnotes)

The 7000 4 slot can do even more because you can use vertical and horizontal plugins in all slots, so make things like raster displays.

( downside, the 547 works very good as a heater and it gives a new definition to large, including the scopemobile and no cursors, readout ect and that for sure is the best thing of DSOs)
If you do, like most, do only digital then a DSO is first choise. But I'm analog.



www.pa4tim.nl my collection measurement gear and experiments Also lots of info about network analyse
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