I want to apologize in advance. I see lots of threads dealing with this topic, which are very helpful, but none specifically answer my question.
I am looking at purchasing an oscilloscope. Specifically I am looking at the Rigol DS1052E. It costs about $400 (not too expensive) and seems to get good reviews. I've never used one before but have always wanted one. I want to learn more about them and use it in servicing my tube amps ( Bob Latino ST-70 and ST-120s). I also intend building a preamp. I know I could get a used oscilloscope cheaper but as my wife says I have more money than brains.
The specs are here:
DS1052E::RIGOL
I am not sure how to read the specs and my question is this: The voltages in the amps are around say 500v. The input on the scope has a limit of 300v. There is a 10x attenuation switch on the probe. Can I use this oscilloscope to measure voltages etc. in the amps? Anything else I should think about? Is this a reasonable scope for the intended purpose?
Appreciate your thoughts.
I am looking at purchasing an oscilloscope. Specifically I am looking at the Rigol DS1052E. It costs about $400 (not too expensive) and seems to get good reviews. I've never used one before but have always wanted one. I want to learn more about them and use it in servicing my tube amps ( Bob Latino ST-70 and ST-120s). I also intend building a preamp. I know I could get a used oscilloscope cheaper but as my wife says I have more money than brains.
The specs are here:
DS1052E::RIGOL
I am not sure how to read the specs and my question is this: The voltages in the amps are around say 500v. The input on the scope has a limit of 300v. There is a 10x attenuation switch on the probe. Can I use this oscilloscope to measure voltages etc. in the amps? Anything else I should think about? Is this a reasonable scope for the intended purpose?
Appreciate your thoughts.
It looks like 300v is an overload rating, like it will withstand 300v buts its not a good idea. My old HP scope has a 40 volt measurement limit so combine that with a 10:1 probe and you can do up to 400.
It looks like a decent beginners scope. The 8 bit resolution is low if you plan to do any serious FFT readings but you can get a PC sound card for that.
It looks like a decent beginners scope. The 8 bit resolution is low if you plan to do any serious FFT readings but you can get a PC sound card for that.
I have that scope. If you are interested, there are software hacks available to turn it in to a 100Hz scope (50 and 100 Hz scopes are identical internally, it just requires a software switch by reloading the firmware). As mentioned, the 8 bit resolution is somewhat limiting. I use it to make measurements and to store wave forms etc. If you can stretch it, purchase an old analog scope as well (or at a later date) as it will have better screen resolution for determining oscillation, and for seeing a truer representation of the waveform (distortion etc).
I have an old Tek 2225 that I had first, thinking I would replace it with the Rigol. Rather than replace, I think they compliment each other well for the reasons listed above.
I have an old Tek 2225 that I had first, thinking I would replace it with the Rigol. Rather than replace, I think they compliment each other well for the reasons listed above.
Chirsh,
Thanks for the input. I've been reading up on digital scopes and note the limits of 8 bit resolution. I'm now thinking of an analog scope, specifically this Tenma (MCM Electronics):
Tenma 20MHz Oscilloscope with Function Generator | 72-6805 (726805) | Tenma
Any thoughts on this one? Recall I want to be measuring tube amp voltages.
I see in the specs it can measure up to 300V. The amps have in the region of 500V. Presumably the 10x probe would reduce that to say 50V making it acceptable to the scope?
Appreciate any thoughts...
Thanks for the input. I've been reading up on digital scopes and note the limits of 8 bit resolution. I'm now thinking of an analog scope, specifically this Tenma (MCM Electronics):
Tenma 20MHz Oscilloscope with Function Generator | 72-6805 (726805) | Tenma
Any thoughts on this one? Recall I want to be measuring tube amp voltages.
I see in the specs it can measure up to 300V. The amps have in the region of 500V. Presumably the 10x probe would reduce that to say 50V making it acceptable to the scope?
Appreciate any thoughts...
the specs say the sensitivity is 5mv to 5 volts per division. There are 8 squares or divisions on the screen, with a 10x probe the max you will be able to see is 400 volts. So you will not be able to measure DC voltages higher than 400 VDC with a probe but that doesn't mean you cannot measure the AC ripple on the high DC voltage lines. You will have to check what is the maximum voltage the probes can handle AC + DC. There is a probe on that web site that has a max of 600 volts AC + DC. So that should work for you. Bear in mind that at 605 volts the probe wont probably fail but will be good till 700 or 800 volts.
Do the digital math.
8 Bit vert resolution on FFT spectrum analysis will be accurate down to around
-50dB ref carrier..typ for CM/Diff work on PSU filters....but one will see ghost signals lower than this; is just spurious rubbish and not accurate. Dissecting an audio signal, this equates accuracy to the 0.3% distortion level. There is a learning curve attached to digital scopes to understand limitations and what they can do.
The adage: Never get rid of a good analogue scope for a digital one. Both have their advantages on the bench.
Wanna to go -90dB down ? (0.003% thd level )..then 12-16Bit + extra cost.
richy
8 Bit vert resolution on FFT spectrum analysis will be accurate down to around
-50dB ref carrier..typ for CM/Diff work on PSU filters....but one will see ghost signals lower than this; is just spurious rubbish and not accurate. Dissecting an audio signal, this equates accuracy to the 0.3% distortion level. There is a learning curve attached to digital scopes to understand limitations and what they can do.
The adage: Never get rid of a good analogue scope for a digital one. Both have their advantages on the bench.
Wanna to go -90dB down ? (0.003% thd level )..then 12-16Bit + extra cost.
richy
Not a bad idea, but they are not the best Tek scope to work on and repair. I would go for a 22XX series as a first scope.
Anyway I think the OP was after a digital scope and the Chinese units seem to offer good value for money. Although I have never used a Chinese one I would prefer a second hand Tektronix or HP scope.
Cheers Matt.
Anyway I think the OP was after a digital scope and the Chinese units seem to offer good value for money. Although I have never used a Chinese one I would prefer a second hand Tektronix or HP scope.
Cheers Matt.
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I'm going to agree with Steve about the Tek 465B. Over the years I've owned, at one time or another, just about every scope that Tek made with the exception of the newest TDS series. And I do not like any of the non American made scopes, excepting perhaps, the Kikusui's and the Leader's. Both Japanese.
The Tek 2200 series were the first of the low cost units to be introduced. Corners were cut especially in the physical construction and the power supply. The universal switching primary supply has a history of failures and IMO is unreliable. And the more expensive 2400 series also has their problems. The hybrid modules go bad, especially the horizontal amplifiers.
Yes, the 465B is an older model, but it will outlast the 2200 series by a large factor. In fact, it already has. And having worked on most all of them, the 465s/475s are not that bad to service. And there is still plenty of surplus parts around. My only gripe with them is that the spot size was never as sharp as the older models. I once had a long talk with a Tek employee about that, but that's another topic in itself.
The Tek 2200 series were the first of the low cost units to be introduced. Corners were cut especially in the physical construction and the power supply. The universal switching primary supply has a history of failures and IMO is unreliable. And the more expensive 2400 series also has their problems. The hybrid modules go bad, especially the horizontal amplifiers.
Yes, the 465B is an older model, but it will outlast the 2200 series by a large factor. In fact, it already has. And having worked on most all of them, the 465s/475s are not that bad to service. And there is still plenty of surplus parts around. My only gripe with them is that the spot size was never as sharp as the older models. I once had a long talk with a Tek employee about that, but that's another topic in itself.
I agree completely about the 2200 series. The power supply is pants. Other than that they are not that bad. The PS problems are very easy to repair and they use standard ie non Tek specific parts apart from the tripler, which is a pain on all of the Tek scopes but easily substituded
The later I believe Sony/Tektronix ones with plastic handles are to be avoided.
The 465 is a really cracking scope. A 465B with the dmm and counter is lovely. Just a pain to work on IMO. A bit big and really hold their price when a 2235 gets you 99% of the way at half the price.
Any US scope is preferable to a Chinese thinge.
The later I believe Sony/Tektronix ones with plastic handles are to be avoided.
The 465 is a really cracking scope. A 465B with the dmm and counter is lovely. Just a pain to work on IMO. A bit big and really hold their price when a 2235 gets you 99% of the way at half the price.
Any US scope is preferable to a Chinese thinge.
Yep agree with all that.... I have had a few 2215's donated to me which all turned out to have been freebies due to non functioning PSU's. All were easily repaired but they have dim, fuzzy traces. Usable but poor. I kept just the best one out of them. The 4** series are much better and I also have a very nice 453 with only a few hours use! Very sharp bright display but tiny screen.
My British S.E. Labs scope is my favourite though... In use all day every day for about 15 years and not one problem. Ever. And I bought it second hand! Hope this peon of praise does not sound it's death knell!
Also have one of the Cossor (Raytheon) CDU150's that were sold off cheap by the lorry load some 15 years ago by the military. Made in Essex U.K. Very good performance and loads of facilities but run alarmingly hot! You would think they were valved by the temp they run at.... Mine packed up after several years good service and I just haven't got round to fixing it yet.
I really don't like digital scopes personally.... I nearly sent a batch of very high end Agilent ones back as faulty (noisy) when we got them at a defence contractor I was working for at the time.... turns out they were supposed to be that noisy... apparently
My British S.E. Labs scope is my favourite though... In use all day every day for about 15 years and not one problem. Ever. And I bought it second hand! Hope this peon of praise does not sound it's death knell!
Also have one of the Cossor (Raytheon) CDU150's that were sold off cheap by the lorry load some 15 years ago by the military. Made in Essex U.K. Very good performance and loads of facilities but run alarmingly hot! You would think they were valved by the temp they run at.... Mine packed up after several years good service and I just haven't got round to fixing it yet.
I really don't like digital scopes personally.... I nearly sent a batch of very high end Agilent ones back as faulty (noisy) when we got them at a defence contractor I was working for at the time.... turns out they were supposed to be that noisy... apparently
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