Opinion - Oscilloscope : Digital vs Analog

[iphone]

Hi guys.

Need you opinion n comments on the PRO n Contra about Digital Oscilloscope vs Analog Oscilloscope.

I need to buy one unit for my project n my budget around RM6k (Malaysian currency) or USD1.5k total package.

So anyone can recommend to me what brands and specs should be great.

I already do some window shopping on this matter but forgot the brand name ( I will update later) but it's digital with data output to PC (USB) n 200Mhz, 2 channel.

Hope can get some guidedance before buy it. Hope I make a good decision n not regret later ( USD1.5k is too much for me).

Thanks in advance.

[solutions]

What are you planning to do with it? It's all about mission profile as far as pros vs cons of analog/digital

[iphone]

I'm doing some electronic gadget.

The gadget will cut the AC supply at zero crossing. I will use the oscilloscope to know  and to calculate time for PIC to cut off the AC supply.

This gadget not need the high end oscilloscope, but I have given budget to buy oscilloscope so I need to buy good oscilloscope not only for this project but for future project too. Like one stone kill 2 birds.


I need some medium - pro version of oscilloscope that suit the budget of USD1.5k.

So any suggestion  for the oscilloscope for that budget ?  Digital vs Analog ?

tq

[mylogin]

@1.5KUSD you can buy Agilent, Tektronics 100MHz digital scope.  they are much better than Analog scope for slow events.  (note: the cheap models can store only 10k points)  if you need deep memory (such as for MCU, serial comm. asyn. digital signals) try "RIGOL"  they are much cheaper and good quality.  they all come with extra functions such as FFT, frequency counter, RMS voltage ...etc.,

It is difficult to use the analog scope in slow or non-repeat signal events. unless you have analog-storage,  I own 5 analog scope, but nowadays I use Digital scope with deep memory most of time .

[solutions]

Saelig has a  pretty nice set of discounts right now.  You can get a combo logic analyzer/scope and have enough left in your budget for an additional analog scope  See the banner here http://www.saelig.com/miva/merchant.mvc?Screen=CTGY&Store_Code=SOS&Category_Code=MFR00068&offset=12 or the latest Elektor magazine.

[LabVIEWguru]

Hey Iphone - I'm playing with Direct Digital Synthesis, and there is a very simple "zero crossing circuit" using an opamp and a couple resistors. Output is a square wave as input crosses "0"

Perhaps this, tied to an interrupt or port pin would be faster than trying to time a zero crossing?

http://freecircuitdiagram.com/2008/09/02/single-supply-zero-crossing-detector/

I purchased my Tektronix 100 Mhz Digital Storage Oscilloscope many years ago, and wouldn't trade it for anything. I see them on Ebay now (older CRT types) for almost nothing. Make sure you get a nice set of probes. They can be expensive. I just bought a set a year or so ago from Ebay, about $40.00 

[oldvan]

Tektronix 2440 Digital here, I love it but lust for a modern LCD version some day. 

Digital is a lifesaver for capturing non-repetitive events.

[iphone]

Hey Iphone - I'm playing with Direct Digital Synthesis, and there is a very simple "zero crossing circuit" using an opamp and a couple resistors. Output is a square wave as input crosses "0"

Perhaps this, tied to an interrupt or port pin would be faster than trying to time a zero crossing?

http://freecircuitdiagram.com/2008/09/02/single-supply-zero-crossing-detector/

I purchased my Tektronix 100 Mhz Digital Storage Oscilloscope many years ago, and wouldn't trade it for anything. I see them on Ebay now (older CRT types) for almost nothing. Make sure you get a nice set of probes. They can be expensive. I just bought a set a year or so ago from Ebay, about $40.00  

Actually I plan to use 2 diode n 1 resister after transformer and PIC detect OV after diode (once it voltage < diode forward voltage) and calculate (delay) before AC reach the real 0 crossing. So I just use 2 components.

In my design (commercial product), I will try use smallest no component and to make low cost and low complicity to archive better cost saving.

Anyway, thanks to all friends.

[solutions]

You do realize that you can do AC zero cross with just a SINGLE current limiting resistor attached to a GPIO pin on the PIC?  The ESD diodes in the PIC will clamp the voltage on both the positive and the negative side of the waveform.  From there, you can easily figure out the zero crosses by timing the one/zero logic transitions of the positive half sines.  There's a Microchip app note about that one somewhere.  It's non-isolated, but since you are on the secondary of the transformer, that probably no longer is an issue for you.

[iphone]

You do realize that you can do AC zero cross with just a SINGLE current limiting resistor attached to a GPIO pin on the PIC?  The ESD diodes in the PIC will clamp the voltage on both the positive and the negative side of the waveform.  From there, you can easily figure out the zero crosses by timing the one/zero logic transitions of the positive half sines.  There's a Microchip app note about that one somewhere.  It's non-isolated, but since you are on the secondary of the transformer, that probably no longer is an issue for you.

Solutions, thanks for tips. Great tip.

I plan to use PIC12Fxxx ((8 pin) for my project and maybe your tip can be implement in PIC12Fxxx ( I just need to check datasheet).

Offtopic: I need to write  using assembly language as the PIC12Fxxx has small flash. So can anyone suggest me the right software to learn ( I mean using graphic/icon method like flowcode but flowcode generate C language but I need software which can generate assembly language straight away. Long time ago, I remember in this forum, there is software like that but I forgot the name. Any help will be appreciate.)

Thanks again.

[optikon]

You are better off with a digital scope..

Digital PRO - Capture one shot events.
Digital PRO - memory storage - better "post processing" - display etc..
Digital PRO - color screens, looks good, less bulky
Digital PRO - Removable storage - thumb drive, disk, CD or something to write a screen capture.. very nice.

Digital CON - more expensive compared to similar performing analog

I own a Rigol and Tek digital as well as numerous analog and I have to say there is nothing I do that cant be done with the digital scope.
I just can bear to throw out the analog scopes though. 

[Old_but_Alive]

I bought a DSO for $500 a few months ago, and am very happy with it.

after googling, some of the comments seem to prefer rigol units, but i still bought it.

The chinese supplier has been very helpful and responsive.

The only issue is that the software which runs on a PC is XP, not win7.

http://cgi.ebay.co.uk/Uni-trend-UTD2102CEL-1GS-s-Digital-Storage-Oscilloscope-/290495777806?pt=Motors_Automotive_Tools&hash=item43a2e5cc0e

p.s. pickit2, dont flame me, its not an advert, just my experience


Mike

[SBW]

A week late, but:
Digital CON: digital scopes rarely have an anti-alias filter which tracks the timebase setting.  Because of this, high frequency signals will look like a low frequency signal if you use a slow timebase setting.  You can end up chasing a non-existent kHz oscillation that is actually MHz pickup if you forget to change the timebase to verify that the displayed signal is the fundamental and not an alias.

Also, because they are responding to the full scope bandwidth no matter what the timebase setting, you have more noise than if the input were filtered.  This also applies to analog scopes, but they often have lower noise levels to begin with, so it is less of an issue.  (For really weak low-frequency signals, the old 7a22 analog plug-in is great, with its 10 microvolt/division sensitivity, differential input, offset adjustment, and selectable filtering.)

But those more more things to be aware of than reasons to go analog.  I have Tek 7000 series analog, HP 54512b (monochrome) digital, and HP 83480a/83483a 20 GHz sampling scopes on my bench, and I can not remember the last time I turned the analog scope on.  If I need the 7a22, I'd probably connect the 'signal out' from that scope to my digital scope to view it.

There is a tremendous difference in utility between monochromatic and color digital scopes.  This is more than just looking pretty: it is a real time and confusion saver to color code your probes to match the trace colors.  With a monochromatic scope, you are always wondering which trace corresponds to which input.  You can figure it out by disconnecting the probe from the circuit, or from the scope, or by toggling the trace off and on, or by changing the offset, but it is so nice to advance beyond that.

[Triodethom]

I bought a DSO for $500 a few months ago, and am very happy with it.

after googling, some of the comments seem to prefer rigol units, but i still bought it.

The chinese supplier has been very helpful and responsive.

The only issue is that the software which runs on a PC is XP, not win7.

http://cgi.ebay.co.uk/Uni-trend-UTD2102CEL-1GS-s-Digital-Storage-Oscilloscope-/290495777806?pt=Motors_Automotive_Tools&hash=item43a2e5cc0e

p.s. pickit2, dont flame me, its not an advert, just my experience


Mike

Are you using it for mainly audio and am band work ?
 

[BharatSujanani]

We have also purchased Digital storage oscilloscope only in 620US$ from india.

Company website is "http://www.falconindia.biz/"

Model is "DSO-050C5: 50 MHz 500 MS/s with FFT Colour Digital Storage Oscilloscope"
It is working good, with lcd screen and 2 channel with storage.

[VolkD]

Comparison of digital and analog Sun oscilloscope can be a little misguided, because these are two completely different instrument. The same is the name and the fact that both can display signal format. After a few analog oscilloscope can be set is better because the signal current track changes. In digital, we must wait to re-implement the FFT routines.
On the other hand, has a digital oscilloscope memory effect that is present in analog oscilloscopes are exceptional.
I have bought a digital oscilloscope to the fair in Friederichshafen for € 330 mark Rigol DS1102DE. Later purchased another probe for logic analyzer digital signals.
I think it was a good buy.

[Danish]

My recommendations:

Entry level analog: Tektronix 2225.

High End analog: Tektronix 2465B.

All round digital: HP/Agilent 54600 series.

I need both analog and digital scopes for my work. Each with its strengths and weaknesses.

[PICker]

Virtins DSO are very good entry level devices:
http://www.virtins.com/VT-DSO-2820.shtml
Cheers

[PM3295]

I am also in the camp of using both analog and digital scopes. Apart from the HP and Tek analog scopes recommended here by others, there are many good analog scopes from Hitachi, Iwatsu, etc. that can often be picked up for next to nothing on eBay. I managed to get a 400 MHz analog Iwatsu readout scope for only $150 a year ago. Nobody else was even bidding on this at the time.

[zac]

I still have a Tektronix 2246 100 mhz analog scope with readouts from the late 1980s that I occasionally use, but I would not buy an analog scope now because the DSO/DPO's can do everything the analog scope can. 

The Rigol models are probably the best value:

http://www.batronix.com/shop/rigol/MSO1000Z.html

http://www.batronix.com/shop/rigol/MSO2000A.html

There is a modification available to enable additional functions/higher bandwidth on some rigol models:

http://freneticrapport.blogspot.com/2013/07/raspberry-pi-rigol-ds2072-200mhz.html

Rigol also had a scope that interfaced with a PC over USB that was pretty good, but they stopped supporting it and the software is stuck only working properly with window XP.  You may be able to find a good deal on ebay: 

http://www.batronix.com/shop/oscilloscopes/Rigol-VS5062D.html

Agilent/Keysight also has a similar (but still supported) usb scope that works very well:

http://www.keysight.com/en/pd-1369621-pn-U2701A/usb-modular-oscilloscope-100-mhz?cc=US&lc=eng

http://www.ebay.com/itm/Agilent-HP-U2701A-USB-Modular-Oscilloscope-IVI-Instrument-Drivers-100-MHz-/151441141978?pt=BI_Oscilloscopes&hash=item23429870da

I prefer using the larger higher solution display on a PC than the smaller low res (typically 800x480) displays found on most low to medium priced scopes. 

Another possibility is the older but still very capable Tekronix DPO's such as the TDS754D which can be occasionally found on ebay for about $1000 in good shape. 

http://www.testequipmenthq.com/datasheets/TEKTRONIX-TDS754D-Datasheet.pdf

One downside to older equipment like this is no usb port so data can only be transferred by gpib or floppy disk. 

[sohel]

Dear all.

i am planning to buy RIGOL MSO1104Z for digital power electronics . please share your experience which will help me to decide.

Regard's
 

[dezso]

Excellent subject my friends, I my self are planing to get the RIGOL MSO1074Z, unfortunately the CAD$ price is way down at the moment, might just need to suck it up.
Read many good review for the 1054Z and 1074Z, my current HP16500C w/16532A&16510B costed me 1000's 10 years ago and it's still a 50lb piece of junk.
Anyone have used one of the upgrade hack's for the 1054 or the 1074, does it still works ?

Back to your question, read this article from PICOTech , I myself never been a big fan of Analog scopes, most cheap low bandwidth scopes for illustration purpose only, hard to measure anything, triggering is a pain.
As for the MSO1104Z, great futures, do you really need 8/16ch LA, my current machine have 32CH 1GHz input, I don't remember ever using more than 4 channel, maybe 5 at max.





dezso:

[sohel]

Thanks,

I will order DS1054Z when china come back from there holiday.

[dezso]

Where are you planing to order it from?

dezso:

[sohel]

"Where are you planing to order it from?"

this is the main problem. china is near by me and shipping cost will be low compared to USA.  but afraid about original or clone.