Help on Choosing my first Oscilloscope

[PA4TIM]

Smokey, you are right, i never thought I say that, i love analog scopes and have a bunch of them. I had a Rigol DS1102D and at that time I till needed my analog scopes, for most for accuracy The Rigol was 3 % and not to recalibrate and if you move the trace across the screen measurement values varied very much. Also it missed a lot of things like glitsches and runts.
The analog scopes were 2 or 3% but I calibrated them to the highest level my equipement allowed and they showed all signals.

But since I have a 350MHz Hameg MSO I agree, there are only some very special thing left I "need "  an analog scope for. And this because i have a few Tek 7000 and a 547 with a lot of special plugins. So things like, a transistor risetime plugin, opamp plugin, 1 to 6GHz sampling, fast TDR, uV differential or differential slideback-comperator plugins ect.

For the topic starter, first buy a 20 to 50 dollar old analoge 50 MHz scope with two probes, play with it, learn to use it and when you know what you need buy a decent scope. If you aske around you probably can get a scope for free. I recently received a 50 MHz Tek 453, it was advertised to collect for free and nobody had reacted so the owner mailed me if I wanted it for my Tek collection ( and because it was a very early version ( 1966) i was happy with it. It still works exelent is in great shape and allmost no calibration was needed.

[zorthgo]

Hi Smokey, I have been using a simulator for my electronics I class. It is called Multisim 10.1. But I would like to start actually getting my hands dirty with some circuits. At least for me... Theoretical knowledge is fine and all, but I like to actually putting that knowledge to use.

I do have a question about the Rigol DS2000. If I buy the 72mhz (DS2072), would I be able to buy a software upgrade to make it into a 100mhz? I really wanted to stay around $500 - $600 but I guess I can go up to $800.

When you guys say that I could get an analog oscilloscope for less than $100, are you talking about those 20mhz scopes?


Ps. Hey Smokey, I actually enjoyed the rant!

[LoyalServant]

You can get quite a few analog scopes for less than $100 on ebay.
I regularly see 100Mhz scopes for less than $100.

Smokey: Agree with you with one caveat.
When I first got into electronics there were no digital scopes.....
Perhaps I am just an old fart but I abhor these new fangled DSOs with the "auto" button on them.
My personal opinion is that our grasshoppers learn to use analog scopes first.
I have seen too many punch the "auto" button and I cringe.....

Maybe I am just holding on too tight.... who knows.
Nevertheless, I do agree with your "rant" if that is what you want to call it.
I don't see why you would get flamed.

[vk6zgo]

I think the OP needs a DSO for what he intends to do.
This doesn't make a DSO the automatic instrument of choice for all things,however.

If you are using a 'scope as the primary instrument when troubleshooting & repairing a wide range of equipment,an analog Oscilloscope is a pretty hard act to follow.

With your 'scope showing an untriggered  continuous sweep in  DC coupled mode,you can get a good idea of  circuit voltages,check for the presence of desired signals,hum,spurii,etc.
If something looks a bit funny,you can then adjust the 'scope to look at it more closely.
With the same settings,set your trace to the screen centre line with no input,& you have a large display centre zero DC voltmeter,which is great for setting up nulls on bridges,etc.

None of the DSOs I have had anything to do with could run a continuous sweep of this nature without any input--maybe some newer ones can.

A comment I have made on a number of occasions,is about the inability of some DSO's to display a full field of an analog video signal without major distortion of the display due to aliasing.

The ability to display such a signal is an important requirement when looking for low frequency perturbations of the signal,such as AC hum,clamp pulse breakthrough,etc.
OK,analog TV is obsolete in many countries,but the same requirement exists for any HF signal which may be affected by low frequency artifacts.

The usual reaction is:-

"Silly OF!!",followed by a demonstration of how their DSO can display individual lines in a field.

Nice,but not what I was talking about!!

[zorthgo]

Ok Guys, I just pulled the trigger, and went with an Owon SDS8102. (I couldn't resist the specs)

Thanks for all the help!

[Dread]

Dave answered that previous question in his recent video.
No you cannot update a Rigol 2000 series scopes BW.
And that is a deal killer.
I know we have a lot of Ham Operators on this forum and 70MHz is just not going to cut it for the Hams, so now it's the full Monty Rigol on day one or look elsewhere.

[Dread]

Ok Guys, I just pulled the trigger, and went with an Owon SDS8102. (I couldn't resist the specs)

Thanks for all the help!

I think you will like the Owon, I have a 8202 and have been very happy with it.
BTW you should really get the Battery pack; it's a really good investment.
Enjoy your Owon and let us know what you think.

[Smokey]

Analog or digital, a scope is only going to be able to perform within its spec.  An analog scope is just a beam being deflected after all.  If you are getting aliasing you probably need more bandwidth or more memory.

I've never had any problems with untriggered roll on the 10 year old tek DSO in our lab.  If it weren't for the small sample memory, it would still be a decent daily driver.  The cheapy instek in the test stations is only 70mhz and does the job 90% of the time when I steal it for engineering.  Its far from a toy, even at the low price. 
About the only time I ever hit the autoset button is when I'm in window mode with some wacky zoom timebase and it would take more button presses to get back to a standard display.  Autoset as a crutch is lame, but just because its there doesn't mean you have to use it.

I do have mad respect for all the guys that were at the cutting edge back in the day with only analog scopes.  You really had to know your stuff and be able to infer all the stuff the scope couldn't tell you directly.

I think its kind of funny that RF keeps popping up in these discussions.  That is such a special case that needs specialized gear.  With integrated RF chips these days its easier to design than back in the day, but still not something a beginner would get into for a long time.

[vk6zgo]

Analog or digital, a scope is only going to be able to perform within its spec.  An analog scope is just a beam being deflected after all.  If you are getting aliasing you probably need more bandwidth or more memory.

In the example I quoted,it was definitely a case of lack of memory,causing the 'scope to reduce its sample rate to such a point that there were severe aliasing problems with the line rate & higher frequency components of the video signal

I've never had any problems with untriggered roll on the 10 year old tek DSO in our lab.

The problem I encountered with the DSOs I used,was that I could only get them to operate in this mode at very slow settings--any faster,& they reverted to the normal mode of operation.
At the really low speeds,any signal it encountered looked like my unmowed back yard!
Most of these would have been up to 6 years older than your ten year old DSO

 If it weren't for the small sample memory, it would still be a decent daily driver.  The cheapy instek in the test stations is only 70mhz and does the job 90% of the time when I steal it for engineering.  Its far from a toy, even at the low price. 
About the only time I ever hit the autoset button is when I'm in window mode with some wacky zoom timebase and it would take more button presses to get back to a standard display.  Autoset as a crutch is lame, but just because its there doesn't mean you have to use it.

I do have mad respect for all the guys that were at the cutting edge back in the day with only analog scopes.  You really had to know your stuff and be able to infer all the stuff the scope couldn't tell you directly.

In my opinion,the 'scope "being able to tell you stuff directly"is a double-edged sword,when it comes to beginners,as they don't seem to get a feel for what a waveform should look like.
You get screen grabs posted with all sorts of data on the page,but the basic things like volts/cm & time/cm seem to go astray,so it is hard to see what they are talking about,without an intimate knowledge of that instrument.

I think its kind of funny that RF keeps popping up in these discussions.  That is such a special case that needs specialized gear.  With integrated RF chips these days its easier to design than back in the day, but still not something a beginner would get into for a long time.

RF is hardly a "special case" for many people who either make their living out of Radio equipment,or have Ham Radio for a hobby.
RF,as it affects "digital people" is mainly UHF & above,but to the rest of us,RF starts where AF ends.

"Hams" particularly,have frequency allocations  from 1.8MHz up to tens of GHz.
Obviously,the top end of that range,is not really Oscilloscope territory--more Spec An work,& fairly fancy ones too.

In HF & VHF,'scopes are often used for signal tracing,etc,& needing to see a signal around 147MHz is fairly common.
100MHz analog Oscilloscopes can display RF signals of up to around 200MHz,although,obviously their sensitivity & calibration can no longer be relied on.
If it comes to that,a 10MHz OHL analog "cheapy" can display a useable signal at around 27MHz!

By & large,DSOs cannot.

[zorthgo]

Thanks for the advice Dread! I was planing on getting the battery so I could lug it around with me. (just in case I need it)   

[tlu]

Zorthgo, how much did you get the scope for?

[zorthgo]

$600 from www.saelig.com.