Recommendations for an oscilloscope?

Apologies if this is slightly off-topic for the subforum, but what oscilloscopes are people using for repair / modding work, and what would be a good recommendation for a relatively affordable one that would still be useful?

I ask in this forum because it seems like an oscilloscope ends up being useful for a large number of tasks, especially calibrations and testing video outputs.

There are quite a few USB-based digital oscilloscopes available that are very inexpensive, but it is unclear to me whether these are any good. I'd be quite willing to go with an older analog scope, though. Probably the highest-frequency signals that I would expect to be looking at are 480-line NTSC, so I would assume that a scope capable of sub 10MHz would be sufficient.

Thanks for any suggestions!

 

How many channels do you need and what is your budget? Some older analog scopes (especially older Tektronix) are fantastic. On the flipside, they lack features that only digital scopes have such as sampling, different triggering options, calculations done for you on the scope for some more basic things. But, they are solid pieces of equipment that will do you well. I just bought my first scope as a happy birthday to me type gift a few weeks ago (first digital for me as well since we used older Tektronix analog ones in college).

I can tell you that I was gonna get a Rigol DS1052e, but the site I got it from had a cyber monday sale on the DS1054z (4 channel version) so I got that instead. It seems that the sample rate in these is actually locked by software and the hardware is the same as the 1152 and 1154 so you can actually hack the scope and turn it into the next model up without the $400 upcharge. I was planning to do an "I got a scope" thread, but have been busy so I haven't used it much except using the built in square wave generator to test it out.

 

I have a DS1052, I want the DS1054z now though

 

I never looked into Rigol scopes, but this DS1054z seems like a really decent scope for $400 USD. Damn...the quest for better tools never ceases.

 

It is, and it can be converted into an 1154 for free. So really you are almost getting an 8 or 900 dollar scope for $400. I found mine for $329 on sale with free shipping. While there are definitely better brands such as Tektronix and Agilent, Rigol actually makes a pretty good product and the general consensus is that they are quite a ways ahead of the bottom of the barrel shit such as Owon. IMO, and I am no scopemaster, the best bang for the buck on the market if 2 channel is enough for you is a DS1052E.

In his first video, Dave from EEVBlog reviewed the 1052E at about 7:10



In a later one he reviews the 1054z



He also has videos where he takes them apart, does tests on them, and does the upgrades I mentioned above.

 

Seconding the Rigol DS1054Z.
Fantastic scope for the price and the "free" upgrade (You're not supposed to be able to do it, but all Rigol scopes have the same flaw that allows it to be done, so one would assume they don't care) make it the best bang for buck you'll have below 500$.

The DS1052E is a bit cheaper, but is outdated as all hell. The DS1054Z is actually the model that replaced it.

As an aside, Dave's videos are some of my favorite things to watch on YouTube. Really informative and I learned a lot about electronics from him

 

Its hardly "outdated as all hell", its not like measuring signals changes much. But yes, for the extra money you might as well get the newer model (which didnt exist when I got mine).

 

Well, it's mostly for comfort.
Measuring signals doesn't change much, but the new model has a quicker interface, higher screen resolution and a nice "analog-like" display for the waveform (Brighter where the waveform repeats and dimmer where it's less frequent).

It essentially does the same thing, but is a bit more pleasing to use, imho.

 

I am using the Rigol DS1074Z, and I really like it. Wouldn't mind an old, analog one! However, my bench space is rather small & the modern scopes really help with that.

 

Is there a 2 channel version that replaced it? I ask because I doubt the 1054z is the upgraded replacement for the 1052E based on the extra channels alone.

I hear that. I have mine on my office desk and it's like a small boombox size-wise. Really convenient. Nice size screen for a unit this size too.

 

This is all extremely helpful, thanks! I'm impressed with how affordable the Rigol scopes are. I had been looking at analog Tektronix scopes on eBay, and a Tektronix 465 is around $180 or so. It seems like the far better option to go with a brand new Rigol DS1054Z for $399, if only because I know it will arrive working. (The EEVBlog review is great, by the way!)

 

Glad we could help. Happy modding

 

I use older Tektronix scope. I got it in a trade deal long ago (along with bench power supply, frequency generator, and couple other stuff) and it worked pretty well for my need. Since it's older analog scope, it isn't constrained by display resolution like digital scope but it does not have the ability to freeze the waveform so I can't catch a glitch that only occurs on specific event or triggered.

20MHz dual trace is pretty useful for wide variety of jobs.

 

Hi Wilykat, thanks for the recommendation; I agree that 20MHz is probably enough for any of the ancien... er... "retro" electronics that I'm planning to look at. What Tektronix scope do you use, or would you recommend? (As I mentioned above, I've seen the Tektronix 465 available for around $180, and I'm considering just going with the $330-400 for a new Rigol.)

Thanks again.

 

The Rigol is a nice beginner's scope if you can afford it. If not, you should be able to get a 20-50MHz scope for under $100 on eBay, Craigslist or an electronics / radio enthusiast's forum (or local swap meet). Sometimes free.

As for 10MHz scopes, they're pretty limited. Remembering you should buy a scope with a bandwidth five times higher than the maximum signal you want to measure, it's really only recommended for up to 2MHz. Fine for audio, or just learning the ropes.

 

Hi retro, thanks for the advice; I didn't realize that. What's the reason for the five times guideline? I was originally thinking two times (i.e. the Nyquist rate). Is the five times to avoid aliasing from with higher-frequency noise that happens to get into the signal?

 

Accuracy. The scope has to capture the fundamental, third and fifth harmonics. More than that, and your amplitude accuracy is going to be greater than 2%. Your probe also has an effect on that, too. Old analogue scopes used to go on a three times rule, but for digital, at least five.

If you're capturing pulses instead of sine waves, you may need even more than five times bandwidth... although you'd probably be going on rise times in that instance, not bandwidth.