How often do you use an oscilloscope? Analog? Or digital? Or both?

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moamps

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This method is interesting but has two major drawbacks, IMO. It is not easy to correctly interpret type of the distortion of a square signal, and its magnitude, probably only a few experienced professionals here know this. Another drawback is that often possible overload artifacts cannot be separated from the consequences of linear distortions.

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Newmarket

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This method is interesting but has two major drawbacks, IMO. It is not easy to correctly interpret type of the distortion of a square signal, and its magnitude, probably only a few experienced professionals here know this. Another drawback is that often possible overload artifacts cannot be separated from the consequences of linear distortions.

View attachment 94324


True. But it still offers an opportunity for quick diagnostic work to see (literally) whether there might be a problem.
There's a fair bit to understand to make best use of a 'scope. Considering input signal amplitude and impedance / probe type / range / scale / offset etc.
And more with digital eg sample rate / resolution / memory depth.
Given all that I'd advise the OP and anyone else to get one, or at least get to use one often at university or wherever, now. Rather than waiting until you need to use one to do what you're doing.
 

Rob Flinn

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This method is interesting but has two major drawbacks, IMO. It is not easy to correctly interpret type of the distortion of a square signal, and its magnitude, probably only a few experienced professionals here know this. Another drawback is that often possible overload artifacts cannot be separated from the consequences of linear distortions.

View attachment 94324

Agree, but surely it's quite easy to see if the UIT is overloading by switching the sig gen to a sine wave for a moment.
 

cyrano

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I no longer do repairs myself. Old age, bad eyes and smd etc. The new tech I found is fantastic, has all the gear to handle smd, bga etc, but doesn't use a scope. He's got several logic analysers, tho...
 

JohnRoberts

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Square wave test is fast go/no go test for multi channel consoles. At a glance you can find outliers.

Kind of like reading mechanical VU meters it is an acquired skill that many will never need to learn. ;)

JR
 

AnalogPackrat

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I'm suspicious of people who use phillips head screws when a slot/flathead type is perfectly adequate. This short message was posted by 110baud modem, because that was all that was required.
 

Newmarket

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I'm suspicious of people who use phillips head screws when a slot/flathead type is perfectly adequate. This short message was posted by 110baud modem, because that was all that was required.

I know ! (People familiar with UK politics may want to "read" that in a Liz Truss voice :) )
Don't get me started on PoziDrive / Supadrive and their unnecessary torque enhancing properties...
 

blakeyboy

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Anyone who claims to be a tech and only uses a scope once in 14 years isn't a tech.
Sorry, but true.

No, I'm not sorry.
Until you have learnt all that square wave responses will show you on a scope, until you have learned to spot tiny RF bursts etc, all things that tell you where the problems are, you are failing your customers and don't even know.

All my test benches have the output of any unit going to four devices at once- a scope, a dB meter, a spectrum analyser, and an amp/speaker. I am getting all the info I need at once. ( the spectrum analyser and dB meter obviously going to 100kHz- above 20kHz is where you need to concentrate- amateurs do 20Hz - 20kHz )

I've had enough over the years of 'techs' who do a course somehere in electronics, buy an expensive analyser,
and then try to sort gear out and do it badly. The world is full of them.

Use a scope. Always. Have it permanently connected. It will show up things you would _never_have noticed otherwise, and if you don't use one, you will have returned 'repaired' or 'serviced' or 'restored' gear that is still faulty, and you won't even know.

But your customers will....
 

moamps

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I am _very_ suspicious of someone claiming to be a tech who doesn't use a scope.

I admit my guilt.
From time to time I connect two sine wave signal generators (out of sync of course) to the scope and watch in love the Lissajous curves, the green beauties. Passers-by who break into the office think I’m doing something super smart.:cool:
 

Jen

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I can't imagine designing or servicing audio electronics without a scope; it would be like trying to develop a new recipe while not being able to taste or smell.

My beloved Tek 465 was stolen and I never replaced it, but my trusty old BK Precision backup took up the slack for a few years. It then sat idle for around 10 years, and the electrolytic caps need replaced. The old thing just isn't worth what recapping would cost, not to mention the hours of labor, so I've started looking at both tablet scopes and digital interface scopes.

The PicoScope 2204A for $165 USD especially caught my eye. Can anyone here recommend or not recommend these?
Look for Tektronix 2247A on ebay.
It has cursers and lots of extra that a basic scope does not. Originally over $10,000, now in the $350 to $450 range. I have multiple 7000 series Tek scopes, and Siglent DSO in the lab... and its the 2247A that gets used every day. Bought it new back in the day.
 

doulos35

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"I've had enough over the years of 'techs' who do a course somewhere in electronics, buy an expensive analyzer,
and then try to sort gear out and do it badly. The world is full of them."

I'm sorry, but I disagree with most of what you said. You don't need an expensive analyzer and rarely do you need a scope for things that are 20hz to 20khz if you are not designing the circuit. If you are modding a simple design with high bandwidth opamps like say Jim Williams etc. sure you need a scope cause your modifications aren't compatible with the existing circuits, but needing a scope to sort simple opamp circuits not really. You can get by with signal injection a DMM etc. I have 3 scopes I've designed and built plenty of hardware. The only time I use a scope is for biasing circuits when I need to see what the waveform is doing like distortion "fet biasing" and filters etc." otherwise it's not really needed.
 

Newmarket

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"I've had enough over the years of 'techs' who do a course somewhere in electronics, buy an expensive analyzer,
and then try to sort gear out and do it badly. The world is full of them."

I'm sorry, but I disagree with most of what you said. You don't need an expensive analyzer and rarely do you need a scope for things that are 20hz to 20khz if you are not designing the circuit. If you are modding a simple design with high bandwidth opamps like say Jim Williams etc. sure you need a scope cause your modifications aren't compatible with the existing circuits, but needing a scope to sort simple opamp circuits not really. You can get by with signal injection a DMM etc. I have 3 scopes I've designed and built plenty of hardware. The only time I use a scope is for biasing circuits when I need to see what the waveform is doing like distortion "fet biasing" and filters etc." otherwise it's not really needed.

Missing the point tbh. You may not absolutely need a scope. But if you have one to use it will likely help you to do the work more efficiently / quickly and with greater confidence. In this context there is no such thing as "TMI".
It's just a basic tool tbh.
Of course, you can go further and advocate for specialist audio kit - Audio Precision / Prism / Lindos et al, but that kit is beyond the justifiable reach of many here including myself.

tbh in any other field of electronics this wouldn't even be a contested question. And there are no 'special rules' for audio (is low frequency ac) electronics
 

lightningbefore

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For people who are just entering this area, and intend to stay, I would recommend purchasing a slightly better and more expensive digital oscilloscope like the Keysight EDUX1052G that also has a good signal generator.
Damn, thank you! I had never heard of this one, but it seems like the Keysight EDUX1052G is both analog and digital and has a signal generator all in one?

I may try to save up for that, I much prefer getting started with a one and done type thing until I know more about what all I need - and space is at a premium for me.
 

sodderboy

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I'm late to the party, but I carry a $100 ebay USB o'scope with me to all jobs. It's the size of a thin pack of Marlboros. One probe with alligator clip extenders. If I fry it in a tube amp or something I'll get another one. I use it less than 1 out of 10 service calls, because I can sniff a rat pretty good with my Fluke 8060A. You can see the noise in the numbers.
I'm doing much less bench work so the Tektronix CRT scope has been dark for a while. The bench has brooches and cabachons that I glued for my wife.
Mike
 

ccaudle

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it seems like the Keysight EDUX1052G is both analog and digital

Don't get confused by their use of the term "analog" channels. That doesn't mean it is an analog 'scope in the sense of the old CRT display Tek and HP scopes, that is just to distinguish that it has two analog input channels (which are then digitized, making it a digital scope), compared to the logic level input channels on their models which have a combination of o'scope and logic analyzer function.
Usually in the context of discussing 'scopes the term analog means that the input voltage is conditioned and used to drive the CRT beam deflection directly, no A/D conversion or memory buffering involved, which is definitely not what those Keysight scopes do.
 

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