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

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swpaskett

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Ooh, forgot to mention: Salaea is a reputable company with a weird name that has been around 20 years or so. I have ordered a couple items in the distant past. They have some interesting products of European origin. A lot of it seems priced rather on the high end of what I think it is worth, but if you are looking for something unusual you might just find it there.
 

Analog_Fan

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@Analog_Fan , If you are used to a 465 or even BK I think you will be disappointed by what Pico offers. I considered them some time ago but was disappointed in the feature/cost ratio. Eventually I settled on a BK Precision scope, a decent analog 2 channel 100MHz dual trigger scope for about half what the Pico costs now. Patiently shopping Ebay eventually pays off. It's not Tek, but still a very good scope for the price.
I recommend analog scopes for anyone who has never used a scope before. They are more intuitive, often show artifacts that disappear in the snow on digital scopes, and all the controls are in your face, not hidden under the fourth layer of some menu somewhere.
i use a Tektronix 2212 digital storage scope, i got it second hand with manual, quite not really suitable for analyzing logic, like SPI, MIDI, I2C, you can see it, but not really decode it on full speed, but you can measure frequencies, hold the scan an zoom in and some more tricks. not bad for a device made pre 2000.
I also got a Philipsfluke 3110 from the 70'ties, i recapped the high voltage ceramics, but not the electrolythic, the machine is to complicated to take apart to reach them, to many wires you got to label, de solder and re solder.

Would always opt for Tektronix, Agilent, Rohde & Schwarz ... now they also include logic analizers, so you can scan up to 16 channels at the same time, spectrum analyzers, SPI, I2C, USB, but you gotta pay extra for that. if you're also in for mcu's.

Ebay Tektronix TDS series are not expensive on ebay, i see.
starting from 60us$

Tektronix TDS 224 Four Channel Digital Real-Time Oscilloscope 100 MHz 1 GS/s

Tektronix TDS 224 Four Channel Digital Real-Time Oscilloscope 100 MHz 1 GS/​

299us$
 

Khron

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Nice, thank you for the tip! I’m in Austin, TX - but have no idea where to go to look. We have the university here, and I have a community college pass (for my audio electronics course, haha) and some great synth stores…but that’s all that comes to mind.
Craigslist? Or other private commerce sites?

I live in Finland, and a bunch of years back i recall scoring a Tek 2225 and a 2230, sold as faulty, for 100e total. The 2230 needed a power supply recap & slight repair, but the 2225 was in fact fine, and is still my default scope to this day (fanless, to boot). Haven't had much motivation yet to dig into the digital storage side of the 2230 though...
 

nielsk

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Look on Craigslist & marketplace, Freecycle if you have it there.
With a little patience you can find a working (check it out before you buy it, they have a test output on the front panel) analog scope for around $25
I think the simplicity, response, and weight (no pulling it off the bench accidentally!) argue in favor of an analog scope to begin with. For most analog signal troubleshooting you do not need any of the features a digital offers that an analog does not.
 

Analog_Fan

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(no pulling it off the bench accidentally!)
Yeah, that's a real danger with the lead of the probe as it hangs "next" to the table you work on and suddenly you have to get up to search for a ic, transitor or whatever part and step in the loop of the lead and while you step ...
 

JohnRoberts

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In a case of do what I say not what I did, I stand by my advice to look for an inexpensive used scope (analog or digital). We've enjoyed drastic price compression for all kinds of bench test equipment. IMO it would be useful to first learn how scopes work hands on, to better assess features for a new purchase.

The first scope I bought with my own money (usually my employers provided the scope) was a kit from Heathkit. IIRC it was around $450 back in 70s dollars, a fraction of the price for a real commercial scope. That old Heathkit worked serviceably for decades. This century when it was too tired to work properly I replaced it with a decent new generation Tektronix digital (TDS1002).

For TMI about working with old scopes, in cold weather technicians would nestle between two scopes on their rolling carts to enjoy the warmth they would throw off from all the tubes inside.

JR
 

Disco Volante

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I once found three Tek scopes behind a barn in, yes, Austin Texas. One of them was still serviceable and picked up nicely after a good clean and recap... I also own a old Tek tube-scope, rescued from the recycling center in working condition. It's nestling on a shelf waiting for recap day...

Happy tinkering!
 
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I love using a "real" 'scope - they are in my opinion nicer to use and better pieces of equipment than anything digital or PC based .... BUT ... nowadays I rely on a Picoscope because they're just so convenient and don't take up too much space.
 

Analog_Fan

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I love using a "real" 'scope - they are in my opinion nicer to use and better pieces of equipment than anything digital or PC based .... BUT ... nowadays I rely on a Picoscope because they're just so convenient and don't take up too much space.
lol, yeah, the scope is to get away from the computer or whatever.
: )
 

majenko

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My scope sees daily usage (though alas mainly for digital work). When I do use it for analogue it's most often on vintage kit I'm repairing, and then it's usually coupled with my AWG to inject signals into significant points in a circuit and test the different stages in an amp.

Mind you, some times I actually find it better to use a speaker (sometimes with a small power amp, but *always* with a DC bias blocking capacitor) for inspecting the injected signal - it can be much easier to *hear* the noise from a faulty germanium tranny than see it on the scope.
 

Bo Deadly

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This is from a few years back, but i would argue it still rings quite true:
I'm not so sure about that. First of all, I have the DS1052E and it's a POS compared to the digital scopes you can get today. The analog scopes are just so limited. And I would not be surprised at all if one of the little USB ones are pretty good these days (that video is 12 years old). I've never had one but I have a pretty good idea about what parts are required to make a decent scope and I don't see why one couldn't be made pretty small. The real value is actually in the software. So it makes a lot of sense to just have the software running on a computer (along side your audio spectrum analyzer software). If I were to buy a new scope, I would definitely look at the little USB ones. I would just look very carefully at the sort of rates, resolution, software and so on. If they just don't compare on paper, I would get a newer DS scope (preferrably 10 bit or maybe even 12 bit if I'm feeling flush). There's no way I would buy an analog scope. Ever. I don't care how much you're trying to save. I'm not sure I would take one even if it were given to me for free and I had an unlimited about of bench space.
 

Rob Flinn

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I use a cheap digital scope which I bought when the last of my donated analog scopes died. I appreciate that the trace looks a bit better on an analog scope, but most of the work I do I just need to see that a sine wave is making it through ok & I don't really care whether it's analog or digital. I also have a velleman HPS10 whcih I bought 16 or so years ago specifically for when I was doing a desk service overseas & couldn't take too much kit on the flight. Worked a charm & did all I needed to get the desk going.

For me this digital/analog scope argument is a bit like when someone asks for a DMM recommendation & people start saying they have to get a fluke or or the meter is not worth having. For most people having a really expensive meter is not going to help them do a better job. I have owned expensive and cheap meters, & they all have flaked out eventually. I have a bench meter that is really accurate but I got in a EOL sale for £50, but the rest of the time I use a £15 multicomp DMM. Guess what I have never found it a limitation & when it eventually dies I won't have lost a pile of cash.
 

JohnRoberts

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The first scope to get started needs to be cheap, not analog or digital. After you learn how to use one then you can start thinking about features.

+1 Don't just trust the scope image, listen to the path also with headphones or low power amp/speaker...

some circuits sound good while looking bad, and vice versa...

JR
 

Matador

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I've moved away from looking at scope plots to using a signal generator, injected through a large 1uF/1000V coupling cap, so I can touch it to various points in the circuit, then monitor the circuit live - like if it's a guitar amp, listen through the speaker, for a mike preamp, connect it through monitors, etc. I can quickly locate problem spots that way rather than taking scope images, which don't always reveal subtle distortions, etc.
 

Analog_Fan

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I'm not so sure about that. First of all, I have the DS1052E and it's a POS compared to the digital scopes you can get today. The analog scopes are just so limited. And I would not be surprised at all if one of the little USB ones are pretty good these days (that video is 12 years old). I've never had one but I have a pretty good idea about what parts are required to make a decent scope and I don't see why one couldn't be made pretty small. The real value is actually in the software. So it makes a lot of sense to just have the software running on a computer (along side your audio spectrum analyzer software). If I were to buy a new scope, I would definitely look at the little USB ones. I would just look very carefully at the sort of rates, resolution, software and so on. If they just don't compare on paper, I would get a newer DS scope (preferrably 10 bit or maybe even 12 bit if I'm feeling flush). There's no way I would buy an analog scope. Ever. I don't care how much you're trying to save. I'm not sure I would take one even if it were given to me for free and I had an unlimited about of bench space.
wel, pretty sure you can make a Scope with an Arduino/Teensy and a oled screen.
But you would need to use 0.1% resistors offset a opamp with 50% of 3v33 from the Arduino, AC/DC coupling and what not.

Rigol is some sort of Chinese knock of thing, €367.77 new

A pre 2000 Tektronix 2212 is digital and you can get one of these for like 100us$ used.
accept it can't store a image to a USB stick, but you can connect a certain printer to it.

1652992375130.png
1652992502318.png

You're better off buying the real deal.
 

Rob Flinn

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I've moved away from looking at scope plots to using a signal generator, injected through a large 1uF/1000V coupling cap, so I can touch it to various points in the circuit, then monitor the circuit live - like if it's a guitar amp, listen through the speaker, for a mike preamp, connect it through monitors, etc. I can quickly locate problem spots that way rather than taking scope images, which don't always reveal subtle distortions, etc.
I understand your method, but it probably wouldn't tell you if the circuit is hooting at 200Khz, which a scope would.
 

JohnRoberts

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I've moved away from looking at scope plots to using a signal generator, injected through a large 1uF/1000V coupling cap, so I can touch it to various points in the circuit, then monitor the circuit live - like if it's a guitar amp, listen through the speaker, for a mike preamp, connect it through monitors, etc. I can quickly locate problem spots that way rather than taking scope images, which don't always reveal subtle distortions, etc.
That can be an effective troubleshooting technique used properly.

IIRC I used a smaller cap ( more like a 0.1uF mylar) with a modest R in series (1-2k ohm). If you cap couple right into a VE bus without the R you could generate a large signal (even with the R in some cases).

The first rule of troubleshooting is don't break something else.

A scope is just one window into what the SKU circuit is doing, listening to the circuit output is another. Use all the tools in your kit.

JR
 

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