oscilloscope

281 Articles

Amazing Oscilloscope Demo Scores The Win At Revision 2025

April 26, 2025 by 5 Comments

Classic demos from the demoscene are all about showing off one’s technical prowess, with a common side order of a slick banging soundtrack. That’s precisely what [BUS ERROR Collective] members [DJ_Level_3] and [Marv1994] delivered with their prize-winning Primer demo this week.

This demo is a grand example of so-called “oscilloscope music”—where two channels of audio are used to control an oscilloscope in X-Y mode. The sounds played determine the graphics on the screen, as we’ve explored previously.

The real magic is when you create very cool sounds that also draw very cool graphics on the oscilloscope. The Primer demo achieves this goal perfectly. Indeed, it’s intended as a “primer” on the very artform itself, starting out with some simple waveforms and quickly spiraling into a graphical wonderland of spinning shapes and morphing patterns, all to a sweet electronic soundtrack. It was created with a range of tools, including Osci-Render and apparently Ableton 11, and the recording performed on a gorgeous BK Precision Model 2120 oscilloscope in a nice shade of green.

If you think this demo is fully sick, you’re not alone. It took out first place in the Wild category at the Revision 2025 demo party, as well as the Crowd Favorite award. High praise indeed.

We love a good bit of demoscene magic around these parts.

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Virtual Nodes, Real Waves: A Colpitts Walkthrough

April 22, 2025 by 14 Comments

If you’ve ever fumbled through circuit simulation and ended up with a flatline instead of a sine wave, this video from [saisri] might just be the fix. In this walkthrough she demonstrates simulating a Colpitts oscillator using NI Multisim 14.3 – a deceptively simple analog circuit known for generating stable sine waves. Her video not only shows how to place and wire components, but it demonstrates why precision matters, even in virtual space.

You’ll notice the emphasis on wiring accuracy at multi-node junctions, something many tutorials skim over. [saisri] points out that a single misconnected node in Multisim can cause the circuit to output zilch. She guides viewers step-by-step, starting with component selection via the “Place > Components” dialog, through to running the simulation and interpreting the sine wave output on Channel A. The manual included at the end of the video is a neat bonus, bundling theory, waveform visuals, and circuit diagrams into one handy PDF.

If you’re into precision hacking, retro analogue joy, or just love watching a sine wave bloom onscreen, this is worth your time. You can watch the original video here.

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Low Cost Oscilloscope Gets Low Cost Upgrades

April 20, 2025 by 51 Comments

Entry-level oscilloscopes are a great way to get some low-cost instrumentation on a test bench, whether it’s for a garage lab or a schoolroom. But the cheapest ones are often cheap for a reason, and even though they work well for the price they won’t stand up to more advanced equipment. But missing features don’t have to stay missing forever, as it’s possible to augment them to get some of these features. [Tommy’s] project shows you one way to make a silk purse from a sow’s ear, at least as it relates to oscilloscopes.

Most of the problem with these lower-cost tools is their low precision due to fewer bits of analog-digital conversion. They also tend to be quite noisy, further lowering the quality of the oscilloscope. [Tommy] is focusing his efforts on the DSO138-mini, an oscilloscope with a bandwidth of 100 kHz and an effective resolution of 10 bits. The first step is to add an anti-aliasing filter to the input, which is essentially a low-pass filter that removes high frequency components of the signal, which could cause a problem due to the lower resolution of the device. After that, digital post-processing is done on the output, which removes noise caused by the system’s power supply, among other things, and essentially acts as a second low-pass filter.

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Long-tail pair waves

Current Mirrors Tame Common Mode Noise

March 17, 2025 by 12 Comments

If you’re the sort who finds beauty in symmetry – and I’m not talking about your latest PCB layout – then you’ll appreciate this clever take on the long-tailed pair. [Kevin]’s video on this topic explores boosting common mode rejection by swapping out the old-school tail resistor for a current mirror. Yes, the humble current mirror – long underestimated in DIY analog circles – steps up here, giving his differential amplifier a much-needed backbone.

So why does this matter? Well, in Kevin’s bench tests, this hack more than doubles the common mode rejection, leaping from a decent 35 dB to a noise-crushing 93 dB. That’s not just tweaking for tweaking’s sake; that’s taking a breadboard standard and making it ready for sensitive, low-level signal work. Instead of wrestling with mismatched transistors or praying to the gods of temperature stability, he opts for a practical approach. A couple of matched NPNs, a pair of emitter resistors, and a back-of-the-envelope resistor calculation – and boom, clean differential gain without the common mode muck.

If you want the nitty-gritty details, schematics of the demo circuits are on his project GitHub. Kevin’s explanation is equal parts history lesson and practical engineering, and it’s worth the watch. Keep tinkering, and do share your thoughts on this.

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Repairing An Old Heathkit ‘Scope

February 8, 2025 by 8 Comments

With so many cheap oscilloscopes out there, the market for old units isn’t what it used to be. But if you have a really old scope, like the Heathkit O-10 that [Ken] found in his basement, there is vintage cred to having one. [Ken’s] didn’t work, so a repair session ensued. You can see the results in the video below.

You can tell this is in an old scope — probably from the mid 1950s — because of its round tube with no graticle. Like many period scopes, the test probe input was just 5-way binding posts. The O-10 was the first Heathkit “O-series” scope that used printed circuit boards.

The device looked pretty good inside, except for a few dents. Of course, the box has tubes in it, so every power up test involves waiting for the tubes to warm up. [Ken] was very excited when he finally got a single green dot on the screen. That did, however, require a new CRT.

It wasn’t long after that he was able to put a waveform in and the scope did a good job of reproducing it. The unit would look good in an old movie, but might not be the most practical bench instrument these days.

These Heathkit scopes and their cousins were very popular in their day. The $70 price tag sounds cheap, but in the mid-1950s, that was about a month’s rent in a four-room house. While primitive by today’s standards, scopes had come a long way in 9 or 10 years.

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Your Favorite Basic Oscilloscope Operation Guide?

February 8, 2025 by 9 Comments

Like many pieces of lab equipment, oscilloscopes are both extremely useful and rather intimidating to a fledgling user. Unlike a digital multimeter with its point-and-measure functionality, digital storage oscilloscopes (DSOs) require fundamental knowledge before they can be used properly. Yet at the same time nobody likes reading manuals, so what is one to do? Try the Absolute Beginner’s Guide to DSOs  by [Arthur Pini]

[Pini’s] Cliff’s Notes version of your scope’s manual isn’t half bad. It covers the basic user interface and usage of a (stand-alone) DSO. Unfortunately, it focuses a bit too much on a fancy touch-screen Teledyne LeCroy MSO rather than something the average hobbyist is likely to have lying around.

We rather like the PSA-type videos such as the classic ‘“How not to blow up your oscilloscope” video by [Dave] over at EEVBlog. Many guides and introductions cover “what to do,” but covering common safety issues like improper grounding, isolation, or voltages might be a better place to start.

What tutorial or reference work would you hand to an oscilloscope newbie? We can endorse a hands-on approach with a suitable test board. We also enjoyed [Alan’s] video on the topic. Even if you are an old hand, do you know how to use all those strange trigger modes?

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[Kerry Wong] Talks (and Talks) About A 300 MHz Oscilloscope

December 29, 2024 by 10 Comments

There aren’t many people who could do an hour-long video reviewing an oscilloscope, but [Kerry Wong] is definitely one of them. This time, he’s looking at a UNI-T MSO2304X 300 MHz scope. The review might be a little long, but the scope — like many modern scopes — has a lot of features for measuring power, accommodating digital signals with an add-on pod, and protocol decoding.

The scope has a touchscreen and four normal inputs, plus two frequency generator outputs. You can also use a mouse or an external display. But, of course, what you really want to know is how the scope performs when reading signals.

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