Network Analysers: The Electrical Kind

Instrumentation has progressed by leaps and bounds in the last few years, however, the fundamental analysis techniques that are the foundation of modern-day equipment remain the same. A network analyzer is an instrument that allows us to characterize RF networks such as filters, mixers, antennas and even new materials for microwave electronics such as ceramic capacitors and resonators in the gigahertz range. In this write-up, I discuss network analyzers in brief and how the DIY movement has helped bring down the cost of such devices. I will also share some existing projects that may help you build your own along …read more

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Hackaday Links: September 3, 2017

The TI-83, TI-84, and TI-86 have been the standard graphing calculators in classrooms for two decades. This is the subject of an xkcd. Now, hopefully, there’s a contender for the throne. Numworks is a graphing calculator that looks like it was designed in at least 2006 (so very modern), and apparently, there’s a huge community behind it.

Juicero is shutting down. No one could have seen this one coming. The Juicero was a $700 press that turned proprietary, DRM’ed juice packs into juice and garbage. It was exquisitely engineered, but it turns out very few people want to spend thousands …read more

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Measuring Capacitors at the Birth of Rock and Roll

The late 1950s [Bill Haley], [Elvis Presley], and [Little Richard] were building a new kind of music. Meanwhile, electronic hobbyists were building their own gear from Heathkit. A lot of that gear shows you how far we’ve come in less than a century. [Jeff Tranter’s] YouTube channel is a great way to look at a lot of old Heathkit gear, including this really interesting “direct reading capacity meter.” You can see the video, below.

Measuring capacitance these days is easy. Many digital multimeters have that function. However, those didn’t exist in the 1950s–at least, not in the way we know …read more

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Review: The O-scope Mayer D4/WG5 Calibrated Fleshy Test Probe

It’s not often that we are shown an entirely new class of test equipment here at Hackaday, so it was with some surprise that we recently received the new O-scope Mayer offering. If your most simple piece of test equipment is your own finger, able to measure temperature, detect voltage, and inject a 50 or 60 Hz sine wave, then what they have done is produce a synthetic analogue with a calibrated reading. The idea is that where previously you could only say “Too hot!”, or “High voltage!”, you should now be able to use their calibrated probe to gain …read more

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Review: Digilent Analog Discovery 2

I recently opened the mailbox to find a little device about the size of White Castle burger. It was an “Analog Discovery 2” from Digilent. It is hard to categorize exactly what it is. On the face of it, it is a USB scope and logic analyzer. But it is also a waveform generator, a DC power supply, a pattern generator, and a network analyzer.

I’ve looked at devices like this before. Some are better than others, but usually all the pieces don’t work well at the same time. That is, you can use the scope or you can use …read more

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Ask Hackaday: Help Me Choose A ‘Scope

If there is one instrument that makes an electronic engineer’s bench, it is the oscilloscope. The ability to track voltages in the time domain and measure their period and amplitude is one akin to a light in the darkness, it turns a mere tinkerer with circuits into one in command of them. Straightforward add-on circuits can transform a basic oscilloscope into a curve tracer, frequency response display, and much more, and modern oscilloscopes offer a dizzying array of useful measurement features unimaginable to engineers only a few years ago. And I need your help to pick a new one.

The

…read more

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Tools of the Trade – Test and Programming

In our final installment of Tools of the Trade (with respect to circuit board assembly), we’ll look at how the circuit board is tested and programmed. At this point in the process, the board has been fully assembled with both through hole and surface mount components, and it needs to be verified before shipping or putting it inside an enclosure. We may have already handled some of the verification step in an earlier episode on inspection of the board, but this step is testing the final PCB. Depending on scale, budget, and complexity, there are all kinds of ways to …read more

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Tools of the Trade – Inspection

In the last episode, we put our circuit boards through the reflow process. Unfortunately, it’s not 100% accurate, and there are often problems that can occur that need to be detected and fixed. That’s what the inspection step is for. One could insert an inspection step after paste, after placement, and after reflow, but the first two are icing on the cake — the phase where most mistakes can be caught is after reflow.

There are a number of problems typical with a surface mount reflow process:

  • Tombstoning – This is when a component stands up vertically. This is bad

…read more

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Sciencing DVD-RW Laser Diodes

If you’ve played around with laser diodes that you’ve scavenged from old equipment, you know that it can be a hit-or-miss proposition. (And if you haven’t, what are you waiting for?) Besides the real risk of killing the diode on extraction by either overheating it or zapping it with static electricity, there’s always the question of how much current to put into the thing.

[DeepSOIC] decided to answer the latter question — with science! — for a DVD-burner laser that he’s got. His apparatus is both low-tech and absolutely brilliant, and it looks like he’s getting good data. So let’s …read more

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Poor Man’s Time Domain Reflectometer

A time domain reflectometer, or TDR, is an essential piece of test gear when working on long cables. The idea is simple: send a pulse down the cable and listen for the reflection from the far end. The catch is that pesky universal constant, the speed of light.

The reason the speed of light is an issue is that, in a traditional system, the pulse needs to be complete before the reflection. Also, time is resolution, so a 1 GHz sampling rate provides a resolution of about 10 centimeters. [Krampmeier] has a different design. He sends variable length pulses and …read more

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