Ancient Cable Modem Reveals Its RF Secrets

Most reverse engineering projects we see around here have some sort of practical endpoint in mind. Usually, but not always. Reverse-engineering a 40-year-old cable modem probably serves no practica…

How Much Bandwidth Does CW Really Occupy?

Amateur radio license exams typically have a question about the bandwidths taken up by various modulation types. The concept behind the question is pretty obvious — as guardians of the spectr…

Proper Routing Makes For Many Happy Return Paths

Here’s a question for you: when your PCB has a ground plane layer, where do return signals flow? It seems like a trick question, but as [Kristof Mulier] explains, there’s more to return…

The Perils Of Return Path Gaps

The radio frequency world is full of mysteries, some of which seem to take a lifetime to master. And even then, it seems like there’s always something more to learn, and some new subtlety tha…

A Look Inside A 70-GHz Electromechanical Attenuator

It might not count as “DC to daylight,” but an electromechanical attenuator that covers up to 70 GHz is pretty close, and getting a guided tour of its insides is quite a treat. Perhaps …

CloseUpRussia (@closeuprussia@mastodon.social)

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CloseUpRussia (@closeuprussia@mastodon.social)

1.02K Posts, 146 Following, 697 Followers · Visualizing Russia We do not pretend to the truth, but only show the Russian reality as it is seen by our authors.

CloseUpRussia (@closeuprussia@mastodon.social)

1.02K Posts, 146 Following, 696 Followers · Visualizing Russia We do not pretend to the truth, but only show the Russian reality as it is seen by our authors.

CloseUpRussia (@closeuprussia@mastodon.social)

1.01K Posts, 146 Following, 689 Followers · Visualizing Russia We do not pretend to the truth, but only show the Russian reality as it is seen by our authors.

CloseUpRussia (@closeuprussia@mastodon.social)

1.01K Posts, 144 Following, 686 Followers · Visualizing Russia We do not pretend to the truth, but only show the Russian reality as it is seen by our authors.

CloseUpRussia (@closeuprussia@mastodon.social)

995 Posts, 144 Following, 681 Followers · Visualizing Russia We do not pretend to the truth, but only show the Russian reality as it is seen by our authors.

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993 Posts, 144 Following, 678 Followers · Visualizing Russia We do not pretend to the truth, but only show the Russian reality as it is seen by our authors.

SMA Connector Footprint Design For Open Source RF Projects

When you first start out in the PCB layout game and know just enough to be dangerous, you simply plop down a connector, run a trace or two, and call it a hack. As you learn more about the finer poi…

Don’t Let The Baluns Float Over Your Head

Most ham radio operators will build an antenna of some sort when they first start listening or transmitting, whether it’s a simple dipole, a beam antenna like a Yagi, or even just a random wi…

Low-Cost RF Power Sensor Gets All The Details Right

Dirty little secret time: although amateur radio operators talk a good game about relishing the technical challenge of building their own radio equipment, what’s really behind all the DIY gea…

JFET Stands In For Triode In This Infinite Impedance Detector

An “Infinite Impedance Detector” might sound a little like something that [Zaphod Beeblebrox] would use to zip around the galaxy. It’s not, of course, but it is an interesting and…

RF Spectrometer Sees Inside

Spectrometry is a well-known technique or, more correctly, a set of techniques. We usually think of it as the analysis of light to determine what chemicals are producing it. For example, you can te…

Q Meter Measures… Q, Of Course

If you’ve ever dealt with RF circuits, you probably have run into Q — a dimensionless number that indicates the ratio of reactance to resistance. If you ever wanted to measure Q, you co…