Tag Archives: Antenna

Pumping Up An Antenna From A Stream Of Sea Water

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Our Hackaday readership represent a huge breadth of engineering experience and knowledge, and we get a lot significant number of our story tips from you. For instance, today we are indebted to [sonofthunderboanerges] for delivering us a tip in the comment stream of one of our posts, detailing an antenna created by coupling RF into a jet of sea water created with a pump (YouTube link). It’s a few years old so we’re presenting it as an object of interest rather than as a news story, but it remains a no less fascinating project for that.

The antenna relies on …read more

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The Poynting Vector Antenna

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Radio amateurs are inventive people, and though not all of them choose to follow it there is a healthy culture of buildng radio equipment among them. In particular the field of antennas is where you’ll find a lot of their work, because the barrier to entry can be as low as the cost of a reel of wire.

Over the years a number of innovative antenna designs have come from radio amateurs’ experimentation, and it’s one of the more recent we’d like to share with you today following a [Southgate ARC] story about a book describing its theory (Here’s an …read more

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Toshiro Kodera: Electromagnetic Gyrotropes

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We’ve learned a lot by watching the talks from the Hackaday Superconferences. Still, it’s a rare occurrence to learn something totally new. Microwave engineer, professor, and mad hacker [Toshiro Kodera] gave a talk on some current research that he’s doing: replacing natural magnetic gyrotropic material with engineered metamaterials in order to make two-way beam steering antennas and more.

If you already fully understood that last sentence, you may not learn as much from [Toshiro]’s talk as we did. If you’re at all interested in strange radio-frequency phenomena, neat material properties, or are just curious, don your physics wizard’s hat and …read more

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RainCube Spreads Its Umbrella

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There are times when a mechanism comes to your attention that you have to watch time and time again, to study its intricacies and marvel at the skill of its designer. Sometimes it can be a complex mechanism such as a musical automaton or a mechanical loom, but other times it can be a device whose apparent simplicity hides its underlying cleverness. Such a moment came for us today, and it’s one we have to share with you.

RainCube is a satellite, as its name suggests in the CubeSat form factor and carrying radar instruments to study Earthly precipitation. One …read more

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Start Your Path to Becoming an Antenna Guru

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We’ve known a few people over the years that have some secret insight into antennas. To most of us, though, it is somewhat of a black art (which explains all the quasi-science antennas made out of improbable elements you can find on the web). There was a time when only the hams and the RF nerds cared about antennas, but these days wireless is everywhere: cell phones, WiFi, Bluetooth, and even RF remote controls all live and die based on their antennas.

You can find a lot of high-powered math discussions about antennas full of Maxwell’s equations, spherical integration and …read more

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Glow-In-The-Dark Antenna Helps You Spot Your Car At Night

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It’s late, and you’re lost in a sea of cars trying to remember where you parked. If only your vehicle had a glow-in-the-dark antenna to make it easier to find, you wouldn’t be in this situation. Faced with just such a problem himself, Instructables user [botzendesign] has put together a handy tutorial to do just that.

[botzendesign] first removed the antenna and lightly abraded it to help the three coats adhesion promoter do its job. A white base coat of vehicle primer was applied — lightly, so it doesn’t crack over time — and once it had set, three coats …read more

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Pneumatic Launcher Gets Ham Antennas Hanging High

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Amateur radio is an eclectic hobby, to say the least. RF propagation, electrical engineering, antenna theory – those are the basics for the Ham skillset. But pneumatics? Even that could come in handy for hanging up antennas, which is what this compressed-air cannon is designed to do.

[KA8VIT]’s build will be familiar to any air cannon aficionado. Built from 2″ Schedule 40 PVC, the reservoir is connected to the short barrel by a quarter-turn ball valve. Charging is accomplished through a Schrader valve with a cheap little tire inflator, and the projectile is a tennis ball weighted with a handful …read more

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Would You Like a Satellite Dish?

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Satellite dishes are a common site these days, although admittedly most of them are Ku- and Ka-band dishes. The older C-band dishes are still around, though, just less frequently in people’s yards. [Greenish Apple] decide to cut the cable and start watching free TV so he built a C-band dish. The trick is, he made the dish out of wood.

The design is the offset type, not a prime focus dish–that is, the electronics are not in the center of the dish but on the side. Wood isn’t particularly good at reflecting RF, of course, so over the wooden skeleton, …read more

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Ham Antenna Rises to the Occasion

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There was a time when you could do what you wanted in your yard and hams could build giant antenna farms. These days, there are usually laws or deed restrictions that stop that from happening. Even if you can build an antenna, you might want to quickly put up something temporary in an emergency.

[Eric’s] solution? Suspend a wire from a weather balloon filled with helium from the local WalMart. The 8 foot balloon took two containers (18 cubic feet) of gas before it would rise sufficiently. Once you have a floating balloon, the rest of the concept is simple: …read more

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Get Set For SAQ On Alexanderson Day With These Active Antennas

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If you need to generate a radio frequency electrical signal, you will make some form of electronic oscillator. We’ll probably all be used to oscillators using transistors, tubes, logic gates or a host of other electronic technologies. Similarly if you need to generate radio frequencies at high powers, you’ll couple your oscillator to an amplifier, a relatively simple task with today’s electronic parts bin.

If you needed to do the same thing with a high power radio signal in the early years of the 20th century, none of these options were open to you. There were no transistors or integrated …read more

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