Tag Archives: Radio

RadiantBee Is A Flying Microwave Antenna Calibration System

Posted on by

Many of the projects we link to here at Hackaday have extensive write-ups, pages of all the detail you could need. Sometimes though we happen upon a project with only a terse description to go on, but whose tech makes it one worth stopping for and unpicking the web of information around it.

Such a project is [F4GKR] and [F5OEO]’s RadiantBee, an attempt to use a beacon transmitter on a multirotor as an antenna calibration platform. (For more pictures, see this Twitter feed.) In this case a multirotor has a GPS and a 10 GHz beacon that emits 250 ms …read more

Continue reading RadiantBee Is A Flying Microwave Antenna Calibration System→

Backscatter Your Own FM Pirate Radio Station

Posted on by

If you live in a city, you’re constantly swimming in a thick soup of radio-frequency energy. FM radio stations put out hundreds of kilowatts each into the air. Students at the University of Washington, [Anran Wang] and [Vikram Iyer], asked themselves if they could harness this background radiation to transmit their own FM radio station, if only locally. The answer was an amazing yes.

The trailer video, embedded below, demos a couple of potential applications, but the paper (PDF) has more detail for the interested. Basically, they turn on and off an absorbing antenna at a frequency that’s picked so …read more

Continue reading Backscatter Your Own FM Pirate Radio Station→

Move Over Baofeng, Xiaomi Want To Steal Your Thunder

Posted on by

To a radio amateur who received their licence decades ago there is a slightly surreal nature to today’s handheld radios. A handheld radio should cost a few hundred dollars, or such was the situation until the arrival of very cheap Chinese radios in the last few years.

The $20 Baofeng or similar dual-bander has become a staple of amateur radio. They’re so cheap, you just buy one because you can, you may rarely use it but for $20 it doesn’t matter. Most radio amateurs will have one lying around, and many newly licensed amateurs will make their first contacts on …read more

Continue reading Move Over Baofeng, Xiaomi Want To Steal Your Thunder→

Origin of Wireless Security: the Marconi Radio Hack of 1903

Posted on by

The place is the historic lecture theater of the Royal Institution in London. The date is the 4th of June 1903, and the inventor, Guglielmo Marconi, is about to demonstrate his new wireless system, which he claims can securely send messages over a long distance, without interference by tuning the signal.

The inventor himself was over 300 miles away in Cornwall, preparing to send the messages to his colleague Professor Fleming in the theater. Towards the end of Professor Flemings lecture, the receiver sparks into life, and the morse code printer started printing out one word repeatedly: “Rats”. It then …read more

Continue reading Origin of Wireless Security: the Marconi Radio Hack of 1903→

Universal Radio Hacker

Posted on by

If you are fascinated by stories you read on sites like Hackaday in which people reverse engineer wireless protocols, you may have been tempted to hook up your RTL-SDR stick and have a go for yourself. Unfortunately then you may have encountered the rather steep learning curve that comes with these activities, and been repelled by a world with far more of the 1337 about it than you possess. You give up after an evening spent in command-line dependency hell, and move on to the next thing that catches your eye.

You could then be interested by [Jopohl]’s Universal Radio …read more

Continue reading Universal Radio Hacker→

Radio and Phone Speaker has Style

Posted on by

Building a crystal radio isn’t exactly rocket science. Some people who build them go for pushing them technically as far as they can go. Others, like [Billy Cheung], go for style points. The modular radio and phone speaker looks like it came out of the movie Brazil. The metallic gramophone-like speaker horn adds to the appeal and mechanically amplifies the sound, too.

The video (see below) isn’t exactly a how-to, but if you watch to the end there is enough information that you could probably reproduce something at least similar. There are actually several horns. One is made from copper, …read more

Continue reading Radio and Phone Speaker has Style→

A Real Star Trek Communicator Badge

Posted on by

Star Trek has never let technology get in the way of a good story. Gene Roddenberry and the writers of the show thought up some amazing gadgets, from transporters to replicators to the warp core itself. Star Trek: The Next Generation brought us the iconic communicator badge. In 1987, a long-range radio device which could fit in a pin was science fiction. [Joe] is bringing these badges a bit closer to the real world with his entry in the 2017 Hackaday Sci-Fi Contest.

The first problem [Joe] dealt with was finding a radio which could run from watch batteries, and …read more

Continue reading A Real Star Trek Communicator Badge→

An Overview Of The Dreaded EMC Tests

Posted on by

There is one man whose hour-long sessions in my company give me days of stress and worry. He can be found in a soundless and windowless room deep in the bowels of an anonymous building in a town on the outskirts of London. You’ve probably driven past it or others like it worldwide, without being aware of the sinister instruments  that lie within.

The man in question is sometimes there to please the demands of the State, but there’s nothing too scary about him. Instead he’s an engineer and expert in electromagnetic compatibility, and the windowless room is a metal-walled …read more

Continue reading An Overview Of The Dreaded EMC Tests→

World’s Thinnest Morse Code Touch Paddle

Posted on by

Morse code enthusiasts can be picky about their paddles. After all, they are the interface between the man and the machine, and experienced telegraphers can recognize each other by their “hands”. So even though [Edgar] started out on a cheap, clicky paddle, it wouldn’t be long before he made a better one of his own. And in the process, he also made what we think is probably the thinnest paddle out there, being a single sheet of FR4 PCB material and a button cell battery. This would be perfect for a pocketable QRP (low-power) rig. Check it out in action …read more

Continue reading World’s Thinnest Morse Code Touch Paddle→

Baofeng Handy Talkie Meets GNU Radio

Posted on by

There was a time when just about every ham had a pricey VHF or UHF transceiver in their vehicle or on their belt. It was great to talk to friends while driving. You could even make phone calls from anywhere thanks to automatic phone patches. In 1980 cell phones were uncommon, so making a call from your car was sure to get attention.

Today, ham radio gear isn’t as pricey thanks to a flood of imports from companies like Baofeng, Jingtong, and Anytone. While a handheld transceiver is more of an impulse buy, you don’t hear as much chat and …read more

Continue reading Baofeng Handy Talkie Meets GNU Radio→