[dajjhman] wrote in to show us how he added a microphone jack to the handset of his Yaesu radio while retaining the DTMF functions. He states that there were some adapters available on the market, but they are non standard and didn’t really fit his needs. The modification itself is pretty simple, especially with his great documentation and clear pictures. For anyone else who might need this setup, this should be a great resource.
[W1VLF] is on a quest to communicate over long distances with a 9 kilohertz transmitter. He built this giant coil with that in mind. A round concrete form was used as a base and wound with magnet wire by hand. We’d recommend building an automated winding device, but this method seems to have worked. Operating at 50 Watts on the air-core coil at 8.97 KHz he was able to pick up the signal at a distance of 5 kilometers. It’s not breaking any overall distance or portability records, but on a project like this the quest is where the fun is at.
[Thanks Drone]
[Terence Bordelon] sent in his impressive UAV (Unmanned Arial Vehicle). The hack is a culmination of his other projects. It can be turned to fully automatic at the flip of a switch. It will fly itself to gps way points, land, and take off. The UAV has a range of 100km thanks to his home built RF Unit which runs on ham bands. The brains of the setup is his custom IMU (Inertial Measurement Unit). The unit is controlled by his ground station which either allows him to fly it normally or toggle through the various modes. [Terrence] is also a game developer and has worked on many popular titles such as Zoo Tycoon 2 and Ratchet and Clank.
Host of the Soldersmoke podcast, [Bill Meara], contributed this guest post.
WSPR is a new communications protocol written by radio amateur and Nobel Prize winner [Joe Taylor]. Like the very slow QRSS system described in a previous post, WSPR (Weak Signal Propagation Reporter) trades speed for bandwidth and allows for the reception of signals that are far below the level of radio noise. WSPR takes “low and slow” communications several important steps ahead, featuring strong error correction, high reliability, and (and this is really fun part) the automatic uploading (via the net) of reception reports — [Taylor]’s WSPR web page constantly gathers reports and produces near real-time Google maps of showing who is hearing who. The WSPR mode is very hack-able: [Bill Meara] is running a 20 milliwatt homebrew transmitter from Rome, Italy that features an audio amplifier from a defunct computer speaker pictured below. This contraption recently crossed the Atlantic and was picked up by the Princeton, New Jersey receiving station of WSPR’s esteemed creator, [Joe Taylor]. Continue reading “WSPRing Across The Atlantic”
Host of the Soldersmoke podcast, [Bill Meara], contributed this guest post.
While the rest of the world is moving toward high speed broadband, some hams—including one Nobel Prize winner—are going in exactly the opposite direction. Our ‘QRSS’ mode makes use of an unusual mixture of modern digital signal processing (DSP), ancient Morse code, and simple homebrewed transmitters. Very narrow bandwidth is desirable because this reduces the noise in the radio communication channel, greatly improving the S/N ratio. But Shannon’s communication theory tells us that narrow bandwidth comes with a cost: slow data rates. In QRSS, beacon transmitters using only milliwatts churn out slow speed Morse ID signals on 10.140 MHz that are routinely picked up by DSP-based receivers on the other side of the globe. Many of the receivers, ‘grabbers’, have visual outputs that are available online in real time. QRSS has been getting a lot of attention on the Soldersmoke podcast and on the Soldersmoke Blog. For more information check out this overview and the hardware involved. Here’s a gallery of received signals.
This applies more to older vacuum technology than your average solid state hardware, but [Richard] put together an interesting project. It’s designed to test a component for its breakdown voltage without destroying it. The general idea of the ‘BVT’ is to increase the voltage applied to a device until some current leakage is detected. Of course, any device that includes notes on probable arc length in relation to kilovolts is awesome by definition.
