Peter Rachow (DK7IH) built a 14MHz SSB QRP Micro-transceiver into a cigarette packet size case: This article describes the “Cigarette Pack” SSB QRP transceiver” for 14MHz that I first had mentioned some months before. Recently, when taking it from the shelf, the transceiver dropped to the floor and was severely damaged. This lead to serious […]
Ryan Flowers writes, “A fun project for every QRP enthusiast is an L-match tuner. We’ve built a couple here at MiscDotGeek and our latest build inspired Billy Dunn (AF5HD) to build a similar tuner. We have to say, this one turned out better than ours did!” More details on MiscDotGeek blog.
Steve (VE7SL) has built a Jones Power-Oscillator using a pair of 6L6s and wrote a post on his blog detailing its assembly.
Pete Juliano, N6QW, has written an article on how to do CW on a homebrew SSB rig: The Answer is Not a Flippant: Carefully! Author’s note: A friend in VK4 land made an inquiry about CW operation. I find that 99.99% of my operating time is SSB. But others spend a greater time on the […]
Simonhk (G0FCU) wrote a series of posts on building homebrew SDR HF transceiver: However, what you might notice is the presence of image products in the waterfall. The processing of the signal suppresses all but the very strongest of these so they don’t appear as audio but it is mighty confusing when they are on the […]
Sven Krasser blogged about his 6502-based homebrew 8-bit computer build: After completing my VGA Generator project a while back, I’ve embarked on a new electronics project: building a simple 6502-based homebrew 8-bit computer on a breadboard. There are a bunch of similar projects online from which to draw ideas. Some projects set constraints such as only […]
Pete Juliano, N6QW, has a nice build log on his newest version Heathkit 40M SSB Transceiver: What are you thinking — I am not trying to break any world record? My XYL asked me that question today — why are you building another rig? Followed up by a snide comment that I had so many […]
g4fre built his own PIHPSDR, that is available at github: Having seen the Apache-labs version of the PIHPSDR I wanted to customise it to fill my needs, so I needed to build my own All the needed information , with the software, is at John Melton’s github site github.com/g0orx/pihpsdr The hardware shopping list includes. RaspberryPi […]
A simple DIY dummy load project from Flathagen: I have created a simple 50 Ω dummy load to test transmitters. I also added a simple RF diode detector so I can measure the peak voltage, and calculate the power. The dummy load consists of eight 100 Ω resistors rated at 2 W so the load […]
Dave Richards AA7EE has published an article about Georges F6DFZ’s homebrew regen receiver: Several months ago, Georges F6DFZ sent me pictures of a Manhattan project he had just completed, using Rex’s MeSQUARES, and I have waited far too long to share it with you. It began life as a copy of the Ten Tec 1253 regen, but […]
Sverre Holm made his own powerpole voltage and current meters: Powerpole voltage and current monitoring is quite nice to have. One can buy commercial meters, but due to the availability of nice and cheap modules, it is very easy to make them oneself. To the right you’ll see my combined voltage and current meter as well as […]
Pete Juliano, N6QW, has been working on a transceiver project. He writes: Today we complete most of the mechanical work and the only item remaining is the RC Filter to turn the Square Waves into Sine Waves for the tune signal. We have had it on the air in the current box as you always […]
Flathagen has made a DIY EMRFD Direct conversion 40m receiver in a tea caddy: I woke up one day eager to build something simple (at least I thought is was simple) and opened up the first chapter in EMRFD and decided to build the 40m direct conversion receiver. I already had most of the components in […]
Flathagen blogged about his DIY SWR meter project: The circuit is based on two AD8307 log amplifiers, which are connected to the forward and reflected ports on a directional coupler. The AD8307 amplifiers gives a DC voltage of about 25mV/dB of the input signal, which is amplified using an opamp (LM324). The opamp also provides the […]
Sverre Holm writes: Some time ago I noticed that the Ublox Neo-7M GPS has a 10 MHz output which is locked to the GPS system’s accuracy. Most people kept saying how useless it was due to excessive jitter unless it was cleaned up with a phase locked loop of some sort. But at the same […]
A HC508 Amiga 500 accelerator card project from mc68k: Finally, the project has reached a stage when complete system tests are possible The integrated CF + IDE allows running the complete OS 3.1 with WHDLoad. Key feaures: 68HC000 CPU running at 50 MHz (100% MC68000 compatibility) 40 pin IDE connector for HDD, CD ROM etc. […]
Flathagen blogged about his DIY directional coupler: It is simple to construct the directional coupler. The transformers are FT50-43 toroid cores with 32 turns of 24 AWG enamel wire. The primary winding is simply a piece of RG58 through the torioid (i.e., one turn). Different designs use different toroids and number of turns. I settled […]
Voja Antonic writes: When you live in a totalitarian, controlled and “happy” society, and you want to be a hacker, you have to hack the social system first. Being just an engineer doesn’t cut it, you have to be a hypocrite, dissident and a smuggler at the same time. That’s the motto of my personal […]
The Arduino and Cloud-based homebrewing controller by Martin Kennedy of TheBedroomLaboratory: It’s just a basic site, based on this Scotch.io tutorial, which is currently plotting the temperature in my sitting room. It’s got a PHP backend (Laravel framework with RESTful API), MySQL database and an AngularJS frontend with (n3-chart/d3 for the graph). In the house, I’ve whacked […]
Here Jeri Ellsworth concludes her presentations on a homebrew TSA type body scanner by focusing on the components and coding. An FPGA is used for processing of the video signal as an alternative to a PC. The use of a “virtual ground” is an interesting aspect of the signal amp circuit.