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How to get rid of your prototype board

When you started discovering microcontrollers, you probably bought some kind of evaluation or prototype board. The microcontroller chip itself is placed in a nice socket on a PCB, surrounded by power circuit, some I/O, and RS232 or USB connector for…

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Step attenuator kit

I’m the proud owner of a MiniVNA for quite a few years already. One of its features is that you can use it as an RF signal generator. However, the output power cannot be adjusted, so I needed an attenuator.…

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Short DL6WU yagi for 23cm

In the previous Winter I built a HB9CV-in-a-box for 23cm for my uplink to the local ATV repeater PI6ATV. Although this antenna works nicely, its gain just isn’t enough when their 23cm preamp is broken (which, unfortunately, is the case…

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Simple signal tracer

I found a really simple project for kids to attract them to homebrewing and hamradio. It is also very nice for people who want to learn soldering electronics. It’s a “signal tracer”, which means it detects all kinds of RF…

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5/8 Wave vertical antennas for HF

Lots of radio amateurs build their own verticals. Most of them tend to stick to vertical antennas with a 1/4 or 1/2 wave sizing. Just a happy few build a 5/8 wave vertical antenna. This is remarkable, since the 5/8…

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Adapter for LC meter

The dutch electronics shop Van Dijken Elektronica sells a nice kit to build your own LC meter. The kit includes a professional PCB, all components, building instructions, prepared case and leads. The kit takes an evening to assemble, the result…

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Altoids L-tuner

A while ago Tjeerd PA3GNZ donated me some Barkleys mint tins (identical to the famous Altoids tins), which are rather popular by QRP builders to house small homebrew stuff. Two weeks later I found a czech webshop, offering a kit…

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70cm bicycle antenna

During the summer season I sometimes travel to work by bike. It’s a 21 km trip through the countryside, passing cornfields, orchards, deer and spoonbills. The road includes dikes and bridges, and even a ferry to cross one of the…

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PC6REC ATV station

During the 2014 edition of the REC Fielddays I facilitated a live videofeed,  broadcasted throughout the Netherlands. Using three cameras and a bunch of (mostly) vintage hardware, the live stream was uplinked to the local ATV repeater PI6ATV. Viewers could…

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Stereo to mono converter

My TV camera generates stereo audio, like most cameras do. However, my local ATV repeater only supports mono audio. So to transmit a nice audio signal with my TV pictures, I needed a way to convert the stereo signal to…

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PoRG v2

A couple of years ago I built my first PoRG (abbreviation for “Power over RG-cable”), a simple phantom power supply to power some device over antenna cable (e.g. a preamp, active antenna, coax switch, etc). I recently built an active antenna…