Neophyte receiver for 60 meter

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The receiver is ready, except the RX gain potmeter which is still in backorder…

The Neophyte receiver is an easy-to-build receiver, already built by lots of people. Many radio clubs used it as a project for starting builders. It was developed by John WA3RNC and first published in QST, February 1988. The circuit can be used to create either a 80m or a 40m receiver, depending on a few capacitors. The 60m band is just in between, therefore I decided to find out the correct caps for this new amateur radio band (well… at least new in the Netherlands, from December 2015).

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How to get rid of your prototype board

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The ATmega328 microcontroller, just removed from the Arduino board, ready to start living on its own.

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 programming. But after a while you want to remove the chip from the board and place it in your first own application. What do you need to get the chip running? — more →

Tiny Tornado for 80m

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The closed box.

Many years ago I built a prototype of the famous “Pixie 2”, one of the simplest and smallest CW transceivers ever designed. The main issue is that the TX and RX  frequency is the same, so the opposite station needs to shift which he probably doesn’t know, so it takes quite some patience to get a successful QSO. Once published, lots of improved designs appeared in magazines and on the internet, one of them being the “Tiny Tornado”. Since I had some mint tins left, I decided to build this little wonder. — more →

Getting started with Arduino: morse keyer

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Close-up of the prototype keyer.

Using a paddle to operate in morse code is very convenient. But paddles don’t create dots and dashes on their own, so you need some electronics, called a “keyer”. You may use the build-in keyer of your radio, but most of them lack of functionality. You may buy a keyer at your local ham store, but these are rather expensive. So why not build your own keyer? It’s fun to do, and you learn new things. The Arduino prototyping board allows you to build the most advanced and personalized keyer that you have in mind! This article gives you a decent start for such a keyer, by implementing the basic functionality and learn a bit about the Arduino platform if you’re not familiar with this board yet. — more →

Simple signal tracer

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The completed original version of the 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 signals radiated by devices around you. It demodulates the signal, allowing the user to actually “hear” signals produced by a TV, computer, LED light, electrical wiring in the walls, etc. I showed it to different people, they all went walking around the room for a while and curiously listened to all the different signals. — more →

Adapter for LC meter

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The LC meter adapter in action.

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 is an instrument to measure capacitors and inductors. Every radio amateur should have one. — more →

70cm bicycle antenna

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My bicycle with 70cm J-pole antenna attached to the carrier.

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 branches of the river Rhine. Especially in the early morning it’s a real pleasure to enjoy all the surrounding nature.

I thought it would be nice to chat with some local radio amateurs on my way back home. I often talk to Adrian PA0RDA while driving home (by car) after work, using the local 70cm repeater PI2ZST, so I decided to prepare my bike for this UHF band. — more →

A very small active antenna

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The kit contents: extensive documentation, a professional circuit board, and all necessary components.

Small active antennas like the “mini-whip” (by PA0RDT) are very popular at the moment. They provide good reception of signals from HF all the way down to the VLF band. Here in the Netherlands Van Dijken Elektronica sells a nice kit for this antenna, and since Adrian PA0RDA was interested in this antenna, I ordered this kit and built it. — more →

Spijkerradio

Introduction

“Spijker” is a dutch word for nail, which you would normally use to hang something on the wall, or to construct wooden stuff. However, (brass) nails can also be used as as solder pad. PA0KLS used this idea to construct a receiver, called the “Spijkerradio” (nail radio). It is a nice project for starters to build their own radio.

OLYMPUS DIGITAL CAMERA

The receiver is based on the good old 0V1. This was a very simple receiver with only one tube. PA0KLS redesigned the schema to replace the tube by transistors. He also added a small audio amplifier to allow usage of modern (low impedance) headphones or a small speaker. — more →

Fox transmitter for 80m

Introduction

Fox hunting is one of the many aspects of ham radio. It’s some kind of game, where the “fox” is a little transmitter, and competitors have to locate it using a directional antenna and receiver. I already built a special receiver for fox hunting, and my wife (PD2W) built one too. So having 2 receivers it would be a nice idea to add a fox to these, to get a complete mini-fox-hunt-kit. One of the members at the club pointed me at the so-called “OXO transmitter”. I looked it up at the internet, and immediately liked its simplicity. So I started to build it.

Schematic

fox_80m_transmitter_schematic
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Pixie2 QRP transceiver for 80m

Introduction

The smallest QRP transceiver for 80 meters, called “Pixie 2”, is a very nice project to start building your own equipment. Minimum components, maximum fun. The spec’s are poor, but what else might you expect for just a few dollars?

The G QRP Club compiled a nice booklet called The Pixie File, which includes the history of this little transceiver and some variants. — more →

Your first transmitter

my1sttxWith just a few components, you can make your own morse code transmitter. The output is only a few miliwatts, but this is enough to receive on any radio in your home.

In fact, it is only a simple Clapp Oscillator with the output directly driven into a few meters of wire. The transmitting frequency depends on the used crystal. This may be any crystal between 1 and 15 MHz, higher frequencies may perhaps work also, therefore you may lower the 2 capacitors a little bit.

The transmitting frequency is not only the one shown on the crystal, but also “harmonics”: If you have for example a crystal of 3.56 MHz, then it transmits (of course) on 3.56 MHz, but also a bit at 7.12 MHz (2 * 3.56), 10.68 MHz (3 * 3.56), 14.24 MHz (4 * 3.56), etc.

The operating voltage is not critical, a 9 volt battery will do the job.

Components:

  • C1 – 100 picofarad
  • C2 – 100 picofarad
  • R1 – 10 kilo-ohm
  • R2 – 1 kilo-ohm
  • S1 – Morse key or switch
  • T1 – BC547 or any other universal NPN transistor
  • X1 – Any crystal you like between 1-15 MHz