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 →

First experiences with my 30m QRP transceiver

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Final shot of the rig, including labels, key and headphones.

This year I built a very nice 30m QRP transceiver, based on a design by Onno PA2OHH. Meanwhile I have used this rig a couple of times, and did some measurements too. This article tells some of my experiences with this great little box. — more →

Altoids L-tuner

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My 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 called “Altoids L-tuner”. This kit perfectly fits in such a tin. Since this tuner would be a perfect add-on for my 30m QRP transceiver, I immediately ordered it. — more →

30m QRP transceiver – Part 4

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Inside view of the radio, including all modules built so far.

Since I finished all modules for the receiver part (power, LF, VFO and RX-board), it was getting time to put everything together and place it in a nice case. Onno PA2OHH (designer of this radio) managed to put the complete transceiver in a single Teko 4B case, so I ordered that same box. Actually I already bought it at the beginning of the project, to help me dimensioning the modules. With such limited space, planning the physical layout of the radio (both the front panel and the inside) is very important. — more →

30m QRP transceiver – Part 2

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The finished VFO, just before closing the lid.

Building a stable VFO is challenging. Oscillators tend to drift away due to (very small) temperature fluctuation, or due to small capacitive changes in the direct environment (e.g. the frequency changes when you move your hand towards the oscillator). The VFO used in my 30m QRP transceiver is not different from others, so I had to deal with the same issues. — more →

30m QRP transceiver – Part 1

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The first modules of my 30m QRP transceiver.

This summer I want to go walking in the beautiful highlands of Scotland, together with my wife. The mobile phone coverage in this desolate area is none or poor, but hey… I’m a radio amateur! For a daily “sign of life” I need a lightweight transceiver, and 30m (10.100 – 10.150 MHz) seems to be a perfect band for this purpose.

After browsing the web for designs, I stumbled on the website of Onno PA2OHH. Besides lots of other interesting QRP projects, I found his NiceRig 40-30 QRP Transceiver. I immediately fell in love with this design and decided to build this thing.

Building this rig takes quite some time, so I publish this project in different posts, showing you the progress of this project. — more →

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