Best dutch participant in AGCW contest


My Junker straight key.

The AGCW is a german club of morse code enthousiasts, maybe the best CW club in the world, with lots of foreign members as well. They organize all kinds of small activities, related to CW off course, one of them being the “HandTasten Party” (HTP, straight key party). In this contest the only way to make a QSO is by using a straight key. So no bugs, no keyers, no computers, just the classic way. There are actually two HTP contests, one is on the 80m band every first Saturday of February, and the other on 40m every first Saturday of September. This year I participated in the 80m contest again, as a nice warming-up for the PACC contest. — more →

30m QRP transceiver – Part 2


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


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 →

Summary of our 2014 PACC contest


Adrian PA0RDA operating his Kenwood TS-2000

Another PACC contest for me and Adrian PA0RDA. This year we participated in the D1 multi-operator two-transmitter class for the first time. We did a very good job, we improved our own score, again, which is always our main goal (besides having fun). The weather conditions were rather poor again, we had lots of wind during the contest. Luckely all our antennas survived this time, even with a really strong gust of 40 m/s!

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HB9CV-in-a-box antenna for 23cm

The antenna is mounted in my pole, just below the 23cm LNC. Both are pointing at the PI6ATV repeater.

The antenna mounted in my pole, just below the 3cm LNC. Both are pointing at the PI6ATV repeater.

The HB9CV has been a popular antenna for decades, especially on the 2m band where it is commonly used for direction finding (foxhunt). Others create arrays of HB9CV antennas for DXing. Since I needed a simple antenna for 23cm (to uplink to the local ATV repeater PI6ATV) I thought it would be nice to use this HB9CV design.

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ATV image generator using the Raspberry PI

20140101_145231I’ve got a Raspberry PI for a while already, but it hasn’t been very useful until today. I recently started setting up my own ATV (Amateur TeleVision) station. I needed a simple solution to generate a test pattern, something to broadcast when testing my ATV transmitter. Since the Raspberry PI has a composite video output, there must be a way to let the PI do the job.

I found several projects on the internet. However, they produce only HDMI output, no composite video. After browsing the web, I found a very easy solution using the Linux fbi command. This command allows you to load a picture in the frame buffer of the graphics adaptor. — more →

First ATV transmission


My first 23cm ATV transmission (camera output with text overlay), received by PI6ATV.

I’m working on a 23cm ATV transmitter. A couple of years ago I already bought some modules from PE1ACB: a baseband modulator, a 23cm ATV transmitter (output 1 watt) and a controller unit. Today I hooked up all modules, together with a title generator, a camera and a HB9CV antenna for 23cm. When powering on, I was able to transmit/uplink to the local ATV-repeater PI6ATV and see the result at the repeater’s output  at 10 GHz.

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Is our 80/160m HEDZ suitable to work Americans at 160m?

Adrian PA0RDA and his Drake TR-7

Adrian PA0RDA and his Drake TR-7

Last weekend was the yearly ARRL 160m contest. Adrian PA0RDA and I were still a bit in doubt about our HEDZ antenna for 80 and 160m: is it suitable to work American and Canadian stations at 160m? So far we never heard any station from that area on that band, so Adrian decided to bring his Drake TR-7 for the weekend and try to work these countries during the 160m contest, probably the best opportunity for this test. — more →



“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.


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 →

All antennas up again

All antennas are in place already for the 2014 PACC contest. Meanwhile they allow me to work HF bands during the Winter season.

Last year the field was in such a bad shape, that we were not able to setup the half extended double zepp for 80 and 160m. This year we had some nice weather in November, allowing us to get all antennas up in a rather short time.

We get used on erecting all those poles, since we do this at least twice a year: at the start of the winter and at the REC fielddays in June. Except the HEDZ, all antennas can be setup by one single person.

My 2013/2014 antenna setup for HF: monoband verticals for 10, 15, 20 and 40m; HEDZ dualband antenna for 80 and 160m.

My 2013/2014 antenna setup for HF: monoband verticals for 10, 15, 20 and 40m; HEDZ dualband antenna for 80 and 160m.

First antennas placed

This year Adrian PA0RDA and I hope to be back in the PACC contest. Our main goal is always to improve our own score, combined with having lots of fun on the bands and test our homebrewn antennas. This will be the antenna setup for PACC 2014:

  • 10m: monoband J-antenna
  • 15m: monoband J-antenna
  • 20m: monoband 5/8 vertical
  • 40m: monoband 1/4 vertical
  • 80m: zepp (new!)
  • 80/160m: half extended double zepp
  • Beverages to Southeast Asia and Australia (not sure yet)

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J-pole antennas for HF bands


I’ve been using J-pole antennas on the 2m band from the first day I got licensed. They perform very well, are easy to construct and are cheap. Since Adrian PA0RDA and I have been experimenting with vertical antennas for HF, we came to the idea to try those J-poles on HF.

This idea is not new. Many radio amateurs have tried this before, like DK7ZB. The J-pole antenna is almost identical to the Zepp-antenna, which is a still a popular HF-antenna. — more →

Bad luck

Since Adrian PA0RDA was ill during the contest weekend, and we were not able to setup all antennas due to poor condition of the field, we decided to skip the PACC contest. However, on Sunday morning I could not resist to give away some points, so I made a bunch of CW QSO’s on 15m. We hope for more luck in 2014.

Wind, wind, wind

December was a very windy month. Most antennas did held, however the fibreglass pole of the 20m vertical broke. We contacted the supplier (DX-Wire, Germany) and luckely spare tubes were available for a few euro’s. So we ordered a replacement tube, and also ordered 2 more masts for future use.

We were not able to do lots of testing on the antennas, since work lasted too much time. So that has to wait for the next month.

Perfect weather to erect all antennas

November starts with 2 weeks of mild weather, with lots of sunshine and no rain. This means that the corn field is rather dry now and easy to walk on. In the first weekend I put lots of tonkin poles in the ground to mark all antennas. I also rolled out the HEDZ (100m) and the beverages (2x 80m). The beverage is nearly ready already, including matchbox and feeder. Wytske helped me to erect the 15m center pole of the HEDZ. Within a couple of hours a kestrel already liked the pole and is now regularly seen sitting on the top.

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Automatic antenna tuner using an Arduino


OLYMPUS DIGITAL CAMERAThe Arduino board is a fantastic tool for rapid prototyping, and can help radio amateurs in lots of homebrew projects. I wanted to demonstrate that it is very easy to build an automatic antenna tuner with the Arduino. I connected an old SWR meter to one of my Arduino boards. Furthermore I build a simple L-tuner with a fixed coil and a rotating capacitor (400pF). The capacitor is driven by a servo, also connected to the Arduino. By doing a full sweep with the capacitor, the Arduino tries to find the position with the lowest SWR. After the sweep it turns the capacitor to that position. You can view the video below to see the tuner in action. Mind the SWR meter (right needle) in the back while the capacitor is rotating. — more →

First preparations for the PACC 2012

We had some nice weather in the last weekend of October, so I went into the corn field to do some long walks: setting up the new beverages (length: 80m each) and the HEDZ. We bought some new, higher poles this summer for the HEDZ, the center pole will be almost 15m tall now. The poles are not erected yet, but I was on my own that weekend while I need 2 or 3 people to get the poles up.

What are the plans for PACC 2012? Well, we will set up all antennas of 2011 and add some new ones. We built 2 beverages during the REC fielddays, which will be used in the contest now. And we will build a small array of verticals for 10m, since it will be likely to have some propagation on that band during the contest.

Squalo antenna for 6m


squalo-6m-1Adri PA0RDA, a friend of me, is trying to do some DX on 6m for a while now. His antenna position is very poor: he lives in the bottom flat of a 5-floor building. He has a balcony on the rear (south) side, but high buildings are very close, he has no direct sight in any direction. At the balcony he has a Diamond V2000 vertical antenna for 6/2/70, and an MFJ loop antenna for 15-40m. The 6m band is his most popular one, since he get best results on this band. However, since most DX on 6m is horizontally polarized, he needed a horizontal antenna. I remembered an all-direction horizontal antenna made by Jan PA3EGH (one of the members of the local radio club). So I contacted him, and he pointed me at his website. It was the “Squalo” antenna, or square halo. In fact, it’s just a square folded dipole. It radiates in all directions, with -4dB gain on the sides (compared to the front and back side).

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Contest after heavy winds

Looking a bit tired at the contest final...

Looking a bit tired at the contest final…

The first weekend of February was really windy. The rough wind ruined the just finished HEDZ, and nearly nocked down the other antennas. And there was nothing I could do, since I was suffering from influenza. I recovered during the next days, and on Friday (just one day before the start of the contest) Adri PA0RDA helped me to fix the antennas. The main pole of the HEDZ was broken, but luckely it was easy to repair. We checked all pins and guys, measured all the antennas, resoldered an inductor in the 40m matchbox, etc. In the afternoon the antennas were in top condition again, so we could start rebuilding the shack.

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Finalizing the antennas

Thanks to a interesting article about the so called Half Extended Double Zepp (HEDZ) by W5DXP we managed to get our EDZ working om both 80m and 160m. The antenna is working fine now on 80m. I couldn’t test in on 160m yet, because my own rig (IC-730) doesn’t work on that band, but the measurements with the MiniVNA show a acceptable SWR between 1800 and 2000 kHz. When breaking up we will do some physical measurements to see what the exact size of the dipole and feeder is. The (H)EDZ is also a little bit lifted now, the center is 12 meters above the ground, the endpoints 8 meters.

We also erected the remaining antennas: the 1/4 wave vertical for 40m, and the HyGain AV-12AVQ for 10/15/20m. In the upcoming weeks we will extend the number of radials for the 40m vertical.

Setting up antennas on a corn field is not really easy. Ok, there’s no corn in the winter, but the field is very wet and muddy. When the temperature drops below zero, the field becomes icy, and above zero the amount of mud under your (wooden) shoes grows with every step.