Kenwood interface for visually impaired radio amateurs

[Image]

The interface, ready to be mounted to the radio.

This article describes an add-on for modern Kenwood transceivers to allow visually impaired operators to use these radios with a VS-3 or VGS-1 voice synthesizer. I built this interface for Adrian PA0RDA (using a TS-2000), but I’m almost sure that more visual impaired radio amateurs will be interested. The add-on is easy to build, most of the work is mechanical while the electronics are easy. — more →

PoRG v2

[Image]

The PoRG v2, in a nice blue box, now including a built-in power supply.

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 for Adrian PA0RDA, and since his tests were very successful he wanted to have his own PoRG. For me this was a nice opportunity to reinvent this little thing:

  • I included a built-in power supply, so no external power supply is needed anymore.
  • The built-in power supply also prevents the PoRG from moving around your shack due to the forces of the connected cables.
  • It has different connectors for hooking up the transceiver/receiver and antenna, making it more difficult to accidentally swap the cables, insert DC power into your radio and see smoke appearing through the vents of your rig.

— more →

Best dutch participant in AGCW contest

[Image]

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

[Image]

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 →

ATV transmitter for 23cm

[Image]

Front view of my fully assembled 23cm ATV transmitter.

Although I was already able to receive the local ATV repeater PI6ATV, it has been a wish for about 8 years to be able to uplink too. So I once bought a couple of modules from PE1ACB that would allow me to do so. However, due to lack of time and other priorities the modules lost my attention and ended up on some shelf. Since I started my new job I have more spare time, which I spend (among other things) on this fantastic hamradio hobby. So then I remembered those modules. I designed a front panel and bought a case, switches and connectors. — more →

A very small active antenna

[Image]

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 →

30m QRP transceiver – Part 1

[Image]

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

[image]

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!

— more →

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.

— more →

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

[image]

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.

— more →

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 →

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 →

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:
pacc2014_field_1200px

  • 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)

— more →

J-pole antennas for HF bands

Introduction

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.

— more →

Automatic antenna tuner using an Arduino

Introduction

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 →