2016-12-30 The weather confirms antenna theory 2 months ago
Last afternoon I hung up the endfed antenna outside to make some contacts on different radio bands. This morning I noticed it was all covered in frost due to a night with temperatures below freezing and with lots of mist. So I took the camera for some pictures of the frost on different parts of the antenna, gathered at flickr: img_3365 | Coil in endfed antenna with ice growth | Koos van den Hout | Flickr. After I took a set of pictures I started transmitting PSK31 on the 20 meter bands at 50 watts power. And my antenna theory tells me that the part of the antenna radiating the best is where the most current of the standing wave happens which is right after the transformer in an endfed antenna. Which I got confirmed: img_3380 | Endfed antenna with ice growth on transformer | Koos van den Hout | Flickr was taken before I transmitted and img_3378 | Result of using the enfed antenna: ice vaporized | Koos van den Hout | Flickr after. The ice is gone on the first part.
2016-10-13 A few pictures added to The Transmission Gallery 5 months ago
I am a fan and regular visitor of The Transmission Gallery and a photographer. But it is not very often I can submit pictures for The Transmission Gallery as it is aimed at transmitters in the United Kingdom. But on our recent holiday in the UK lake district I noticed on one campsite I had a direct view of a TV transmitter tower. And good, fast mobile data from the same tower. So I took a walk to photograph the transmitter so I could add something to The Transmission Gallery. So, now available to the general public: Keswick - Pictures taken August 2016 - The Transmission Gallery. My previous addition to the gallery was in 2010: Wooler - The Transmission Gallery. We have visited the United Kingdom a few times in between but never got close to a transmitter site or the weather hid the site completely in clouds or fog.
2016-09-09 First part of the lightweight outdoor radio antenna: the balun 6 months ago
After building and testing the Sotabeams dummy load I had time to work some more on the ordered parts. The main part of the order at Sotabeams was parts for outdoor antenna building: an antenna centre and 1:1 balun and linked dipole portable HF antenna kit. The HF antenna kit does include parts for a simple centerpiece/balun but I decided to get a separate balun that should make these things easier and/or sturdier. The balun build was doable, but soldering coax on the connectors gave a bit of a problem as the solder did not want to flow on those connectors very well. Maybe clean them next time or even sand them a little to make that easier. Next part will be the rest of the HF antenna for which I will need an antenna analyzer and time outdoors in the daylight.Read the rest of First part of the lightweight outdoor radio antenna: the balun
2016-07-24 My own outgoing eQSL design 8 months ago
I decided the picture of the recent outdoor activation was nice for a personalized eQSL design. It took some serious work with Gimp to make it turn out like I want it, and that was just with one image to work with and I'm still not completely satisfied. In the result will be an overlay at the bottom with the details of the contact. I used the Kenteken generator by Remco van Zuijlen to generate the callsign image.
2015-09-20 Better powersupply for the amateur radio setup 1 year ago
I got annoyed with the PC powersupply I used for the amateur radio setup, output power was dropping below reasonable values at any load. The PC power supply was supposed to be able to give me 40 Ampere at 12 Volts but I saw the 12 volts drop easily to below 10 Volts at a load of less than 10 Ampere. So, time for a better power supply. I kept an eye on any nice secondhand offers and found an Alan K205 powersupply for sale which would give me 13.8 Volts at a sustained maximum of 20 Ampere (22 Ampere peak). I made a reasonable offer which was accepted immediately and went to pick it up. It's an old-fashioned transformer and regulator powersupply (not a switching mode powersupply), it's big and it weighs a lot. And it works like I want it, with voltage never dropping below 13 Volts even under heavy load.
2015-09-20 More QSL cards 1 year ago
Radio amateurs exchange QSL cards to confirm contacts. Recently I received a whole batch of new ones. I usually look at the 'backside' first since that has the details about the QSO, but some cards have really nice fronts too!
2015-07-19 Received an image from ISS 1 year ago
This weekend gave me another chance to receive slow-scan TV (SSTV) images from the International Space Station. These images were transmitted to commemorate the 40th anniversary of the Apollo-Soyuz Mission. The usable passes from my home location were at a bit early times: 05:30, 07:10 and 08:43. And I really like to sleep out on Sunday, especially since I'm currently quite tired. So I opted to only go for the 08:43 pass and see what I could get. Timing of images was also bad: when I started to hear the ISS I heard the tones of the end of an image. But later a new image started and I managed to receive the whole image although some noise in the middle (some building in the way probably) made qsstv break the image in two parts, which I fixed using the gimp. Used equipment: laptop with gpredict for calculating azimuth/elevation and frequency correction, a tripod, the Arrow antenna, the FT-857 radio. I recorded the audio on the laptop with audacity and did the decoding with qsstv later, which gave me the opportunity to try it a few times to get the best decode.
2015-05-30 Incoming QSL cards too 1 year ago
Sending outgoing QSL cards also results in incoming cards:
2015-05-29 Outgoing QSL cards ready to send 1 year ago
Finally some time to write outgoing QSL cards. 32 of them. Maybe I need to start ordering them, this was after I printed and cut a 'large' batch. Already all filled in and ready to get to the QSL bureau.
2014-08-16 (#) 2 years ago
Friday evening I had time to work on the 'digimode' interface for the FT-857 radio. I set up a breadboard with the audio transformers and started making cables from the transformers to the USB audio interface. Then I added the cable to the radio on the other side. All of the earlier mentioned interfaces had resistors to regulate the signal level so I started with 12K resistors between the radio and the transformer in the radio to computer audio path. This gave me a weak signal when recording the result with audacity on the computer so I switched to a 6k8 resistor which improved audio but it still wasn't great. So the resistor was replaced by a simple wire which gave me good audio when recording from the PA00NEWS transmission on the PI3UTR repeater. I did notice some low hum while recording, but I realized that was just the CTCSS tone on the repeater output. Normally this tone is filtered out when hearing the audio through the speaker of a radio.
2014-07-25 I searched for and found a better radio transciever: the Yaesu FT-857 2 years ago
For a while I have been considering my wishes for a more elaborate amateur radio. What I want to do with it is continue and expand the use of amateur satellites, and try to get into PSK31 on HF, starting on the 20m band. So a list of must haves and should haves arose: all-mode, portable, computer assisted tuning, HF support, 2 meter and 70 centimeter and an increas of power from 5W. Adding it all up and looking for a reasonable price I ended up considering the Yaesu FT-857(D). It's in the middle between the FT-817 (too low power, still 5 watts) and the FT-897 (too heavy: 3.9 kilograms). And a reasonable pricetag, were other amateur radio brands have nothing comparable or at a much higher pricetag. I went looking for a second-hand one and when we got back from holiday a nice one (FT-857 with DSP and installed filter, and a remote control+DTMF hand microphone) showed up from Communicatie Centrum Venhorst - Hilversum and I bought it. Picked it up this week, and I am learning using it. I listened to SO-50 this evening using this radio with a lot of wires on the table in the backyard.
2013-08-24 (#) 3 years ago
Some soldering work on the HF convertor kit for the rtl-sdr stick today. I noticed I haven't mentioned the progress of this electronics building work yet.
HF active antenna kit PCB printed side.The main board of the HF active antenna kit (a mini-whip, based on the excellent work by Roelof PA0RDT has done) is finished. Soldering the antenna-plate to the amplifier has failed sofar: soldering two bigger areas of copper together with a soldering iron designed for electronics work fails. And a small inductor between antenna plate and amplifier might be a good idea too reading the design, it would improve reception above 20 MHz where I want to have a listen to the 10 meter amateur band too (28.000 MHz - 29.700 MHz). There is also an indicator led included which I will solder in place once the print is tested and ready to be mounted in a housing (PVC pipe seems to be quite popular for this). I plan to mount the led in such a way the housing doesn't have to be opened to check the status.
HF active antenna kit PCB component side.
HF upconvertor kit PCB printed side.Next soldering project is the HF upconvertor kit. I'm working on it at the moment, finding time for soldering and working very carefully. Not careful enough: the kit contains one length of wire for winding 4 coils and I found out at the fourth coil that I took a bit too much wire for the first three ones. Time to visit the electronics shop again, to get wire for winding coils. I checked the collection of parts at the radio club but there was no winding coil wire of 0.8mm. I ordered the kits from Van Dijken Electronica, a Dutch shop in electronics, quite popular with amateur radio hobbyists.
HF upconvertor kit component side.
And yes, it's more difficult than first thought to take usable pictures of printed circuit boards.
- Bouwpakketje actieve antenne 10 KHz - 20 MHz(max 30 MHz) Kit mini-whip antenna
- Bouwpakket HF converter voor de rtl sdr sticks DC - 65 MHz Kit HF convertor
2013-07-28 (#) 3 years ago
I took some pictures of the PA0FBK coax antenna in full action.
2013-06-27 (#) 3 years ago
Using the QSL card creator at RadioQTH I designed my own QSL cards. I searched for a long time for a good picture to use: I wanted something from the area where I live, radio related and a picture I made myself. I used pictures I took of the Zendmast lopik te IJsselstein / Gerbrandytoren as nice pictures of broadcast antennas. I don't have anything to do with the antennas there other than being a satisfied user of the PI3UTR repeater, but the Gerbrandytoren has always been part of my view when I grew up so it is a radio-related landmark to me.
Version 1 qsl card PD4KHI made two versions, one with a 'portrait' picture and a white background and one with a 'landscape' picture as background. I'm not sure which version is the best.
Version 2 qsl card PD4KH
2013-01-31 (#) 4 years ago
I found a spot were I could receive PI3UTR reasonably fine on the ground floor, hanging the transceiver upside down from the curtain.
The Wouxon KG-UVD1P hanging upside down for optimal reception
2013-01-14 (#) 4 years ago
This morning it was cold on my recumbent bicycle, frost formed on the speedometer. Brrrr!
2012-11-26 (#) 4 years ago
One thing I love to do here at BA HQ is feature beautiful, time-lapse videos of the night sky. The advent of high-definition digital cameras has led to an explosion of these videos. If the photographer takes care, the result can be an ethereally lovely and (ironically) other-worldly feel to the animation. My pal Christoph Malin is one such photographer. He is a member of The World At Night, a global effort to make more people aware of the beauty of the night sky. Over the past year and a half, he’s been traveling to the volcano island of La Palma, one of the Canary Islands off the coast of Morocco, filming the landscape and skyscape there. He generated over a terabyte of raw images (!!) and put them together to create this gorgeous time lapse video, Island in the Sky.You want to watch this in HD and fullscreen.
Via Time-lapse video: clouds and stars over the volcanic La Palma Canary Island
2012-10-01 (#) 4 years ago
Een wandeling bij Lage Vuursche door het gebied "Nonnenland" aan het eind van de middag, en toen zagen we daar herten.. en was ik erg blij snel de camera gereed te hebben en een aantal foto's te kunnen maken.
2012-09-07 (#) 4 years ago
Another beautiful timelapse compilation... watch it in HD + fullscreen.
2012-08-17 (#) 4 years agoOlder news items for tag pictures ⇒
En nog een leuke 'computerkamer' set gevonden via google image search: Computerkamer van cba. Compleet met 19" rack.