2021-06-22 Ik was op zoek naar een creative commons afbeelding van een marifoon
Voor mijn stukje over het luisteren naar marifoon kanalen zocht ik eigenlijk naar een afbeelding van een marifoon op een schip. En het aanbod viel zwaar tegen. Via de de wikipedia pagina over het ontwerp Marifoon kom ik wel een creative commons afbeeldingen tegen van een oude marifoon, maar niets actueels. Kwa beeld zocht ik iets als een moderne marifoon zoals te koop via Inbouwmarifoons - Maritiem - hamshop.nl en dan ingebouwd op een schip, want dat is mijn persoonlijke beeld. Blijkbaar heeft nog niemand die foto gemaakt en onder creative commons beschikbaar gesteld. Termen 'marifoon', 'marine radio' en 'ship radio' in combinatie met de juiste licentie leveren niet het beeld op wat ik heb. Als ik de vraag om een open licentie er af laat kom ik best voorbeelden tegen zoals in het artikel Marifoon aan boord - Myon zeiljacht verhuur maar die zijn niet expliciet vrij te gebruiken.
2021-02-15 Snow over the Netherlands satellite image
In the weekend of 6 and 7 February 2021 the Netherlands got covered in snow and temperatures dropped to -10 degrees Celcius. In the week after that weekend temperatures stayed low and clear skies made for nice weather for outdoor skating and other wintersports. I was reminded of being on wintersport holiday. I just had to look up the available images from the NASA Global Imagery Browse Services (GIBS) and found a great image from 13 February 2021. Click for more pixels!
Satellite image of the Netherlands 2021-02-13 with snow cover.
I acknowledge the use of imagery provided by services from NASA's Global Imagery Browse Services (GIBS), part of NASA's Earth Observing System Data and Information System (EOSDIS).
2019-02-17 Sunday ISS pass with good results
Sunday had less time to be at the radio for ISS passes but one pass was ok. It started with the end of one image, one full image and the start of the next image. The audio recording of the whole pass is included.
Listen to audio attachment:
2019-02-16 One more ISS pass with good results receiving slow scan TV
After hickups in recording audio from the radio on two previous passes I rebooted the whole system (it was nagging about a reboot anyway) and I received two more partial images. Thanks to ARISS Russia team member Sergey Samburov, RV3DR for making this possible!
2019-02-16 Second ISS SSTV pass: more results
Second pass of the International space station gave me one partial picture and one complete (with some noise).
2019-02-16 Received SSTV from the ISS
In this weekend there are extra slow scan tv (SSTV) transmissions from the international space station (ISS). The ISS moves across the sky when viewed from earth so I calculate beforehand when it will pass across the sky and what the trajectory will be. I woke up in time to be outside for the first one. A low pass over the horizon and most of the pass matched a pause between transmissions, so not much image received.
2017-08-22 New QSL cards ordered, again from LZ3HI
Almost two years after I ordered QSL cards for PD4KH they ran out. I had to print stickers with the PE4KH call sign for a while to update the cards. Now I had time to make new cards and see what the options where. I promised myself nicer cards with not just the standard data but nice colour pictures on the front side so I looked at ideas, drew some things on paper and worked a few evenings in the Gimp to get the ideas into something that would survive being printed. I created files for printing at 600 dots per inch so there should be no strange printing artefacts. Image credits:
- License plate generated with Kenteken generator
- Dom tower Utrecht from Utrecht Center Central Houses Dom Dom Tower
- Shelf with radio, power supply: own picture, also available at Alan K205 power supply, tuner and radio | KvdHout on flickr
- Recumbent bicycle with radio on wooden table: own picture
2017-04-14 Going full duplex with amateur satellites, part 4 : amplifier built into the case
Today I had some time to work on the metal case for the amplifier I bought for receiving amateur satellites. I've never been good at metalwork but I think I did ok. First I made sure the place I wanted to put the holes was chosen correctly, taking the size of connectors into account. Especially with metalwork it's "measure twice, cut once". Next I drilled holes with a drill for metalwork (HSS) and used a file for metalwork to make the holes bigger. I visited the local electronics shop to get a small switch for switching the battery power on and off and added a hole for the switch. In the end the amplifier and the cables are mounted inside the case and there is a bnc connector for the Arrow antenna on one side and an SMA connector for the cable to the RTL-SDR stick on the other side.
2017-04-02 Antenna for 2m/70cm up on the dormer roof
Diamond X-30N which I bought in October on the roof were collected in the months since October and it was finally clear enough weather for a fellow radio amateur with lots more climbing experience and the right gear to climb on top of our dormer and install it. There are rubber granulate pads on the roof to avoid damage, a metal frame sold as a mount for satellite dishes to which the antenna is mounted, 4 concrete tiles in the mount to weigh it down on the roof. The coax enters the house alongside a chimney. After the work on the roof it was good to drink a beer to celebrate and afterwards I routed the cable further to my shack. The first fast test was calling CQ on a local 2 meter frequency and someone from my radio club answered immediately. The second big test was participating in a radio roundtable held on Sunday evening. This went fine, net control at a distance of somewhat over 30 kilometers gave me a 55 report (audio readability 5 and signal level 5). So the antenna is clearly doing what it is supposed to do. It's also nice to see the base noise level on the 2 meter band is near zero.
2016-12-30 The weather confirms antenna theoryItems with tag pictures before 2016-12-30
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.