2016-12-30 The weather confirms antenna theory 3 years 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.
2016-12-24 (Christmassomething) 3 years ago
2016-12-24 "Nice" view of the local noise 3 years ago
With HF conditions being bad I chose the JT65 mode in the hope of having a chance of making a contact. None happened, and the noise patterns in the waterfall display make it very clear how much local noise there is and how the local noise sources change frequencies and power. Transmissions take 50 seconds in JT65 and start right at the beginning of the minute, at each yellow horizontal line in the waterfall display. The only valid JT65 signal is in the top right corner right of the '1400' marker.
2016-12-23 (Whenever I follow a facebook link I always get the big popups that I'm not logged-in/registered. That...) 3 years ago
: Whenever I follow a facebook link I always get the big popups that I'm not logged-in/registered. That is correct, because I don't intend to do that. But some people insist on "sharing" content there and publishing the urls on the open web.
It just dawned on me. Facebook is an intranet. And like any other intranet, information goes hiding in there.
2016-12-23 Getting video to play just right with vlc 3 years ago
I wanted to project a videofile with a black screen before and after, with no visible controls on the screen where the video plays, with manual control of when the video starts and with the video starting on the second monitor. The 'why' is simple: I want to use a videoprojector which has no option to turn the screen black itself and I want the smoothest videoplay possible with no visible controls. The how was a bit more work, but vlc has enough command line options. I could not find a guess online so I did an estimated count myself:$ vlc -H --advanced | grep -ce '--' VLC media player 2.2.2 Weatherwax (revision 2.2.2-0-g6259d80) 1525This shows 1525 commandline options. So I had to find the right options. Not too much of a problem either:vlc --image-duration -1 --no-qt-fs-controller --qt-fullscreen-screennumber 1 --no-video-title-show --qt-notification 0 -f --disable-screensaver Downloads/black.png Downloads/VID_20161210_104822.mp4 Downloads/black.pngThis lets me use the vlc controls in the systray, starts playing fullscreen on the right screen, plays the static black image until I select 'next', leaves out all the indicators and ends with the other static black image. The only thing left is the fact that the audio has to select the right audio device too. It turns out vlc plays audio via the alsa emulation in pulseaudio, and I need to change that preference via the pavucontrol program.
2016-12-11 New band in amateur radio: 17 meters (18 MHz) 3 years ago
This weekend I had some time to 'play radio' and used the LW-10 longwire antenna for 6 to 40 meters because I wanted to try the 30 meter band. But there was no activity on the 30 meter band in PSK modes. So I tried other PSK31 frequencies as programmed in fldigi and ended up at 18.100 MHz and had a few contacts with Greece, Russia and Spain. The 17 meter band is from 18.068 MHz to 18.168 MHz and one of the WARC bands, named after the World Administrative Radio Conference in 1979 which allocated small parts of the spectrum in 10 MHz (30 meter), 18 MHz (17 meter) and 24 MHz (12 meter) to radio amateurs. Partly on a secondary basis (10 MHz), partly as primary user (18 MHz and 24 MHz).
2016-12-07 Popular ports for scans... 3 years ago
Currently over half of the incoming TCP SYN packets logged and dropped in my firewall are for port 23 or port 2323. According to on-line sources this is all related to the Mirai botnet and copycats of that botnet.
2016-12-05 NL-Alert? Doe mij voorlopig ook maar een echt luchtalarm 3 years ago
Vandaag was weer een NL-Alert controlebericht en als ik zo de geschiedenis inkijk van ontvangen infoberichten op mijn telefoontoestel denk ik dat het voorlopig niet verstandig is het 'ouderwetse' luchtalarm uit te schakelen. Ik heb een dual-sim telefoon, die op de netwerken van Vodafone en T-mobile zit. Dus in theorie krijg ik 2 keer per jaar 2 berichten. Uit de huidige geschiedenis:
Op 2016-06-27 was er een echte reden tot nl-alert, en die heb ik via vodafone ontvangen.
- 2015-12-07 12:00: om 12:01 ontvangen via t-mobile
- 2016-06-06 12:00: niets ontvangen
- 2016-12-05 12:00: om 12:03 ontvangen via vodafone