2016-12-30 The weather confirms antenna theory 2 weeks 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.
2016-06-23 A serious thunderstorm somewhat counted 6 months ago
Last night a serious lightning storm passed and it got counted, but clearly with the same problems in counting as seen before in counting thunderstorms from the shed while radio activity causes a lot higher counts. Looking at the graphs for thunderstorms counted from the attic before I was active on HF radio there is quite a difference in numbers. I think I want the lightning strikes counter back up in the attic but with a low-pass filter somehow to filter out false counts from amateur radio traffic.
2015-08-31 A serious thunderstorm counted 1 year ago
We finally had a serious thunderstorm last night, making us almost jump from the bed at one moment. And the lighting strike counter saw that thunderstorm nicely. It's quite clear the counts are lower now the sensor is closer to the ground. I'm not sure what to do to get a "good" count again. Last week I placed the 10/20/40m endfed antenna outside for part of the day and noticed that setup also influences the lightning detector in the shed. Raising the end of the antenna helped a bit, I noticed I can use the back gate of our house as the low end of the antenna.
2015-07-29 Finally a nearby thunderstorm 1 year ago
Finally a thunderstorm passed our house today, and it got counted on the lightning strike detector! The downside is that switching the light on in the shed a few times causes more 'hits'.
Lightning strikes counted today
2015-07-05 Moving the lightning detector to the shed and testing 1 year ago
I thought of this ages ago: Moving the lightning strike detector to the shed but only today got around to it because we had some serious chances of a thunderstorm earlier today which showed up on the lightning strike detector but the graph was completely screwed up again after I tried some psk31 digital mode transmissions on the 20 meter amateur band (14.000 to 14.250 MHz for me). So now it is in the shed. Moving it to a lower position does mean I will not get readings for thunderstorms as far away as I used to but I'd rather have usable readings at this moment. First tests with transmitting psk31/psk63 on 20 the meter amateur band after I changed it look like it doesn't count the transmissions anymore. Now to wait for the next good thunderstorm to see how that gets counted. Some blips are showing up. Update 2015-07-14: The first result seems to be that using the lights in the shed (tubelights with starters) shows up clearly. Using the radio still has no effect. I now await the first thunderstorm for more results. Update 2015-07-28: No thunderstorm has been reported by the KNMI weather institute thunderstorm archive within a short distance of my sensor. I guess the maximum range is quite limited now.
The last year in counted lightning strikes, showing clearly that I got active on 20meter psk31 in October 2014. The 'blips' before that are real thunderstorms.
2014-11-16 A wet roof and radio transmissions from the attic don't get along 2 years ago
The current rainy weather is reasonably deadly for any transmitting, given the report from Digital mode reception maps at pskreporter.info which states:Monitoring PD4KH (last heard 20 hrs ago).while I am quite sure I transmitted PSK31 CQs and answers more recently than that and the 10 meter band being open according to the same site. The attic dipole is right under the roof so any rain making the roof tiles wet is probably dampening the radio signals. This may get interesting when there is snow on the roof. I imagine some raised eyebrows when there is an antenna shaped hole in the snow on the roof.
2014-07-19 (#) 2 years ago
The heat is on: the Weather station Utrecht Overvecht in our backyard is showing a temperature of 36.0 °C at the moment. Compared to official observations like the ones published at Actuele waarnemingen KNMI the temperature at my weather station is a few degrees too high. This can be explained by the fact that the sensor in the backyard is in an area between houses and the fact that we live in an area with a definite 'urban heat island' where temperatures are higher than the surrounding open country.
2014-04-07 Trying to hear amateur satellites and the right way to make contacts 2 years ago
Trying to hear and work the SO-50 satellite as PD4KH portable has one downside: certain types of weather don't agree. The first pass this evening was really nice, straight overhead. But closer to earth there were serious rainclouds overhead causing a downpour so I opted to skip that one. A pass later in the evening started dry so I went outside. During the pass it started to rain again a bit so I had to dry my laptop after I was done! It was a low West-North pass and those are harder to follow from our house. But I did hear some voices and I think I understood at least one callsign, but checking the live oscar satellite status page shows no callsign matching what I think I heard. Update 2014-04-08: Another nicely timed West-North pass, without rain this time. I heard some interference, including someone who decided that whistling at the satellite was a good idea. Probably taken directly from the "what NOT to do with amateur satellites" handbook. The pages maintained by Mike Rupprecht DK3WN about amateur satellites have some realaudio samples of good and bad use of the amateur satellites: SaudiSat 41, 42, 50 - Mike Rupprecht - Amateurfunk Betrieb über FM Satelliten - Mike Rupprecht - Amateurfunk I don't agree with the quoted statement by LA2QAA in the last article of being proud of never using the "easy" FM amateur satellites. A more positive approach is needed in my opinion. One "mental" switch I have a problem with: with the squelch completely open I hear noise when I'm either not listening to the satellite or the satellite is not in use by another amateur. With listening to "earth" FM repeaters at normal squelch settings I'm used to noise meaning that someone is trying to use the repeater but failing. This means pressing the transmit button when hearing noise on the satellite is a bit "unnatural" to me.
2013-11-05 (#) 3 years ago
Vandaag met een wat langere/betere antenne geprobeerd over repeater PI2NOS heen te komen. Geen echt succes, de andere partij meldde zoveel ruis en flutter dat het niet echt verstaanbaar. Ik wil graag verbindingen kunnen maken vanaf de ligfiets, maar het blijft lastig. Nu was een extra factor dat het regende waardoor mijn natte regenjas vast nog meer demping veroorzaakte. Daarnaast hangt de 4W (UHF) portofoon aan de riem ook maar ongeveer 1 meter boven het aardoppervlak en niet altijd even netjes vertikaal. Update 2013-11-06: Ondertussen er eens aan gerekend met Radio Mobile Online. Dat is de online versie van 'Radio Mobile', software om radio dekking en verbindings planning te doen. Daar komt er uit dat in theorie ik prima binnen zou moeten komen op PI2NOS. Maar ik heb het idee dat de 'landcover' data niet compleet is, ik zie op de verbinding tussen ons huis en PI3UTR niet dat er wat hoge gebouwen dichtbij ons huis staan die zeker problemen geven. Erg leuk om aan dekking te rekenen hiermee, maar ik zou het nog leuker vinden als het werkte!
2013-01-14 (#) 4 years ago
This morning it was cold on my recumbent bicycle, frost formed on the speedometer. Brrrr!
2012-08-08 (#) 4 years ago
A rainy day makes the ADSL downstream speed interesting...
2012-08-07 (#) 4 years ago
Rainy weather, lower bandwidth:Available Bandwidth Cells/s Kbit/s Downstream : 18596 7885 Upstream : 2426 1029And hickups.
2012-04-13 (#) 4 years ago
Fresh cloudy skies on http://webcam.idefix.net/. It's back, someone was kind enough to lend me some room in his window giving a nice view in a north-easterly direction.
2012-02-08 (#) 4 years ago
Snow is always nice on satellite images, so I had a look in the NASA rapid response system for recent images of our snow-covered country. This one is a winner! Click for high resolution.
The Netherlands, Snow-cover 20120206 1105 UTC
Image credit: NASA/GSFC, MODIS Rapid Response
2012-02-07 (#) 4 years ago
Het Weerstation Utrecht Overvecht heeft nu ook Nederlands geleerd. Voorlopig voor de waarnemingen en de webpagina, misschien in een later stadium ook voor de teksten rond de gegenereerde grafieken.
2012-02-07 (#) 4 years ago
Low temperatures in the Netherlands: the Weather station Utrecht Overvecht is measuring temperatures below zero at the moment. Which all goes fine, the software deals with it nicely.
2011-12-15 (#) 5 years ago
Tried a few DVB-T service scans today in the rainy weather and unsurprisingly rain degrades the UHF reception. Even the Digitenne Flevoland multiplex wasn't always error-free enough to show in the scan. DVB-T service scan for 2011-12-15.
2011-10-06 (#) 5 years ago
Updated the Weather station Utrecht Overvecht page to give the latest measurements. In the background it changed from an rrdcgi page to a perl page so I could easily add those measurements.
2011-09-01 (#) 5 years ago
Great pictures and videos of lightning striking (or moving up from ..) transmitter towers and other tall structures. Showing that lightning can strike twice in the same spot in the same thunderstorm. Or even 11 times in the same thunderstorm striking the WKYT / WTVQ towers in Lexington, Kentucky. Great stuff with lots of attention to detail and great stories behind the making of the pictures and videos by Dan Robinson. Posted on the tx-list in a discussion about lightning safety in transmitter towers.
2011-05-25 (#) 5 years agoOlder news items for tag weather ⇒
Luck in Iceland with research into the ash plume from Grímsvötn volcano:The IMO has a mobile weather radar on loan from the Italian Civil Response Authorities. When Grimsvötn erupted it was placed near the village Kirkjubæjarklaustur, about 80 km from the volcano. The weather radar is used to monitor changes in the height of the volcanic plume, but those are indicative of the strength of the eruption.The mobile weather radar helps understand the size and direction of the ash plume, without having to get too close.
Source: Update on volcanic activity in Grímsvötn - Iceland Meteorological Office. I am a fan of Iceland, I want to go visit it again some day.