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Showing posts with the label geography

rm-rbn-history New Feature: RBN vs QSO Icons

Yet another new feature has been added to the ham radio RBN spot/QSO mapping project. I'm really starting to like the way the maps look these days. The latest new feature places 'R' icons at reverse beacon network stations and 'radio station' icons at the sites of QSOs so the two different kinds of activity can be easily distinguished. You can read more about it at github in the associated issue .

New spot and log mapper features: Transparent RBN and Color Coded Signal Strength

It was difficult to tell the paths from KD0FNR's 20 meter Rockmite to Reverse Beaccon Network spotting stations, and actual QSOs. I started by labeling the paths, and then took a final step to make the spotting paths transparent and immediately evident. The first new set of features includes adding descriptive labels to each path including the callsign of the receiving station as well as the time and date the call was received. The labels appear when the path is clicked. If you'd like to try any of these features out, you can load the kml map at  https://drive.google.com/file/d/1dNkpzdjHaQqMRrulhPYHprZb9OJHbSup/view?usp=sharing into Google Earth on the web. I also wanted a way to determine the relative strength of signals at a glance. I developed a color coding scheme for the paths based on ROYGBIV with brown added in a 0 for 'unknown'. The color coding is  Color S value Brown 1 or uknown Red 2 Orange 3 Yellow 4 Green 5 Blue 6 Indigo 7 Vi...

New Distance Record for the KD0FNR Rockmite and the Google Maps Geometry Library

 The KD0FNR Rockmite transmitted it's furthest disnce ever last night. It was spotted by an SDR in Newton, NH, W1NT. The heading to the station, interestingly, lines up with the previous record in Maui. I used the maps API to find out how straight the line was. The previous record, (set almost daily), is off to the West in Maui .  Here's the two spots on the same map. For those of who might be wondering if the Boston, NH and the Maui station are on a perfectly straight line, I wondered the same thing. They're not. They miss by about 4 degrees. How do I know? Turns out Google Maps has an API for that. ( and a demo ).  Using the demo, I was able to get the two headings and then add them to determine how close to a straight line (180 degrees it actually is). OK, let's look at the headings. To Newton, NH, we have To Maui we have Adding the two headings we get 176.0069 degrees. So not quite on the exact same line to the antenna, but close. I also wondered if my imprecision a...

Mount Tamalpais Parks on the Air Activation by KD0FNR

 There'll be more posts on this over the next few days, just some early thoughts on a really fun day playing ham radio at Mt. Tamalpais.  The antenna wound up fairly high at our final location near the campsite. I thought there might be issues with the high winds, but aside from being generally cold outside the tent, everything went great. Earlier in the day, with a much lower antenna we demonstrated more of what I started to see at Baylor Pass . The radio was setup in a canyon along Bootjack Trail. I surmised we'd only reach stations pretty much directly south of us, and sure enough : and in more detail the one station, K6FOD, that spotted us in our admittedly very short time transmitting was lined up along the canyon.

Things I Learned Today: Google Print, Rain Drops, and Antenna Testing

 Let's start with the good news: the little desktop Rockmite made a QSO with K7ZAD in Farmington, Utah today.  While this was happening though, the reverse beacon netork detected absolutely nothing . I learned that the RBN is A tool for testing antenna changes, but kinda obviously, not the ONLY tool. I also learned about rain! I'd read that rain clouds do not attenuate HF signals. I had my doubts since I hadn't been able to make QSOs or even hear many other stations during rain storms. Turns out though, as explained in HRWB 168 - Audio for Digital Modes with Michael Black , rain drops make static, so effectively the noise floor that I'm hearing signals against is increased. And finally, I tried printing the QSL card templates via Google Docs rather than Microsoft Word, and it did not work.. Google Docs is limited in the size of pages it knows about, and the USPS double postcard is not one of Docs' known sizes. Apparently there is a plugin that will allow this, but ...

Clouds Eats Mountain! Film at 7

I came across this picture of Sierra Blanca near Ruidoso, NM last night.  The peak of Sierra Blanca sits at 11,981 feet, above sea level more than 4,000 feet above Alto, NM where the picture was taken.  As a kid, growing up in Ruidoso, we'd say things like, "Wow, that cloud just hunkered down on top of the mountain." just assuming the cloud had come from somewhere else.  Looking at how the cloud above seemed to be literally streaming into the peak, I wondered if there was some kind of sciencey correlation between clouds and mountains.  I found the answer in an article from the February, 1901 issue of "The School World" by George Chisholm [1] that explained mountains actually help to form clouds, not attract them from afar. Here's how it works.  Wind carries air saturated with water vapor into the mountain where it is forced up the slope.  As the air rises it expands due the lower air pressure, and as it expands, it becomes colder. ...

Martinique on 14 and 10 MHz

Click image above to go to logbook entries FM5Ld from Martinique was spotted today. Cool stuff about Martinique: It's an overseas region of France. It's part of an island arc along the Puerto Rico Trench that is the boundary between the Caribbean Sean and the Atlantic Ocean.