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Showing posts from July, 2024

Unschooling and Python || wget, tar -xvzf and for loops

 Last night was a shorter run at things in general because KO6BTY, (the 13 year old known as Diaze here), and I got a later start. We spent what felt like forever, but what was actually only 12 minutes trying to share files from the 'usual' file side of the kid's Chromebook with the Linux side using file folders and whatnot. Nothing worked. For whatever reason, the Linux folders weren't visible in the machine's 'My Files' app. Sharing folders led to the machine basically hanging. Then! Then, we handled the issue like a couple of programmers, and instead of downloading in one system and trying to copy to anther, Diaze just ran the following from her Linux terminal wget https://data.cosmic.ucar.edu/gnss-ro/cosmic2/provisional/spaceWeather/level2/2024/203/ionPrf_prov1_2024_203.tar.gz That was snazzy! It just brought the file right in because, well, command line interface tools are just... snazzy.  Having a chat record of our work together is also really helpful

Unschooling and Learning Python

 KO6BTY and I are making another run through Python. Diaze has learned a bit of Python in the past when she set up our QSO mapping app to pull in pertinent ionosonde data from the Digisonde ionosondes. Now, we're working with Python again to analyze data not from ground-bound ionosondes, but from the COSMIC2 constellation of satellits that provide ionospheric data includihng electron density profiles. That was the intro, and the application, but this post is more about how to informallly teach Python. What will work, and what won't? With unschooling, a lot of learning is initiated by something called strewing . Strewing as it's comonly defiined is, essentially, keeping things a little cluttered around the house. It's leaving reading material, projects, web sites, and so on, out where everyone in the house, including and especially the kids, can see them. I've widened the definition to include our entire indoor and outdoor lives, and the city and world at large . For

Reading and Perspectives: netCDF and Databases

I've been referred to a lot of indie web blogs of late, and it's paying off quite nicely for me Here's the latest example. Simon Willison--co-creator of Django and creator of Datasette--has a blog that led me to Maggie Appleton's site . Once there, I found a very nice, and very pretty primer on databases . Within the primer was a perspective I'd never seen before. There was an emphais, (certainly not the only emphasis, but an emphasis nonetheless), placed on columns, like so: from " A Shelfish Starter Guide to Databases " I, frankly, had never considered coluimns in any way except, as 'fields' that contributed to rows, and that could have conditions placed on them. A column as a whole entity unto itself? I'd never considered such a thing. A few days later though, while studying the netCDF format used by COSMIC2 missions among projects, I suddenly needed that column perspective, and I had it! netCDF files from COSMIC2 are very much arranged a

Another Cool Tool from Simon Willison via Claude

 Image quality compare from Simon Willison and Claude! One of the many aspects of Simon Willison's blog that I've enjoyed is the set of posts about coding tools with LLMs (AIs.) The latest one was handier than most for me. It takes an image and downsizes more and more, presenting the different version on a web page so you can judge which one will work best for your website's view while cutting down on the amount of data your web site serves for that image. So, here's the faster version of this blog's occasional header Chosen from a variety of options: You might wonder if I went meta on this and used the tool to reduce the size of the screenshot of the tool, and I aboslutely did!  Cool stuff!

POTA from Gloria Dei Church National Historic Place US-10802

Nine year-old Tawnse and I got half-way to activating the park before the ML-300 Bluetooth transmitter gave up the ghost. I knew I forgot to charge something.  Tawnse was so entranced with the walled Philadelphia park she thought we should have stayed the extra half hour we would have probably needed to activate it.  What led Tawnse to this scheduling priority decision? Turns out the park doubles  as the neighborhood dog park. There's only one way in or out though a small and, of course, historic  cemetery. By the time the pups got to the wander-around-unleashed bit we were in they were far to transfixed to try to leave. Turns out two of the pups were aspiring radio engineers to boot .We ’ ll get to that. Because our antenna was low, propagation wasn't great on 20m at 15:30 UTC on the East Coast next to an interstate in Philadelphia. Even so right after I self-spotted a fellow ham immediately called in from South Dakota. After that, the QSOs came in every five minutes or so on

Locally Sourced Data and Software

 The gang and I are very lucky to live in a San Francisco neighborhood where we have markets, a family owned pharmacy, and family-owned restaurants, coffee shops, and delis all about a ten block walk from the house. Here’s the haul from our Farmers Market that we walk to along with our local butcher shop and dim sum bakery a few weeks ago. Consequently when I saw a mention of local-first software ,[ via ] I was intrigued. (As a side note, the presenter, Maggie Appleton, at one point in the not to distant past , worked with Elicit, a research paper summarizing AI startup with an office in Oakland, so kind of surprisingly local, but I digress.)  It turns out that local-first development advocates for keeping the data for an app offline, i.e. keeping the data with the person who created or is using that data by default. But, what happens to collaboration? Well, the local, offline data is synched to the cloud when a connection is available allowing for collaboration while also creating

Project TouCans Lab Notebook: Getting Rid of the Noise

 I finally landed at a quiet tape vs. noise  configuration for TouCans on Saturday afternoon. Here’s how. In the picture above, the wires circled in green include the + and - power wire, (white and red respectively), and the keyer wire, (also red.) When I taped the bundle of wires including the single turn coil shown in the white wire to the side of the can, the noise from the power supply went away. I was left with only noise from the radio, (the kind I want), and a gentle hum from the power supply because it had switched into buck converter mode to step its voltage up to the required 15V! The helicoptering from the Pico-W was also almost gone. In other parts of the project, the Pico-W has started burning through pairs of AA batteries rather quickly.

POTA from Pope John Paul II Park in Quincy, MA US-8422

 Slowly but surely, KO6BTY, Tawnse and I are making our way back to the West Coast. Last night, we stopped in Quincy, MA for the flight we thought we were going to take this morning... It looks like we are gonna call the East Coast our headquarters for a few more days, This has however, opened up POTA opportunities. Last night, I had the chance to activate Saint Pope John Paul II Park, US-8422 , in Boston just across the Neponset River from where were staying in Quincy. The park is relatively new. It was opened to the public in 2001 and commemorates the Pope’s visit to Boston in 1979. It was constructed on the site of a landfill and a drive-in movie theatre. Setting up near the river turned out to be a wash. The park is arranged so there is fairly thick vegetation between park denizens and the river. I did, however get to set up about 10 yards back from the river in a pleasant little copse of trees.  First though, I had to get the spools of twine up into the trees. For that, I was hap

LobsterCon Wrap Up

  The weather finally started to cool down a bit the day before LosterCon started. We had plenty of sun, but it wasn’t baking hot.  The campground, where LobsterCon was held, Thomas Point Beach and Campground, was clean and well appointed, maybe too clean. There were no rocks laying about that would fit in the end of the tarred twine spools, so we wound up launching the antenna using pine cone stoppers. We had plenty of nice, flat ground for our two tents, and managed to get Project TouCans about 20 ft up between a pair of pine trees. TouCans made two QSOs during LobstserCon, but the really nice part was all the in-person QSOs getting to hang out with everyone.  KO6BTY and Tawnse diagrammed TouCans on the nearby beach the first evening. Later that night, the rig reached KF9VV in Wisconsin.  The night after that, I made a short DX QSO with M7LLS. Then, we had lobster! So much lobster! During the flea market, we got to check out new and old kits from W1REX of QRPMe . TouCans is defi

TouCans Lab Book: It was an Inductor!

TouCans is back up and running! The culprit did in fact lie in the path between the power supply and ground in the PA chain. I didn’t see it coming though. Here’s the problem: There was a cold solder joint on one side of the inductor. When KO6BTY and I measured the resistance across the inductor, it was infinite. When we remarked about this, 9 year-old Tawnse immediately said, that’s not what inductors are supposed to do. And yeah, she’ right. They’ supposed to conduct at DC. Anyway, a few minutes later, we’d gone from this Notice the magnet wire tint to the two wires whose solder joints are completely in the picture? To this      Which, in turn, led to this later that evening. The moral of the story for me? Always check the two terminal component first because they’re the easiest to fix.     

LobsterCon Travelog: Philadelphia

 We headed from Boston down to Philadelphia. Yeah, I know, that's no way to get to Maine, but when my partner and I were doing grad studies at Brookhaven on Long Island, Phillie was one of our favorite hangouts, so here we are! With all the mapping Cesium has enabled of late, we were pretty tickled to get to visit their headquarters here in town. We got to demo our mapping tool that works with Datasette, and then got to ask questions about Cesium as well. Turns out the small object we frequently notice on the horizon is the Moon! From there, we headed to Isgro near Christian and 10th. Armed with delicious pastries, we wandered up and down 9th St. checking all the other delicious things! A few hours later, Paesano's became our favorite place in town for pasta. We've had lunch there twice now, and just, oh my gosh, the food is so good! Another day, a little further down 9th St., we found $5 cooked crabs and demolished them! I didn't understand why they asked if we wanted

LobsterCon Travelog

We're on the East Coast! KO6BTY, myself, and the 9 year-old, (known on the internets as Tawnse), flew out to Boston from San Francisco yesterday. We walked out of the airport to the ferry terminal! That's so cool! You can walk to a ferry from the airport. But do you know what we did then? We didn't take a ferry, we took a water taxi to a different ferry terminal! So many cool things already! Here's the view from the water taxi. We landed at Rowes Wharf which seems to be one of the fanciest wharf's in Boston, so.. yeah. From there we caught the ferry southeast to Hingham  and from there made it to our camp site at Wompatuck State Park. We're now making our war around via public transit taking the T back in to Boston South Station to catch a train from South Station into Philadelphia. Meanwhile! KO6BTY and I have had Cesium maps built into our QSO log for a few months now—ever since the day Simon Wilison nonchalantly pointed out that Datasette queries are URLs i

Lab Notebook: The Rockmite isn't Transmitting

 KO6BTY took over debug implementation last night. She wired the RF out from the Rockmite directly to Project TouCans antenna out and... Nothing. Looking at the schematic , that leaves a few choices for what's going on. My favorite for the moment, because it's easy, and because the part is actually very bent, is the T/R switch transistor: The transistor is a 2N7000  MOSFET. Wikipedia lists its maximum current as 200 mA and I can see where we could have exceed that when the Rockmite was shaking loose in TouCans (several of the nylon spacers sheered after a fall.) Also, keep in mind that the power bump has more current traveling through this part of the circuit in any event. After that, we'll be looking at whether or not the oscillator is still oscillating. But actually! Good news! If the oscillator weren't oscillating, the receive branch also wouldn't work, and it most certainly is working!

Lab Notebook: TouCans Debug: It Wasn't the RockMite PA Transistor

Since we returned from camping, Project TouCans has been pretty much off the air. We still have receive, a keyer, and a sidetone, but the rig just isn't transmitting. Last week I thought the issue might be the output transistor of the RockMite. It is not. I removed the original transistor, replaced it with a new one, and to no avail! Here's the before And after There was no change in the operation of the rig. No signals were spotted by the RBN or either of the Utah or Half Moon Bay SDRs.