Copasetic Flow

  After contacting Alaska from San Francisco on 14.0574 MHz with 5 watts power delivered via a 1/4 wave vertical antenna through an apartment highrise last week, I started building models of HF propagation around buildings. This culminated in several new tools that I'll be discussing in more depths in future posts and the propagation map you can interact with towards the bottom of the page. What's in the Map Radio Contact Paths The map shows the QSOs (radio contacts) I made from the park on the top of One Maritime Plaza . Each contact is mapped out by a solid line running along the ground as well as a likely path the high frequency radio signal took as it bounced off the ionosphere on its way to the receiving station. I've talked about mapping F2 bounces before .  Fun F2 paths near a moutain outside El Paso, TX The paths in the map below use the maximum F2 layer height of the ionosphere at the time of the contact as it was reported by NOAA Glotec data . If you'd like t...

  Do LLMs always generate the correct set of code given their inputs? Nope. You can use the same LLM to verifiy its own outputs if we're clever about it though. Here's an example from a recent HF interference model I asked GPT-5 to build for me after a Parks on the Air (POTA) ham radio outing in downtown San Francisco.  My first QSO perched on the edge of One Maritime Plaza was with AL7KC. That's not too surprising, I pretty regularly communicate with AL7KC. Except. It was kinda surprising because there was a skyscraper—Gateway Vista West—directly across the street between me and Alaska and about twenty-three meters away. View from the QTH That one little skyscraper led to a lot of fun HF propagation analysis using GPT-5. I described the area around my transmit site at One Maritime Plaza to GPT-5. I got some really interesting interference patterns based on the surrou...

 I found a new operating location in downtown San Francisco that combines the Butterfield National Historic Trail and the Pony Express National Historic Trail and was so much fun! To be clear, I don't know if I'll ever activate either park from this spot, but wow, the architecture! And! Wow! The RF propagation curiousities! I had the TransAmerica Pyramid on one side of me  and the building formerly known as the Alcoa building on the other My operating position was from the Maritime Plaza, an elevated park smack in the middle of the Embarcadero. Take a look at the Cesium Map using Google PhotoRealistic tiles below to get a good feel for the whole area. (I'll keep you posted, but for the moment, you'll have to dial in the map yourself, I haven't had time to standardize my saved view code to all of my maps yet. I wound up making a whole series of videos just getting to the site. You can see them in the playlist below. Here's the cool thing that got me back to my r...

 Just a brief description of how I capture audio recordings during Project TouCans outings. First, where's the audio coming from? Project TouCans of course.  It's frequently in the air, embedded in its dipole antenna, so about a year and a half ago, we started piping audio to the round via Bluetooth. Specifically, the audio out from the RockMite feeds this Bluetooth transceiver, a 1Mii Bluetooth 5.3 Transmitter Receiver for TV to Wireless Headphones For the recording/receiving rig, I use a different Bluetooh reciver, an Alura . It's the only Bluetooth receiver I could find  that would receive the 1Mii. From there, I use a stereo connector splitter. One side goes to my Sony voice recorder microphone input. The recorder is fine with the fact that I don't have an attenuater in the line.  The other side of the splitter feeds my Bose Ultra QC noise cancelling headphones. Do be honest, I have those for work, not for palling radios. The whole system, over time, has ...

Extra Class Practice Exam (Stacked Bars with Toggle Groups) Extra Class Practice Exam Get ready for the FCC Extra Class license exam with this free online ham radio practice test. Our interactive exam tool uses the official FCC Element 4 Question Pool (valid July 2024–2028) and automatically tracks your performance. See your score history, review stacked bar charts of correct vs wrong answers by subelement, and drill down into specific group stats with a single click. This is the first practice run of the free online ham radio practice exams. I fully expect it to be a bit buggy. Please leave any suggestions or bug descriptions in the comments. Exam scores and statistics will be stored in the URL when you click 'New exam/Save Scores' after you complete an exam. To get back to your scores, you should be able to use the histsory feature in your browser, or if you'd rather, copy the link somewhere to put into a browser later. Important Note: To save your s...

 This week I spent some time tightening up the workflow for comparing F2 ionospheric data across different POTA outings. It turns out documentation really does matter. By writing things down, I’ve not only made the manual process clearer but also pushed the automated flow forward. With GPT-5’s help on documenting proton and electron flux plots, and my own notes on numeric F2 graphs along QSO paths, the project is steadily becoming easier to repeat and share. I put in a little bit of time working on being able to easily compare F2 data for different POTA outings this morning. It turns out documentation really does matter, so I've been focusing a bit more on it. I have a number of tools that allowed me to pull in F2 data quickly. This week I've been trying to spend time pulling them into an automated flow. As I've implemented this flow, I've discovered that I haven't taken the time to document the tools I've already built.  I asked GPT5 to document the solar prot...

Getting back to that Argentina call. One thing KO6BTY pointed out was that the FoF2 numbers didn't look normal. She was correct to an extent. They definitely didn't look like they did a few  months ago. Early morning UTC time, the critical frequency numbers looked like this Critical Frequency at time of QSO to LW2DO in Argentina A few months ago, in February though, they looked like this at roughly the same time of day. Critical Frequency map in February of 2025 a few hours earlier in the day Patterns in the F2 Layer If you're curious how she spotted the difference quickly, we've identified features that are usually on the map, the 'goose', and the 'face.' The Goose The Goose is characterized in profile with it's beak usually outlined in blue. It's circled by the green line above. The Face The Face is perhaps a bit more obvious. Again, it's circled in green. The two low critical frquency zones, (black regions), form the eyes. The black spot ...

  While analyzing the skip path of a a 5-watt QSO I made last week from the San Francisco to Argentina with Project TouCans, I stumbled across a set of NOAA resources that completely changed how I look at ionospheric conditions. From real-time aurora dashboards to animated MUF forecasts and electron flux data, these tools offer hams powerful insights into propagation—and some surprises along the way. I made a grey line QSO from the campus of City College San Francisco to Argentina with our 5-watt Project TouCans rig last week. Last night, KO6BTY and I found ourselves deep in the rabbit hole of ionospheric conditions. What started as curiosity about the Kp index and whether aurora activity might have influenced the QSO's skip path, led us to discover some powerful NOAA resources. From aurora dashboards and global ionosphere forecasts to animated MUF predictions and GOES electron flux data, these tools give ham radio operators new ways to understand HF propagation, F2 layer behavior...