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Showing posts from May, 2025

Back to Agent Sonya and Her Vacuum Tube Homebrew Rig

 How difficult is it to build a single tube ham transmitter? Honestly, I don't know because I haven't tried. The gang and I are out camping this week and thoroughly enjoyed listening to the latest episode of the Soldersmoke podcast as we were out exploring the area around Baker, NV. In the podcast, (episode 260), Agent Sonya  came up again. (Here's the Soldersmoke blog post for the podcast.) I have to say, I'm still a believer. Maybe it's time to put my money where my mouth is though. So, this week, the kids and I will be researching: The article in the 1936 radio handbook on page 111. Whether or not we can still get our hands on a functioning 6C6 tube and socket. Can we find a crystal that fits into a socket like the ones advertised in the back of the handbook? Can we maybe bring the plate voltage 6A6—aka a 53 tube—down to something more manageable than 450 Volts?  How does the circuit function and how does it depend on plate voltage anyway? What sort of oscilla...

Mt. Moriah US-9269 Activation!

 I was the second person to activate US-9269 Mt. Moriah BLM National Conservation Area yesterday! The gang and I are out on our annual campign trip to Baker, NV and the environs surrounding Great Basin National Park. We drove to our trailhead using the Hatch Rock Mine access road. The mine extracts quartzite for use in building. The entire wilderness area where the gang and I hiked had frequent quartzite deposits.  That second photo shows the top of a quartzite outcropping that wound up being about four stories high when viewed from below. I realized this once I got to the bottom of the outcrop as I descended the ridge I was on after the POTA activation. Google had this to say about the stone: Mt. Moriah Flagstone is a premium metamorphic quartzite sourced from the pristine Snake Mountain Range on the Nevada-Utah border. This exquisite natural stone showcases a harmonious blend of slate gray, soft mauve, and warm tawny chestnut tones, creating an aura of delicate refinem...

New! Split Screen Project TouCans Video QSLs

 I've been casting about trying to find the format for Project TouCans video QSLs I liked the best, and I've finally got it! Today, in the Mt. Moriah BLM National Conservation Area, (US-9692), I learned how to do split screen while also recording the screen, and I'm kind of in love with the way these look! In one panel, you can see the controls for Project TouCans. Over the audio, you can hear the QSO and my commentary as I work. In the other panel, you can see the view out the front of back of the phone which is kinda gorgeous on Mt. Moriah! It's just like Project TouCans. It mixes really old tech—the rig—with brand new tech—split screen phones, html/JavaScript control panels, embedded controllers; the last two things at least partially built by an LLM at this point—and looks kinda awesome... to me, anyway! Here's the first QSL. It doesn't have the polish of the ones I make at home—the gang and I are camping near Great Basin National Park—but I love the format...

Today I Learned: One UI Closes WebSocket Connections on Task Switch from Chrome Browser

 During yesterday's POTA activations, I kept losing my control panel connection to Project TouCans. I restarted the rig's Pico-W several times to re-establish the connection before it occurred to me to think through the symptoms which were: Productively using the control panel to key the rig Switch to any other app on the phone besides the Chrome browser Return to control panel on Chrome browser and the connection is gone. On my implementation, the control panel's On button first opens a WebSocket to Project TouCans' Pico-W. As an experiment, rather than power cycling the Pico-W, I simply hit the 'On' button again even though the rig was already on. Sure enough, that did it. The connection was back up and running. I asked ChatGPT what might have caused this. I mentioned that the phone, as Samsung Galaxy 23 had forced an update of One UI. The answer that came back was that versions of One UI newer than 6, (I'm on 7 now), do indeed cut socket connections when...

Video QSL Card that Explains as It Goes N4GO de KD0FNR at US-0575, San Francisco Maritime National Historic Park

 I haven't tried this before, but it was a lot of fun. On this video QSL, I explained what was going on with the rig, (Project TouCans), and the Morse code within the QSO with N4GO in words on the video as the QSO was in progress. New video style for N4GO de KD0FNR The map below is for the entire POTA activation. It shows RBN spots as 'glowing' lines this time and QSOs as solid lines, (like always.) You can click on any of the signal paths to get more inforatmion about it. You can click the play button on the lower lefthand control panel to animate the map so you can see the QSOs as they occurred. QSO/RBN  Map for the 2025-05-20 KD0FNR US-0757 POTA Activation

Two Ops, Two Control Panels, One Rig, Project TouCans as a Networked Resource

 We moved to a web based control panel for Project TouCans a few months back. It's worked really well. Changing the network model of the system to one where TouCans uses a smart phone for network resources as a client even unexpectedly reduced the audio noise in the rig. Even though the control of the rig is now done via browser, KO6BTY and I hadn't tried to control the rig from more than one smart phone until our recent US-4578 POTA. Before I go any further, here's a brief introduction to the control panel. On a POTA activation last week, I set up the rig to talk to my smartphone via a mobile hotspot. KO6BTY then set up her smart phone to use my smart phone as as Wi-Fi source. The rig was immediately available to her at the same internet address! TouCans has almost moved into the cloud! For now, it's moved into the WLAN! The control panel doesn't have the concept of multiple users yet, so Hamie and I had to adjust keying speeds when each of us took control over fr...

Today I Learned: Default CZML "great cirlce" aerial paths can be made straight line with "arcType: NONE

 I spent a little bit of time doing math debug this weekend, but in the end it turned out the QSO mapping app had a visualization issue, not a math issue. It was fun to get to look at the math for calculating the apparent launch angle of our antenna using F2 height data and rx/tx station locations. I wouldn't have thought to do the review except I had data that didn't match the maps I was getting back. According to the launch ange calculations made by our, (mine and KO6BTY's), QSO mapping app, the launch angle for the signal from our QTH was 0.00227 degrees. The map however, showed the path of the signal soaring over the very nearby Bay Bridge. The angle shown is much larger than 0.00227 degrees. Here's a picture of the nearby Bay Bridge with our antenna in the foreground. After completely reviewing the underlying math, it occurred to me that CZML likes to make lines that follow great circles. To make something that approximated a circle out of a path with a very low ...

Project TouCans Lab Book: Varactors

 Just a few notes on the varactor that's providing the FSK on the Rockmite and a few more notes on the FSK circut itself. This page will continue to evolve and is related to the slow moving project to try out teletype with Project TouCans . To communicate in most of the 20 meter RTTY band, the rig needs to have a 175 Hz FSK, rather than 500 to 700 Hz. I'm woroking on understanding the FSK circuit to see if it can be modified to give the desired shift. Short conjecture: I suspect/hope I can place a small variable capacitor around the varactor to bring the frequeqncy shift into the range that will work. The RockMite achieves frequency shift with its Colpitts oscilator via the following circuit from the manual and I'm just not sure how this works out. When Q2 closes, it looks like there should be a short to ground. The Zener, D5 with its 4.7 V reverse voltage, is immediately gone. Using the capacitance chart below, it looks like we gor from 100 pF from the varactor ot on the ...

Can a Rockmite RTTY? Rapid Prototyping with ChatGPT

 Can a RockMite send RTTY without a modification? Maybe. There are are two reasons it might not be able to. First, the keyer might not quite work the way I'd like for it to. What I need the keyer to do is to allow me to hold the key down in straight key mode while changing the FSK frequency of the rig by tapping the programming button. The second reason is that the frequency shift on RockMite's is between 500 and 700 Hz. Meanwhile, most rigs on the ham bands use a 45.5 baud rate with a 170 Hz separation. However, the German weather teletypes transmit at 50 baud with a separation fo 500 Hz, so there's a precedent for recievers that could decode RockMite RTTY if a RockMite could RTTY. The nice thing—the thing that got me thinking about teletype at all—is that RockMites have a built in, controllable FSK. Consequently, I asked ChatGPT to write microPython code to pull the FSK line on the RockMite. What I hadn't thought through was that KO6BTY, or I still needed to add a re...

Adding Elevation Control to QSO Maps with ChatGPT and Cesium

When making our QSO skip maps one of the issues we encounter is that the lines from our station to the F2 layer don't always start right at the ground. This seems to be an artifact of CZML and the fact that the Earth is not a sphere, but rather an ellipsoid, and even then, there are all those hills and mountains. The initial QSOs can wind mapped as up coming from underground: or, they can wind up starting from above the surface of the Earth In any event, it's been necessary with each map to adjust the elevation height of our station. I've yet to find a parameter to set in a czml that makes the starting point always be on the ground. "clampToGround" works for polylines that are always on the ground, but not polylines whose next point has an altitude greater than zero as the ground station to F2 layer polylines do. I added a feature into the JavaScript mapping application this week that allows me to adjust the height of all of the QSO's starting points at...

Why So Many People Report Seeing UFOs in New Mexico

 The Soldersmoke blog referenced a post about a really cool missile tracking helical antenna.  Soldersmoke reference to EI7GL's writeup of the antenna. The specificity of the plaque down to the Marker Number reminded that the gang, my partner, and I had visited the White Sands Missile Range outdoor missile museum back in 2017 . Glancing through my pictures to see if we'd taken a look at the antenna, I came across this doozy which had this plaque on display in front of it I'm just saying here: when you have to start out with the sentence, "Not a flying saucer" and then follow up later with "action was initiated to start the vehicle spinning for stability" and then offhandedly mention that the vehicle traveled at 1.2 times the speed of sound before firing an explosive charge at apogee... ahem... Not a flying saucer indeed, but you know, totally a flying saucer :) Here's the entire plaque text: " Balloon Launched Decelerator Test Vehicle Not a f...

Moving the TouCans Cootie Keyer to WebSockets Also, The Interconnectedness of Unschooling

 The TouCans keyer works much better than it ever has in the past, (apologies if you were on the receiving end of a key down lockup), and it's all due to connections I made while unschooling with the 14, 12, and 10 year old gang of kids here. This story stars when they were 9, 7, and 5 years-old, so strap in :) I've probably written about this before, but here's the rough chain of connections The, then, five year old, known as Tawnse here, and I attend a design exhibit at SFMOMA where She and I find a Foldscope , a simple origami-inspired microscope that's pretty fun, and pretty cheap Tawnse develops an interest in microscopy The gang and I join the San Francisco Microscopy Society The Society is working on archiving their old documents. Daize, (aka K06BTY), and I are working on a book about Mike Gladych where we've accumulated a lot of documents. We attend their archivist committee meeting. I read the list of committee members, and there's a name I recognize, S...

Today I Learned: URL as Local First Data Storage (You Know for Ham Radio License Exam Practice)

 I've read a little bit about 'local data' lately, and I've become fairly excited about the idea. Two of the features of the concept that I like are that your data should be your own, not stuck behind a corporations gated off wall on the internet and that you should have a copy of that data that lives on physical media within arms reach. I won't venture into the second one today except to say that with Google, in particular, somewhat constantly doing away with applications it becomes bored with and Amazon deciding it has and then has not rights to serve movies I 'purchased', having my data in a usable format and in arms reach physically makes more sense than I'd like for it to. Today, I'm going to talk about the first thing, being in control of your own data to use as you see fit. As someone who develops open source apps, there are benefits to everyone beside me holding on to their own data. The biggest one for me being that I don't have to figu...

Turns out the F2 is really high: Finally! QSO Specific F2 Visualization

 OK, so this is just kinda cool! Suppose you're operating near mountains and are curious if your QSOs are hopping over the mountains, or if they're knife edge diffracting after smacking right into the mountain. You'll need to know how high the F2 layer was between your station and the receiving station and you'll need to be able to visulaize the path with respect to the mountain. It's taken a while, but we have that now!  Thanks to the GloTEC data curtesy of the NOAA, we know the F2 heights all over the world at the time of each QSO. We can also map our QSOs on a Cesium map with toplogy. This allows us to start with maps like this: where I wondered on the day of the QSO if TouCans' signal would clear the high way embankment, and found out that yes, yes it did. Check out the interactive map below. It has all the QSOs loaded with their actual F2 skip heights.

Trashcan Portable: Project TouCans POTA at US-3012 Franklin Mountains State Park

 I didn't manage to activate this El Paso, TX adjacent park this time, but the innovative antenna KO6BTY and I prototyped back in December did a pretty good job in kinda lousy band conditions! Then, I had to flee the dust storm and head for Albuquerque to catch a plane the next morning. Project TouCans watches the dust storm roll in with its big brother Park: US-3012 Franklin Mountains State Park near El Paso, TX. As is usual for my trips to New Mexico, my radio ops over the weekend were all car transit. Radio Details: Rig: TouCans and a Stick on the only band it uses right now: 20 meters The radio worked well considering the antenna was taped to a rest area trash can. Propagation in general was bad, but I learned a few ways to make things better with respect to the trash can. The rig does better when the insulated antenna wire is not touching the trash can lid. Go figure. It makes sense, but still. Go figure. Here's a closer view  of how the antenna was mounted, although you...

Today I Learned: Google Geocoding Costs More but ChatGPT Helped Me Fix It

 Google changed their billing scheme for geocoding in March. Previously, all users were given a $200 credit for Google geocoding per month. Google removed the credit and replaced it with 10,000 geocoding calls per month, and my bill went up! I've known for a while that my pytest code is running every time the QSO tracker is automatically kicked off by github, (which is about 4 times per hour.) Those test cases make seven Google geocoding API calls each. As of April, they mattered. Adding up all the calls assuming that my QSO tracker spots me zero times in a month and that I log no QSOs, so just the calls from the test cases, gives: geocodes runs/hour hours days/month geocodes/month 7 4 24 30 20160 which is well over the free limit. I asked ChatGPT to change my action  so that the test cases would only run when Python files in the repo changed. This was NOT vibe coding. I had to ask ChatGPT to fix its own coding errors 3 times, handing it the error message each time. It did i...