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Showing posts with the label ham radio

BART Route To East Bay POTA Sites

 This is the route I take to East Bay to do Parks on the Air activations! (Minus the bicycle.)

A Carbon Fiber Mast Vertical on the 20 Meter Ham Radio Band

  Carbon-fiber masts don’t have to be the villain. For Straight Key Month I ran a quarter-wave 20-meter vertical two ways—first with 12-gauge wire taped to the outside of a Goture carbon-fiber mast, then with 18-gauge magnet wire laced inside the mast. Result: both versions delivered S9 into Utah from downtown San Francisco, and the internal-wire build was far stealthier for city operating. I finally got to do a long term—a few hours—test of the TouCans and a Stick vertical antenna with magnet wire on the inside this week! The interior magnet wire setup worked just as well as the same antenna rigged with 12 gauge wire taped to the outside of the carbon fiber mast did. The rig was S9 into the Utah SDR that morning. Here's a look at the antenna setup and results. There are more text details below the video.. Construction To construct the antenna I removed the brass bottom of the carbon mast, removed the upermost segment, and then inserted 18 guague magnet wire through the...

US-0757 POTA Notes 2026-01-09 US-0757

 An AM broadcast station was loud in my headphones for about two minutes. Then, TouCans mysterious noise cacnellation circuit charged, and the POTA was off and running. According to the POTA website, I haven't activated US-0757 , aka the San Francisco Maritime National Historical Park , in about eight months. It was nice to be back! We'd had about a week's worth of atomspheric river rains, so it was pretty phenomenal to have this view during the activation. The temperature was in the low 60s which was very pleasant. I didn't go for a swim this time, but I'm going to get back to that soon as well. View of the Golden Gate Bridge from over my shoulder The transit ride—SF MUNI 54 to BART to San Francisco MUNI 30—was a piece of cake as always. The video below shows part of the route as seen from the bus window. I just now realized that I copied my opeining into the video twice. You didn't imagine it. Sorry about that :) I stopped for lunch at the Buena Vista I...

SKM QSOs 2026-01-08

 Project TouCans and kitchen window antenna are continuing to work well during straight key month! This is just a quick update. The rig layout can be seen in the video below.

First Day of SKM

 I made eight QSOs on my first hour long straight key month shift operating as K3Y/6! Points of note: I'm still operating five watts from the kitchen window in San Francisco. The ' shiny F2 ' cutoff was not disproven. The critical frequency between San Francisco and Utah did go below 7,750 kHz and there was only one QSO that went east of Louisiana out to New York. That happened when the fof2 value was about 8200 kHz. Does the Data Fit with ND7K in Arizona? I noticed that while Utah had disappeared again, I was still being spotted in Arizona at 01:00 UTC. Looking at the fof2 values to the spotting station, ND7K revealed that this spot conformed to my evolving rule of thumb. The midpoint fof2 is at about 8,000 kHz at the time, so above 7,750 kHz. Note for future use: The rig's freuqncy/fof2 = 14.0574/7.750 = 1.8138 The factor is for use with this figure.

FM Modulation Explained by Army Signal Corps Video

  FM modulation is so elegant it almost feels like a magic trick. After finally watching a 1940s U.S. Army Signal Corps training film, I realized just how simple frequency modulation really is—both on transmit and receive. Seeing the LC tank, limiter, and discriminator explained visually made everything click. Even better, that understanding immediately paid off in a modern, practical way: fixing an overly aggressive CW sidetone in my video QSLs using nothing more than an audio limiter. I finally understand FM modulation and it's so simple I'm amazed it wasn't developed first. I found an old US Army signal corp video that describes how both FM transmit and receive work. Audio Modulation I had not understood that modulating the transmit frequency was this simple. It all makes sense now that I see it, but I hadn't considered how simple this could be. The video demonstrates the use of an LC tank circuit to  generate the required RF. By placing a a condenser mic in p...

Great Propagation from Cibola National Forest Near Albuquerque

 I made a run to New Mexico a few weeks ago. I took the chance to attempt POTA activations from Ciblola National Forest, Lincoln National Forest, and a few other places I'll talk about later this week. My first activation in Cibloa National Forest the day I arrived in Albuquerque was by far my most successful in terms of raw QSO count. Having just arrived in town, I of course made my way to Blake's Lottaburger for a green chili cheeseburger. I've been trying to reduce my food intake a bit so I ordered an itsaburger as opposed to a lottaburger. (Seriously. It's an excellent naming scheme, no pun intended.) Next, I made my way out to Simms Park. The park is operated by the city of Albuquerque, but it's completely contained within the boundaries of Cibola National Forest, US-4514 , so voila. I taped the Project TouCan's vertical antenna on its carbon fiber support mast to a wooden railing post and got to work. I've found several references warning not to u...

Maintaining Scene Continuity with Sora-2

 We're working on a promo video for our smartphone-based CW practice app. We had great luck last week using the sora-2 app to create B-Roll footage for the Gladych Files . This week, I'm hoping to make an entire scripted trailer for the CW app using sora-2. There are issues though. The first one is that while the sora app has a storyboard feature, (at least the one I can access this week), the API does  not. It does however allow you to pass in reference images to bridge scenes. That's pretty cool, and seems to work. I'm working on  a Python script to wait for bridging images between clips. That's worked out ok.  The real issue, so far, has been sora-2 moderation. Profanity and Real-Person Filters You cannot pass the image of a real person, (even one sora-2 invented), between clips. Moderation stops it every time. ( Moderation is what sora-2 calls its engine that decides if it's able to make your video at all.) This is what set off a cascade of moderatio...