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Is There Such a Thing as a Homebrew System?

 There's been a lot of talk about what is and isn't homebrew lately. I started hearing the all-in-good-fun contention around the Soldersmoke DC Receiver Challenge . A few days back, the conversation wandered over to the comments section of a HackaDay post. In that post, I found the following quote from The Tao of Programming :  "When designing an operating system, the programmer seeks the simplest harmony between machine and ideas." While it's cobbled together from modified kits, TouCans, suspended in its dipole beneath a Golden Gate Fortune Cookie Factory rain shield, will always sit in my heart as a manifestation of "the simplest harmony between machine and ideas" That makes me wonder if there should be a catetory known as a homebrew system. Sure, TouCans has kits, but they're modded to fit the application. They're also powered and controlled by a homebrew Darlington array buffered momentary contact relay (keyer) and a latching relay (power),...
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Pico-W Pico2-W Radio Module Released as Independent Product

 Raspberry Pi released the Raspberry Pi Radio Module 2 today. It's the same wireless module supporting both WiFi and Bluetooth that's used for the Pico W and the Pico 2 W, but it's packaged as a standalone module . Photo of Pi Radio Module 2 from release announcment I don't know if we'll wind up using this module on Project TouCans, but the external antenna you can see on the right-hand side of the module abovoe has been enticing at various points during the project. I know that extending the antenna would violate the conformance and RF certification that the module provides, but Project TouCans isn't a commercial product yet anway, so... There are games we can play with just the module itself though. The first of which would be to move from a Pico-W to a Pico and move the processor module inside TouCans, leaving only the wireless module on the ouside of the device.  TouCans Current Setup with Pico-W on the Outside This should make the whole rig more rugged, bu...

File this under Property Tax Assessment District Ghost Stories

 So, this is kinda cool and kinda fun! Found this ghost story all about property taxes, assessment districts, Japan, and AI via Maggie Appleton . Ghost hunter photo by Hamilton Carter from the San Francisco Highlands glorious ghost haunting grounds of yore.

Two Good Ham Radio-ish Academic Journal Articles

 I do a lot of work with maps of the F2 layer of the ionosphere. I found two good articles, (so far), this week that I wanted to pass along. The first has to do with the ionosphere itself and how signals propagate through it. The Department of Commerce book , ( here's the older 1948 version ), on the ionosphere that I frequently quote and more frequently use cites a number of formula and diagrams without a whole lot of explanation. I finally checked out the references this week and found that much of the information I use from that book—including the figure below—comes from this more information-dense paper by Newbern Smith. The second paper hits on the topic of quaternions—one of my perrenial favorites—in  relation to rotations in video games. How did I find it? Using ChatGPT to prototype mapping apps again, of course. I wanted to find what squares on a spherical map of the Earth a QSO path traveled through. ChatGPT suggested susing something called a slerp . Wondering if t...

Low Current Kinda High Voltage QRP Tube Transmitters

 I just saw a heartening post with respect to the gang's and my quest to see if Agent Sonya could have built her own radio rig. Pete, one of the presenters on Soldersmoke even mentions W1REX in the post in conjunctions with this transmitter schematic : Rex is better known in these parts as the ham that produces RockMite and Tuna Topper kits that populate the innards of Project TouCans. Getting back to Agent Sonya , and also to safety, I was heartened to see Pete mention a supply that had occurred to me for plate voltage and current: nine-volt transistor batteries. Gone forever, apparently, are the B cells of yore, but we can definitely string together 9 volt cells. I wandered if there were issues with this type of supply I'd missed. There aren't! The post and the circuit above also answered a question I'd often wondered about with respect to keying tube circuites. That MPSA92 looks pretty hefty what with its 300 volt rating. It is and it isn't. the maximum curren...

QRP, Locked by Rocks, and the Waterfall Display

 N2CQR mentioned the waterfall being handy for QRP in that other operators can find your rock-locked signal on the ham radio bands.  In addition to the use-case pointed out by Bill , when operating Project TouCans in locations where there's an available internet connection, I've used SDR waterfalls to my advantage in a few other ways: 1. I can get more immediate feedback than the Reverse Beacon Network. On the West Coast, the Utah SDR can see our signal during most of the day. We can find out immediately if Project TouCans is working at all. 2. I rarely have zero-beat issues with TouCans. The contained RockMite's receiver is very wide, so I can hear a lot on either side of the frequency the rig works on. There is one big issue though. The crystal oscillator for transmit has found its home near 14057.4 MHz. The receive bandpass, however, is happiest at 14057.9 kHz. Especially when there's a crowd, the waterfall display from Utah helps me to determine if the loudest sign...

New! GloTEC F2 Data as Map Images with Tooltips

 Sometimes you need a 3-D visualization of data, and sometimes you don't. I just posted a page  with foF2, hmF2, and MUFD(3000km) map images. All the maps are updated to the latest available data when you open or refresh the page. Map values are available—via tooltips—by hovering your map over the portion of the map your interested in. These maps contain the same data displayed in the 3-D Cesium Ion map . Please let me know what you think. All constructive feedback is welcome!