brainwagon

I got home fairly late last night, and wasn’t up to any serious radio activities, but I did activate my WSPR beacon on 40m, and let it run. This morning, around 8:00AM local time, I was treated to a pretty good haul of DX spots especially from VK4 land. I had spots from VK4ZW, VK4YEH, [...]

This morning as I was heading out the door, I scanned my bookshelves for something that I could read during my lunchbreak. Much to my astonishment, I saw this book: Yes, that’s right: a copy of Wes Hayward and Doug Demaw’s classic Solid State Design for the Radio Amateur. I’d been looking for this thing [...]

Here’s the gang I work with at Pixar Animation. This was taken with the incredibly low budget technique of snapping a picture, moving the camera, and snapping another one. Of course, a couple of us moved in the interim, but thanks to the judicious work of Reid, who carefully stitched and offset various bits, it [...]

Steve has an interesting post entitled “Golden Rule and Imagined Worlds” on his blog. It’s an interesting post, suggesting that transparency and equality are the basis for a good club. I’m not sure I disagree, but I am going to take a different tactic, and it will be of the following form: how much “organization’ [...]

Bill is building an FETer (Transceiver Made with One FET) as published in Sprat by G3XBM. I don’t get Sprat (but should), but you can get the design off this web page. A very simple, truly minimal design. It’s like a haiku constructed from solder. I have some MPF102s in my junkbox. I might just [...]

I’m not 100% obsessed (more like 98%) with radio topics: this morning, I found this link on Hack a Day which provided a link to several articles having to do with TEMPEST. I’ve blogged about TEMPEST before, but for those who haven’t heard of it before, it’s a way of eavesdropping on electronic signals by [...]

Got a quick recording of the PRISM satellite, launched on the 23rd, as it came over my location. It was booming in, very fast Doppler. Here’s a recording and a quick spectrum of it, click on the image to get the spectrum of the 2 minute mp3 recording. MP3 of the Japanese PRISM satellite on [...]

Goofing around while watching Battlestar Galactica (which incidently is one of the most depressing, soul-less, unfun thing to watch that I can imagine) and decided to look up George Dobbs’ QRP harmonic lowpass filter design, and see if I could get it to analyze using ngspice. I picked his design for 30m, and created the [...]

Here’s a nifty PDF on QRP transmitter design. It looks like it might have been cribbed from one of Doug Demaw’s books (which you should buy if you are interested in this stuff), but it’s just a few pages long, and is quite practical. I think I’m actually getting to the point where I understand [...]

Okay, I’ve been reading some of my variou sources on amplifier design including EMFRD and the ARRL Handbook, and decided to try to test my understanding of them by coding up a simple common emitter amplifier, and then testing the model by plotting out the voltages using ngspice, the open source version of the popular [...]

Need to make a quick and dirty schematic drawing? Try the Klunky Schematic Drawing page.

This morning I awoke to find that Pixar’s Wall-E had been nominated for an incredible six Academy Awards! Best Animated Feature Film of the Year Achievement in Music Written for Motion Pictures (Original Score) Achievement in Music Written for Motion Pictures (Original Song) Achievement in Sound Editing Achievement in Sound Mixing Original Screenplay Pixar’s short [...]

I was digging around information on common emitter amplifier design, and encountered this link which seemed quite helpful. Digging around the All About Circuits webpage, which seems to be a very useful online reference. It helped me understand the presentation that I’ve been reading in my copy of Hands-On Radio Experiments. More on that soon. [...]

I don’t speak about politics on this blog very often. Frankly, I don’t find politics itself to be very interesing: it is a sphere of human discourse that I find all too obsessed with appearance over substance, and expediency over justice. While this might form the basis of a faintly amusing reality TV show, it’s [...]

Well, you can’t do better than an article by the legendary George Dobbs, G3RJV. The circuit that he has closely resembles the oscillator that I just built, with a few distinctions. A Universal VXO by George Dobbs G3RJV The general topology is the same, but the resistive voltage divider that feeds the base of the [...]