brainwagon

I ordered a little HamCan kit about a week ago. It’s a little QRP CW transceiver produced by the Four State QRP kit. Today, I spent about an hour assembling it, and fired it up. This is just a short status report: it’s acting a bit wonky. The tone sounds pretty rough, the frequency seems […]

I’ve had a couple of conversations with Tom over the last couple of days, and they were curiously related. He just got back from a trip to Ireland where he visited Newgrange, a prehistoric tomb mound in County Meath. It actually predates the Great Pyramid at Giza, and predates Stonehenge by a thousand years. One […]

I like to read the Programming Praxis website. Every post challenges you to write some simple programs to boost your skill, akin to finger exercises for a musical instrument. Today’s challenge was an interesting which intrigued Charles Babbage: creating word squares. I spent about 10 minutes writing one in Python that worked rather well: here […]

I’m old. I learned to program as a teenager in the 1980s. Back then, we learned to program on small microcomputers. These machines weren’t very powerful, but they had a neat feature: they were self-hosted. In recent years, a large variety of small microcontrollers have become popular. Many of these have capabilities far in excess […]

Eldon, WA0UWH was inspired by my recent experiment with Tatsuo Kogawa’s micro transmitter, and decided to build his own. Unlike my rather crude (but surprisingly effective) lashup on some copper clad board, Eldon designed a tiny 0.5″x0.8″ board, etched it and used surface mount components to finish it. Very nifty, and totally dwarfed by the […]

I’m doing a bit of website management. This might result in some minor unavailability of my website: hang in there, I’ll be back. Update: I appear to be up and running again on a new server. Go ahead and send me some send me an email if you note any troubles.

I learned to program as a teenager back in the 1980s, starting as most of a generation of future computer professionals did. I had an Atari 400 at home, and learned to program using the most popular language of the day: BASIC. There were lots of magazines like COMPUTE! and Creative Computing that included program […]

Yesterday’s video showed a very fussy version of Tetsuo Kogawa’s 1 transistor FM transmitter, which worked after a fashion, but which seemed really squirrely. Almost any motion of anything caused the circuit to behave rather badly as capacitance changed, and I picked up a considerable amount of hum. Today, I rebuilt the circuit onto a […]

Tetsuo Kogawa’s circuit is pretty well documented, but not in conventional schematic form. I decided to enter it into LTSpice to see what it could make of it, and decided to go ahead and put the schematic online here, with perhaps a few comments: I’ve set this up more or less as I built the […]

I’ve received two requests for information about my “video production pipeline”, such as it is. As you can tell by my videos, I am shooting with pretty ugly hardware, in a pretty ugly way, with minimal (read “no”) editing. But I did figure out a pretty nice way to add some watermarks and overlays to […]

A couple of days ago, I mentioned Tetsuo Kogawa’s MicroFM transmitter, a simple one transistor FM radio transmitter. Tonight, I decided to put it together on an experimenter’s breadboard. I didn’t have the 2SC2001 transistor that Tetsuo Kogawa used, so I just dusted off one of my $.10 2N3904 transistors, and dug the rest of […]

I’m going to divert myself from my normally safe topics of conversations, and briefly wander into a matter of politics, because Representative Jesse Jackson Jr. has been getting a lot of press lately for his astonishingly stupid remarks about the iPad costing American jobs. Jesse Jackson Jr.: The iPad Is Killing American Jobs. Sigh. First […]

In digging around for small AM radio schematics (I’m more interested in AM than FM), I ran across Tetsuo Kogawa’s site on building the “simplest” FM transmitter. It’s actually pretty cute, and has just a single transistor, a few resistors and caps, and a coil that you can wind yourself on the threads of a […]

Back in 2000, I was intrigued by the various demos that I saw which attempted to implement real time raytracing. I wondered just what could be done with the computers I had on hand, without using any real tricks, but just a straightforward implementation of ray/sphere and ray/patch intersection. As I recall, I got two […]

The problem with working some place with lots of intelligent people is that it is increasingly hard to maintain one’s sense of superiority. Today, I tip my hat to Inigo. He has a very cool demo here, where he creates a program by creating and editing a small image in photoshop, saving it as a […]