brainwagon

I’ve been meaning to do a quick post about podcasts that I listen to that are related to ham radio, just in case there are some among you who may not have heard about them, or who may have heard about them but haven’t given them a try. Here’s a list of what I listen […]

Maker Dino Segovis has a website called hackaweek.com where he tries to do a hack a week, streaming his construction via uStream, and then posting youtube video and details on his blog. This week, he decided to build a copy of Alexander Graham Bell’s PhotoPhone in celebration of the 131st anniversary of its unveiling to […]

Huzzah! I’ve been wanting to get a Funcube Dongle Pro for some time, but they have been in short supply. Today, a fresh batch went on order, and this time: success!! The Funcube Dongle Pro is a cool little software defined radio that plugs a USB port, and receives from 64Mhz to 1700Mhz. I am […]

Today, I had to do some yardwork, so I dusted off the weed whacker, and climbed the back of the hill to chop down some high grass. At the end of an hour, I was about 40% done (I’ll do the rest next weekend) but sneezing and coughing from the liberated pollen and dust. So, […]

My silly experiment with an LED communicator naturally led me to looking up more complex (and better engineered) versions of the same kind of circuit. There are now cheap LEDs that can emit a watt or more of energy, and produce a prodigious amount of light. It seems like an area which is ripe for […]

Dave, NM0S and designer of the HamCan, a kit that I previously assembled, but had some difficulty with nicely contacted me via email today so ask if he could be of help. I’m pretty sure that whatever the issue is, it’s my own fault, but hopefully with some patient help from Dave I can figure […]

Next weekend is our Maker Faire here in California, but there was just a Mini Maker Faire in Toronto, and it looked like there was some awesome stuff. Check out these neat video: Makers: Mini Maker Faire Toronto from Ryan Varga on Vimeo.

Kindred spirits Atdiy and whisk0r over at the tymkrs blog were playing around with inductors: They demonstrated that inductors can generative large inductive spikes: in spite of the fact that there coil is charged by a relatively low voltage, when you sharply disconnect a coil from a charging voltage, it generates a large voltage spike […]

In my previous post, I mentioned that I had programmed a machine that used core memory. It was the DEC 1091 we had at the University of Oregon back in the mid 1980s. I was overcome with a feeling of nostalgia, and decided to try to look up how to install TOPS-10 onto the simh […]

I always think it is good to follow up a practical build of an electronic circuit with some simulation to try to learn some of the underlying design principles. LTSpice is a great circuit capture/simulation system which runs on Windows, but also runs pretty well under Wine. I was a bit intrigued by the behavior […]

I was bored, but not quite up to the challenge of debugging my existing radio project, or starting a new one. I idly began winding some wire onto a FT-37-43 toroid, and then remembered that I had never constructed a “Joule Thief”, a simple little circuit that allows you to light an LED using just […]

So, over the weekend I assembled the HamCan, and got some pretty wonky performance. I’m going to go through it all again and see if I can figure out why the receive performance is so bizarre, (loose connection? poor adjustment?) but it got me thinking that part of the issue is that typical PCB construction […]

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 […]

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.