brainwagon

About two years ago, I spent an evening and hacked together a simple program for taking recordings of HF-FAX transmissions and converting them into image files. The other day, I thought I’d dust that code off, but I couldn’t find it. So, instead, I reimplemented it from scratch. There is an interesting bit of math […]

Wow, the Google Chart Tools api includes all sorts of interesting things you can do with a tiny bit of web programming. For instance, you can make charts or visualize maps, or even typeset nifty mathematical formulas. It isn’t hard to write little chunks of Python code that can be used to create little png […]

I don’t have the right antennas or the best setup for decoding, but I can still occasionally hear some of the more local NAVTEX stations, and using MultiPSK (capable, but man, is that one program in need of a makeover) I managed to decode some of the alerts. Without further ado: PACIFIC COAST HIGHWAY BRIDGE […]

An azimuthal map shows the compass direction for the shortest path to a given location from the place the map is centered. This can be useful to help you aim antennas. I’ve used GMT to make maps before, but if you need a custom azimuthal map for your location, try surfing over to NA3T and […]

Today is Wednesday, which means that it’s a day for trying different bands on WSPR. Today is scheduled to be 15m, which I have never tried before. I immediately saw a few RTTY stations below the WSPR sub band, which was a good sign, and two minutes later, I had my first spot, and it […]

I hooked up my MFJ antenna analyzer to my dipole, and wrote down the R and X measurements (resistance and reactive impedances) from 7.0 to 7.35Mhz. WIthout further comment, here is the graph.

While working on my Morse practice generating program that I have tentatively called mscript, I decided that I wanted to support “Farnsworth” timing: basically sending characters at one rate, but then increasing the spacing between characters and words so that the overall rate was slower. The idea (as near as I can tell, completely untested […]

A while ago, I bought an MFJ antenna analzyer, but I hadn’t really done much with it. I wanted a short, simple project over the weekend, so I decided to check out my 40m dipole. A quick sweep revealed that it was resonant off the top end of 40m, around 7.350 or so, and that […]

Bruce, VE9QRP has been experimenting with using a small Atmel controller to implement the Plan 13 algorithm that provides satellite tracking and Doppler calculations (the same algorithm that I use in my own Python code). It seems silly to drag a laptop into the field to do Doppler tuning when a couple of dollars worth […]

Allright, I’m probably the last ham on the planet who doesn’t know about this one, but just in case there is one other out there, I thought I’d give a plug to the ICQ Podcast. I found this while trying to find other podcasts for people trying to learn Morse Code. It is a terrific […]

This morning greeted me with this nice little video, where Diana Eng demonstrates the pattern generated by dipole and Yagi antennas by a simple detector consisting of a dipole antenna with a small flashlight bulb wired across the feed point: httpv://www.youtube.com/watch?v=lslHtCUSfN4 It does actually uncover one of my pet peeves: in describing the action of […]

Well, there wasn’t anything terrific on TV tonight, and I’ve had a little program kicking around in my head for a while, so I decided to set down and see if I could make some headway on it in a single evening of programming. I used to have some Morse code practice cassette tapes a […]

Tonight, I’m currently hearing station DP1POL, from grid IB59uh on 40m. Where is that, you might ask? Antarctica. He’s heard my beacon before, but I think this is the first time that I’ve received him. The distance is nearly 15,000 km. Verah nice.

The more things change, the more things stay the same: MR. B. N. BURGLUND, whose description of the wireless station at the University of Michigan, appeared in our March number, writes us an interesting letter on the part played by wireless amateurs during the recent floods in the Middle West in March. He has much […]

The early history of radio is quite fascinating, and luckily, lots of books from this early period are out of copyright and are available for free on the Internet. As an example, check out The book of wireless telegraph and telephone by A. F. Collins. This was radio in its infancy, when the use of […]