brainwagon

I didn’t get a chance to watch the online webcast, but the SpaceX launch of flight 4 of their Falcon 1 launch vehicle managed to reach earth orbit, becoming the first privately developed vehicle to do so. They don’t have video up yet, but when they do, I’ll try to link it. Congratulations to the […]

I’m still playing around with GMT to generate some maps. I’m not sure I’ve really got it figured out, but here is an attempt to draw a world globe with some of the great circles that connect me to the various stations that have received my WSPR beacon messages. Addendum: Robert pointed out that I […]

Perhaps I’ll see some of you there.

Yesterday, I took the wife and the future daughter-in-law to Travis AFB for their airshow. It was a blast. Lots of cool planes, culminating in a nice show by the Air Force Thunderbirds. I snapped a lot of photos, this one probably being the best.

Courtesy of BibliOdyssey: Early Microscopes, a collection of very cool etchings showing, well, early microscopes.

Hellschreiber is a method of sending text over radio. It basically is a kind of primitive fax machine: it sends each character as a 7×14 matrix of dots. If the receiver hears a signal, it plots a dot, otherwise it plots a space. Each character is scanned left to right, bottom to top, and are […]

Well, last night, conditions on 40 and 30 were frankly pretty terrible. I tried to get a couple of VE3s to pay attention to me on 40m PSK31, but it was not gonna happen. I was lamenting this on the IRC freenode.net #hamradio channel, and NM5DV decided to give PSK-31 a try. He was running […]

Conditions have been really bad on 30m. I haven’t had any luck at recording any beacons at all in the MEPT subband, so I was bored. I went to this page and found a recording of some QRSS signals: Receiving QRSS My software renders this out as this, clearly showing the two FSK shifted morse […]

Well, the bands were really dead this evening, so I decided to try to see if I could find some software that might be useful. I sometimes monitor various beacons, and the NCDXF beacons are the most famous. There is luckily this neat little program: IBP software for Linux/Unix available for Linux that can help […]

Marching pass us in the graduation parade. Couldn’t be prouder.

YouTube – Adam’s Airman Run, July 31, 2008 (Higher Quality) Today we got to see Adam for the first time in six and a half weeks. He’s been off for Basic Military Training in the Air Force, and tomorrow will be his graduation ceremony. Today, we saw him take part in the Airman’s Run. Around […]

While digging around for information on how to observe radio echos from meteors, I stumbled across this fascinating link about using reflections from the NAVSPASUR system (a government system to find and track satellites in orbit) using equipment that isn’t beyond the capacity of amateurs to create. Very, very cool. NAVSPASUR Title Page

Today, I decided to code up a little test of something that I’ve been meaning to do for quite some time: to write an implementation of a tunable bandpass filter. The algorithm is actually pretty darned simple, at least if you have a couple of pieces of code available. Let’s say you want to create […]

DJ1YFK suggested this site for info on small magnetic loop antennas. I should check this out. Magnetic Loop Antennas, Magnetic Loop Info, How to Build A Magnetic Loop, W2BRI Loops

Just stashing a link to some papers on VLF radio that came across a mailing list. Index of /~talves/VLF