brainwagon

On the softrock40 mailing list, somebody mentioned the 2N2/6 Transverter, which is a 6m transverter for use with a 40m transceiver. It’s not completely trivial, but it’s not hideously complex either. I’m becoming more interested in 6m, so it seems like archiving this for my later consumption might be useful. My FT-817 already is a […]

Well, this weekend is “Field Day”: one of the big contest weekends for amateur radio. Basically hams go off grid, travel to campgrounds and the like, and operate from there. It was perhaps supposed to indicate some kind of emergency preparedness, but really, it’s just an excuse for a contest and a bit of public […]

Learning about turbo codes has been on my list for a long time. Here’s a tutorial that looks like it might be helpful.

All the fun I’ve been having with tracking satellites has made me want to create a nice little database of all the frequencies they use. This page seems like it had everything you need: All satellites list update

Last night I was redoing my Python script that did Doppler tracking. There was a very low (max elevation under fifteen degrees) pass of SEEDS II that came up while I was making changes, so I went ahead and used it to record some of its Morse telemetry. The signal was pretty weak and intermittent, […]

In an earlier posting, I presented a recording that I did of the new Russian satellite Yubileiny, also designated RS-30. I finally found my spectrogram code, and made a picture of the resulting recording. It’s kind of big, but click the thumbnail below if you want to have a peek: The image consists of 27 […]

Well, by the time I got home tonight, there was going to only be a single low pass of the Yubileiny satellite to the west out over the Pacific ocean, but I decided to give it a try anyway. It’s maximum altitude for this pass was about 16 degrees. I started this recording pretty much […]

The Russians, in commemoration of their 50th anniversary of their launch of Sputnik, the first artificial satellite, commissioned a small satellite called Yubileiny which apparently launched in the last day. Members of the amsat-bb list have been picking up CW telemetry and some digital signals from the bird. It sounds really interesting, and includes a […]

Last night I went out with my FT-817 and a little voice recorder and tried to pick up COMPASS and CUTE on 437.275Mhz as they passed over my location. I had been told that compass sounded a bit chirpy, and indeed, there was no mistaking it when I heard it: each code element ranks up […]

Well, the satellite launch that I’ve been waiting for happened. On the first pass I thought I was setup to record the Delfi C3 telemetry, and even thought I heard a signal, but it turns out it was probably just a local birdie. The second pass of the satellite cluster was only a 9 degree […]

The news is that satellite AO-16 has gone quiet. We’ve been assured not to panic: Hello all, There are reports at http://oscar.dcarr.org/ that AO-16 has gone silent. Should this be the case, there is no cause for alarm. Over the last month AO-16 has gone from full illumination (0 minutes of eclipse) to over 250 […]

I heard via the amsat-bb mailing list that RS-22 was still transmitting telemetry, but might be interrupted by low batteries during eclipse period. I haven’t tried to listen to any Russian satellites, so I thought I’d give it a try. My satellite prediction software yielded this data for this morning’s pass: RS-22 will be visible […]

On the 28th of April, a PSLV-C9 launch vehicle will carry a bunch of tiny cubesats into earth orbit. Mineo Wakita posted a list of their frequencies to the amsat-bb, which I am reposting here. Ultimately, the Delfi-C3 sat will probably be the most interesting to amateurs (it includes a linear transponder) but getting telemetry […]

Read about a system called WebSDR on the softrock mailing list, and boy, is it ever cool. It is a software defined radio that is hooked to the internet. Multiple listeners (17 at the time I was on) can separately tune over portions of the 40m and 80m band, and have the sound streamed to […]

My excursion into nostalgia has me researching homebrew transistors and tubes. Today, G3CWI mentioned this article about homebrewing transistors on the GQRP list. The method isn’t quite as “from scratch” as I would like: it basically uses the innards of a diode to make a point-contact transistor. Something that comes a bit closer to real […]