It’s been more than a year now that I last posted an update about using my Asus Eee PC 701 for hamradio. To be honest, my Eee PC has been more or less idle ever since. Back in August 2008 I have decided that I need a newer and better OS on it than the Asus/Xandros that it came installed with. I tried a few one every now and then but without any satisfactory results. Until now…
Gpredict in the Linux Journal
. I noticed today January 2010 issue of Linux Journal has amateur radio as it’s main topic. In fact, the whole front page is a big Amateur Radio and Linux headline. There are three articles about amateur and several great ham radio apps for Linux are described in these articles: Fldigi, Xlog, Xastir, Gpredict and … Read more
SO-67 Sumbandila on Nov 29, 2009
Today, there were two good passes of SO-67 over Europe with the amateur radio transponder activated. Watch in high resolution. Watch in high resolution.
Coming up in Gpredict 1.2
After fixing several major and minor bugs in Gpredict 1.1 it was time to look at what new cool features version 1.2 should include. Fortunately, there is a nice list of feature requests from users that have been accumulated over time so all I had to do was to pick one and start working on … Read more
Mounting a TV antenna with a bulldozer
My parents needed a new TV antenna for UHF because the old one was broken. So that’s what we did this nice and sunny Sunday. Unfortunately, we do not have a ladder that is long enough so we had to improvise with my dads bulldozer 🙂 Watch in high resolution
Fun with WebSDR and Fldigi
Tonight I had some fun with Fldigi connected to Web SDR. I could actually listen to and decode digital ham radio traffic on the 80 and 40 meter bands without using a radio or antenna. The way I achieved it was by configuring Fldigi to capture its data using the built-in microphone and turn the … Read more
GNU Radio Projects
This page provides an overview of the various projects and experiments I am or have been doing with GNU Radio and the Universal Software Radio Peripheral (USRP). GNU Radio is a free, open source software development toolkit that provides the signal processing runtime and processing blocks to implement software defined radio. The USRP provides a … Read more
Do it yourself HF2V
Often I receive emails from people asking for the dimensions of the HF2V elements because they want to build one themselves. Well, here are the dimensions for all the coils and capacitors. Good luck with your experiments!
Portable S-band Ground Station Update
I made good progress with the portable S-band ground station this week.
I took the receiver to the OZ7SAT lab to measure its performance. Using the USRP+DBSRX and no LNA we could easily detect a -132 dBm CW signal with modest FFT integration (fraction of a second) in a GNU Radio spectrum scope. Using the LNA we could go down to about -138 dBm, i.e. an improvement in SNR of 6 dB. These figures were measured at an SNR ~5 dB. This is excellent, but please note that this is not real “sensitivity” in the traditional sense because we were not demodulating or decoding the signal. We were simply integrating the spectrum for a fraction of a second to detect the presence of the signal. The measurements were done by sampling a 250 kHz wide spectrum.
New vLog: Introducing the S-band Ground Station Project for LRO/LCROSS Reception
In this new video blog I am introducing a new project that has kept me occupied for a few weeks now: A low cost S-band ground station for receiving signals from NASA’s lunar spacecrafts LRO and LCROSS. More info at Receiving LRO and LCROSS. Based on the Universal Software Radio Peripheral (USRP) with DBSRX daughterboard, … Read more