Wednesday, November 10, Pete MI3EPN reported that he heard what sounded like FM transmissions on the lower end of the HO-68 / XW-1 linear transponder and it didn’t sound like ham radio operators making contact over a satellite. It was an interesting coincidence because I could remember that I have seen some FM-like signals while I was recording HO-68 on Tuesday evening but I thought it was some local interference.
Technology
Technology articles and blogs written by Alexandru Csete OZ9AEC.
Switching from the 90 cm to 7 meter dish
Here is a recording of mounting the KU LNC 5659 C PRO downconverter on the 7 meter dish. It took about 20 minutes.
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.
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
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
First Impressions of the Arrow II Antenna
I heard about the Arrow II Satellite antenna quite some time ago and even seen a lots of videos about it on YouTube. Unfortunately, whenever I look for an opportunity to get one, I couldn’t find it anywhere in Europe. Until recently, when I learned by a coincidence that Antenna Warehouse is also shipping them … Read more
Test Driving WebSDR
I was playing around with WebSDR the other night. It was really fun – next I’ll try to record myself on 80 or 40 meters 🙂 Watch in HD resolution.
Apollo 11 Anniversary Event on AO-51
On July 20, AMSAT will mark the 40th anniversary of the first manned lunar landing with a special event on the AO-51 amateur radio satellite. During evening passes in the U.S. and Europe, AO-51 will transmit a message commemorating the event. The message will be transmitted on the 435.300 MHz FM downlink and will contain … Read more
Ariane 5 rises above ESA’s Kourou tracking station
What a beautiful photo! Ariane 5 V188 with Herschel and Planck on board rises above ESA’s 15m ESTRACK tracking station at Kourou, French Guiana, just after liftoff at 15:12 CEST, 14 May 2009. Click for full size image