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.

Continue reading “Portable S-band Ground Station Update”

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, a super low noise preamplifier from Kuhne and GNU Radio software.



ATX-1080 Technical Overview

The ATX-1080 is a small multi band vertical antenna covering 80 – 6 meters, including the WARC bands. It is very similar to the MP-1, a major difference being that the coil is placed at the bottom. Also, the MP-1 has a continuous tuning on the coil while the ATX-1080 has fixed taps for the connections. I bought the antenna at the German Wimo who even supplies some extra documentation along with the original paper.

Continue reading “ATX-1080 Technical Overview”