I have previously written about interference from FM stations on the HO-68 linear transponder. Now it appears the other satellites with linear transponders also suffer from local FM traffic by people who haven’t got a clue that they are transmitting in the satellite uplink segment of the 2 meter band.
Here is a new recording showing an updated Gqrx receiving the FO-29 amateur radio satellite using the Funcube Dongle. Previous recordings used an early version of Gqrx. It was a very quiet pass, most notable thing was probably the Russian and Spanish hams using FM. They probably don’t have a clue that their signal comes over a satellite transponder. Another video recording focusing on the FM transmissions during this FO-29 pass is available here.
With both the frequency controller and FFT plot widgets in place gqrx was ready for the first on the air tests. The video below shows the first reception of the AO-27 amateur radio satellite during orbit 92436 and 92437, using the Funcube Dongle receiver that I use for portable space communication.
Inspired and impressed by the performance of the Funcube Dongle during my initial tests, I have decided to perform some more thorough tests using a minimalistic setup consisting of a laptop running Gpredict and Quisk SDR software, the Funcube Dongle and an Arrow II hand held satellite antenna.
Today I have spent some time trying the Funcube Dongle with Quisk SDR. The setup procedure was quite painless and the results very satisfactory: Using an Arrow II hand-held yagi connected directly to the FCD I could receive the HO-68 CW beacon with very good SNR.
It looks like AMSAT is going to launch a new satellite! ARISSat-1 – the successor of SuitSat-1 – is ready to be launched on Progress-41P heading to the International Space Station on Friday, January 28, 2011. It will be deployed into its own orbit during EVA 27 currently scheduled for February 16. Once in orbit, it will slowly decay and eventually burn up in the Earth’ atmosphere. SuitSat-1 decayed after 7 months in orbit and that’s also a likely life time for ARISSat-1.
So, why is ARISSat-1 cool and why should we care?
Before getting my hands all dirty with adding UHD driver to Quisk, I decided to take it for a test drive using some pre-recorded samples. I have used a 250 ksps recording of the HO-68 / XW-1 linear transponder downlink that I have recorded on November 9, 2010 using the USRP and the RFX400 daughterboard.
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.