Amateurs have bounced signals off the moon for years and there has even been a successful attempt to reflect amateur communications from Mars. But now, a group of Texas amateurs have succeeded in obtaining echoes of their signals from the surface of the sun.
“One of the biggest problems was that we needed to make our hundred-foot dish non-reflective to sunlight, but still work with radio waves”, said team leader Wayne, W9BRJ. “Our first attempts used a normal bright aluminium dish but when we pointed it at the sun we instantly vaporised the feedpoint”. Another issue was the time taken for echoes to be detected – it takes about 16 minutes for radio signals to travel to the sun and back. “So we would make an adjustment, squirt out a signal and have time for a beer before looking for a bounce.”
The team used an ERP of 1.8 terawatts and a super-cooled pre-amplifier with a noise figure of less than -3.7dB to receive the very weak reflections.