This focussing effect is very strong with wavelengths less than the aperture of the reflector, making it particularly suitable for recording high frequency sounds such as birdsong. Schematic diagram ...

To me, this means a large parabolic reflector, a feed horn made of brass sheet, coat hanger wire, and at least for the initial experiments, an RTL-SDR dongle. I’ve done the calculations ...

Just like destroying an ant colony with a magnifying glass, there’s nothing like cooking hot dogs and roasting marshmallows with a nice parabolic reflector. Of course covering an old satellite ...

Swiss-based solar panel company Airlight Energy has partnered with IBM Research to use IBM's direct wam-water cooling design ...