I’m always amazed when things actually work. So you can imagine my amazement when I actually got the demo shown in the Make: Magazine video below to work.
Diana, KC2UHB, used her lightbulb/antenna combo to demonstrate the principle of directional antennas by using a Yagi as her transmitting antenna. I didn’t have a Yagi handy, so I used one of my home-made J-pole antennas.
Because the J-pole isn’t directional, I obviously couldn’t use it to demonstrate directionality, but it worked quite nicely to demonstrate the principle of polarization. All I had to do was to position the receiving antenna so that it was parallel to the J-pole and the light was nice and bright. Then, I rotated the antenna until it was perpendicular to the J-pole. The light got dimmer and dimmer until eventually you couldn’t see it emitting any light at all. Rotate it back to perpendicular and the bulb burned brightly again.
I think I’ll try to make a video of this down at the Museum this Saturday.