K8-14. Radiowaves - Standing Waves In An Antenna

Purpose

To show standing waves in a dipole antenna.

Equipment

Radio wave transmitter with fluorescent tube.

Images

Description

Electrons oscillate in a half-wave dipole antenna such that a standing wave is set up along the antenna with voltage antinodes at the ends of the antenna and a current antinode at the center. A fluorescent lamp can be used to sense the distribution of potential along the dipole, as seen in the photograph. Touch one end of the tube gently on the antenna while holding the other end. The bulb will light near the voltage antinodes.