| Electricity and
Magnetism > Electromagnetic Radiation |
DCS# 5N10.60 |
DIPOLE
RADIATION
-
APPARATUS
VCR
with
videotape
|
202-09-B |
| monitor |
202-alcove |
RF
amplifier
|
202-alcove
|
pair
of folded dipole antennas
|
202-alcove
|
DESCRIPTION
Set the
VCR and the transmitter antenna a few meters away from the
monitor and
its antenna.
Show that the reception deteriorates
if
the
antennas are not parallel to each other, demonstrating that
electromagnetic waves are transverse and polarized.
Demonstrate
standing waves by holding the receiver antenna 1/4 wavelength in
front
of the metal chalkboards to improve the strength of the
signal.
The signal strength varies with location in general because of
reflections
off all the metal in the room.
NOTES
- Connect the
amplified VCR RF
output to an antenna. The second antenna is
connected to the antenna input of the monitor.
Sending and
receiving channels should be set to 4.