A rabbit ears antenna is what is known as a half-wave dipole antenna. The electromagnetic field that
propagates the transmitted RF (Radio Frequency) signal induces a standing wave into the antenna.
The magnitude of the standing wave (seen as signal strength) is dependent on many factors, one of which
is the total length of the antenna relative to the wavelength of the RF signal.
To get the highest received signal strength, the point at which the signal is coupled to the receiver
should be at the one-quarter wavelength point; this means the total length of the antenna should be
one-half wavelength. For a 183MHz signal, this translates to approximately 32 inches. The actual
tip-to-tip distance will usually end up somewhat larger due to the spacing of the "ears" on the
antenna mount and not having the "ears" exactly perpendicular relative to the signal source.
To determine signal wavelength from the frequency, use the following formula:
wavelength = c / f
where:
c = the speed of light = 11802852677 inches/sec
f = frequency (in Hz); 1 MHz = 1000000 Hz