How
can I make a wire Ham Radio Antenna?
General
Information
When making an antenna, the
frequency you use directly determines the antenna's length and size. The
higher the frequency, the smaller the antenna. A typical formula used to
calculate the length of a half wavelength antenna in free-space is as
follows:
λ (1/2 wavelength antenna
in Feet) = 492 / Frequency (Mhz)
This is why the police and fire
department's use the Very High Frequency (VHF) and Ultra High Frequency (UHF) bands. The antennas are
smaller and can be installed on police cars and fire trucks, and small hand
held transceivers can be used.
High Frequency
(HF) & Medium Frequency (MF) Antennas
The most common HF and LF
antennas used by ham radio operators when first starting out are very in
expensive. The ham radio HF band covers the 3 MHz to 30 MHz and the MF band
covers 300 KHz to 3 MHz frequency range. These HF and MF antennas can be
made using wire and other support materials already available in many homes.
The wire antenna types are as follows:
-
Dipole
-
Inverted Vee
-
Vertical
-
Wire Beams
Here is free antenna design
software for making your own
wire yagi beams and
verticals by VE3SQB.
More advanced ham radio stations
include directional beams and support towers. These will not be addressed in
this section.
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