- 11 -
The top support hole may also be used for rope to install it as an inverted-V (
Figure 16
).
Figure 16 –
Inverted-V Dipole – Tower Side Arm Installation
Tower side arm Universal Mounting Plates and Saddle Clamps are available from DX Engineering.
Single Band Center Fed Half Wave Dipole
When building a single band coaxial cable fed HF dipole antenna, you may easily use the formula
L = 468/F
to determine the overall length of the wire (L in feet, F in MHz). The formula takes into
account the end-effect of the antenna wire to give you the overall length of the wire portion.
As an example, using the formula L = 468/F, the overall length of a halfwave dipole for 3.800 MHz
would be L = 468/3.800 or 123.2 feet. Cut the overall length of the wire to 125 feet or more to
include the extra length for tuning, then cut that in half to provide two dipole legs – each 62.5 feet
long – for attachment to the Center-T and feedline (
Figure 17
).
Use this theoretical formula length as a starting point to cut the wire, leaving about one foot extra on
each dipole leg for wire fastening and fine tuning adjustment to allow for anomalies and
environmental effects in your particular installation. Longer length dipole legs may be required for
Inverted-V antennas.
DXE-ANTW
-(
-75 ft.
,
-150 ft.
,
-300 ft.
,
-500 ft.
,
-1000 ft.
) #14 Insulated Antenna Wire is specially
manufactured for use with the
DXE-UWA
kits.
Figure 17 - Example: 3.800 MHz Overall Length cut to 125 Ft.
Leg 1 = 62.5 Ft.
Leg 2 = 62.5 Ft.
Overall length plus some extra for wire fastening & tuning
Longer length dipole legs (up to 2 feet longer) may be required for Inverted-V antennas.
