20 METER HALF SLOPER INSTALLATION
INTERNATIONAL ANTENNA COMPANY
888-268-4214 CLICK HERE FOR PRINTABLE PDF
are the proud owner of the new DOUBLE BAZOOKA HALF SLOPER ANTENNA. The
first thing to do is to consider which direction you want your maximum
signal to radiate. The antenna tends to be somewhat omni-directional;
however, the largest lobe radiates towards the direction the antenna
slopes. If you want your signal to have an easterly direction slope the
antenna from the tower towards the east. The feed point of the antenna
should be mounted to the tower between 30 to 55 feet above around.
However, the antenna can be installed at a lower height but the SWR will
be somewhat harder to get below 2:1 without the aid of an antenna
The Half Sloper antenna is recommended to be installed
from a metal tower or metal push up pole. Secure the eyehook located
above the feed point in the “T” mold to the tower or push up pole with
nylon cord thus providing a good physical mount. Securely fasten the
ground lug extending from the other end of the “T” mold to the metal
tower using a clamp or metal screw. This mounting point should be as
close the eyehook mounting point as possible. Next, extend the end of
the antenna outward and downward so the antenna forms a 45-degree angle
away from the tower. A reference point would be that 90 degrees would be
straight out from the tower.
Mount the ends at least 10 to 25
feet above the ground. The ends may be fastened with cord to poles or
whatever, using proper safety rules in safeguarding that persons, pets,
and other objects cannot come in contact with any of the elements as
shock hazards or RF burns could result.
• Whenever connecting
the ends of the antenna to an object it is recommended that a light or
medium relief “springs” with a safe working load limit of 5 lbs be
installed to compensate for any movement of the antenna or connecting
object. “DO NOT USE A TENSIONER DEVICE”.
After mounting, the
antenna connect a 50 ohm feed line such as RG-58, RG-8 or RG-213 coax to
the antenna and your transmitter. With a very low amount of output
power applied to the antenna at your desired frequency, measure the SWR.
An antenna analyzer may also be used to measure the SWR. The antenna
should exhibit an SWR of less than 2:1 across the entire 60 meter band.
The antenna is cut for the CW portion of each band from the factory so
further adjustment is optional.
If the SWR is higher than 2:1
be sure the tower is well grounded. Due to certain soil conditions
several quarter wavelength ground radials may need to be connected to
the tower base and buried under the ground away from the tower. This
will provide a better ground than a single ground rod. For more detail
see tuning instructions on the IAC website located in the information
To lower the SWR, fold the 300-ohm twin lead back on
itself ensuring it is flat on itself with no gaps equally on each side.
The fold of 12, 24, 36 or 48 inches must be done in a (single fold over
not multiple fold overs). This procedure will raise the operating
frequency of the CW portion of the band. Once the lowest SWR is obtained
tie wrap the folded end securely to retain its position. If you measure
a higher SWR, make sure that the antenna is not near or touching any
metal objects such as rain gutters, aluminum siding, metal roofs, etc.
making sure the SWR is within spec and everything is clear of the
antenna. You are ready to operate and enjoy all of the great signals
and DX contacts that this antenna offers.
We at IAC wish you the greatest DX' ing and are sure you will be pleased with your purchase.
IAC ACCEPTS NO LIABILITY FOR DAMAGE OR INJURY RESULTING FROM THE
INSTALLATION AND USE OF THIS ANTENNA.