7.
Generally the balun is installed in one long loop. Attach balun to the block connectors and tighten
gently
using a 7/16" end wrench. Form the balun coax close to the boom and secure with cable ties
(snug but not crushing or kinking the coax).
8.
Install the 8
-
32 x 1/4” set screws (internal Allen head
-
tool supplied) into the SHORTING BARS.
Slide the bars onto the 3/16” rod driven element tips and the 1/4" Feed Block Rods. Position the
Shorting Bars as specified on the DIMENSION SHEET: the distance given is between the outer
face of the Feed Block and the inner face of the Shorting Bar. Align the bars and rods with each
other and tighten the sets crews. NOTE: the shorting bar dimensions are different on the
OPTIONAL circular switched driven element.
9. Now attach all the cables. The two medium length cables are the 1/2 wave baluns. The long coax
cable goes to the front driven element. And the short cable goes to the rear driven element. Tighten
the connectors lightly with a 7/16” end wrench.
REMEMBER CENTER MOUNTED ANTENNA MUST BE PLACE ON A FIBERGLASS OR OTHER
STRONG, NON CONDUCTIVE MAST AND THE FEEDLINES MUST RUN OFF THE REAR OF
THE ANTENNA. THIS PREVENTS THE CIRCULAR FIELD OF THE ANTENNA FROM BEING
DISTORTED BY A METALIC MAST OR METALIC FEEDLINE.
10. For center mounted antennas, the boom to mast plate is normally mounted as close as possible to
the balance point (with feedline or a temporary equivalent attached). For rear mounted antennas,
use the boom length provided behind the reflector element. Keep mounting plate at least 1" from
any element. Secure plate with two U
-
bolts and the stainless nuts and lock washers provided. DO
NOT OVER TIGHTEN. Additional U
-
bolts and stainless nuts / lock washers are provided for
mounting the antenna to your mast. THIS COMPLETES THE ANTENNA ASSEMBLY.
11. For optimum performance, mount antenna high and in the clear.
Always
use high quality coax and
connectors. Old, corroded, or poor quality materials can SERIOUSLY affect VSWR, gain, and
pattern. If possible, test the antenna, connectors and feedline BEFORE installation. At 6' in height,
the antenna will exhibit performance
approaching
the specifications. If it doesn't, check feedline
and connectors for continuity and shorts. Check antenna shorting bars, element placement and
length, against Dimension Sheet.
12. MOUNTING AND STACKING INFORMATION
Rear mounted antennas
can generally be mounted in any polarization to any type of mast,
conductive or non
-
conductive.
Center mounted antennas
can also be mounted in any polarity.
However, a mast or crossboom
in
-
line (parallel) with the element plane must be non
-
conductive.
Anything conductive in the
element plane will disrupt the pattern and reduce performance (even the feedline). When a non
-
conductive mast or crossboom is in
-
line with elements, route feedline away at right angles to the
elements and reattach at least 6" beyond element tips. Fiberglass is the recommended material for
a non
-
conductive mast or crossboom because of it's strength and weather resistance.
Stacking:
See the Dimension Sheet for stacking separation dimensions.
1. All driven element blocks MUST be oriented to the same side of boom.
2. All boom
-
to
-
mast plates MUST be mounted at the same point on the boom.
3. Feed / phasing lines MUST be of equal electrical length or, ideally, multiples of 1 wavelength in
order to maintain equal phasing in the array.
M
2
ANTENNA SYSTEMS, INC.
4402 N. Selland AVE., FRESNO, CA 93722
(559) 432
-
8873 FAX: 432
-
3059
400CP30A ASSEMBLY MANUAL
