Specification
The Dual Beam Pro is a non-resonant horizontal dipole antenna
with capacity loading end elements. Aerospace alloy is used for
the elements and the fasteners and clamps are galvanised for
excellent corrosion resistance.
Overall span of main rotatable element
Overall span of end elements
Turning radius required
Total weight including clamp and transformer
Support mast diameter range
Maximum peak envelope power 20m - 6m
Maximum peak envelope power 40m & 30m
5.0m
2.5m
2.6m
4.0kg
32 - 50mm
1000W
600W
This antenna requires an ATU to minimise the reflected power.
For 40m and 30m operation, the ATU built into most modern
HF transceivers is unlikely to have a su
ffi
cient matching range
and an external ATU will be required.
Alignment
The Dual Beam Pro may be mounted on a mast rotator or pre-
aligned in the preferred directions of coverage. The diagram
below shows the antenna aligned to beam maximum energy
East and West.
Note: this diagram is
indicative and is not a
plot of the radiation
pattern
2
Assembly
1. Insert the GRP rod through the section of the mast head
support clamp but do not tighten the clamp at this point.
2. Fit the main elements onto
the ends of the GRP rod and
align the bolt holes. Ensure
that the capacity hat securing
bolts are facing upwards
before inserting the 4 x 35mm
bolts and fitting the serrated
nuts to the 2 outermost bolts.
3. Fit the 2 connection
leads to the matching
transformer and o
ff
er up
the assembly to the 2
innermost bolts. Fit the
serrated nuts finger tight.
4. Slide a capacity hat element
through the hole in the outer
end of a main element section.
Centralise the capacity hat
element using the alignment
marks and tighten the
securing bolt by no more than
1/2 turn.
Fit the plastic end caps and repeat step 4 for the other capacity
hat element.
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