6
2.2 Assembly of boom
The square-boom consists of two parts which have to be assembled by the two coupling pieces
that are already installed at one side of the boom. For each coupling piece 4 screws are needed.
The screws have to be tightened finally not before the parts of the boom really
fit
to each other
perfectly.
2.3 Construction of the elements
For the element-to-boom brackets 4-cornered plates are used and the insulation of the elements
is done by 2 (driver platform = 4, see below) special plastic tube holders.
According to the diameters of the elements there are 2 plates with 25mm (S20 / R20), 2 plates with
20mm (S15 / R15) and 2 plates with 16mm (S10 / D10) tube holders.
The driver element platforms are a bit longer. On them you find a pair of tube holders left and right
plus the bottom half of a tube holder in the middle to reinforce the centre of the driven element
which is split with the insulator.
The middle sections of the elements have to be fixed
exactly centred
on the plates (orientation =
black middle line on parasites / insulator middle piece on driven elements which finally has to sit
centred in the pre assembled bottom half of the support tube holder). For that the element middle
sections have to be put in to the tube holders (only concerning the driven elements the tube holders
at one side have to be opened for this process). Then the screws of the tube holders have to be
tightened solidly
. The screws of the driver middle sections divided with the insulators have to
point
straight upwards
.
Next the other element sections have to be assembled. Insert the following sections in the previous
sections with their side which has two drill-holes
equal in size
. The tubes have to be put in until
the drill-holes of both sections overlap perfectly (concerning the outer 12mm tubes of the driven
elements and the outer 12mm tubes of R20 the
middle one
of the three drill-holes has to be
chosen).
Then the corresponding screws (25mm tube = longest screw / 20mm tube = middle size screw /
16mm tube = shortest screw) have to be pushed through
from the side of the enlarged
drill-hole
of the previous segment. On the opposite side the washers have to be inserted and the self
securing nuts have to be screwed on and
tightened solidly
(hold the screw heads with the included
special screw-driver against turning, the screw heads dive into the enlarged drill-hole, see picture
page). This method results in an extremely solid mechanical connection and rattle sounds inside
the segment overlaps are totally avoided.
By this way of assembling the required lengths of the sections and the element halves are achieved
automatically.
While mounting the elements pay attention that all screw heads show
upwards
.
This also counts for the screw heads in the distance insulators of the bent 12mm sections for the
20m band.
Keep in mind that the elements hang below the boom. Therefore the screw heads have to be on
the same side of the elements where the plates are located at.
2.4 Attaching the elements to the boom
The elements fixed on the plates have to be mounted on the
underside
of the boom at the marked
positions while the connecting screws of the boom should remain horizontal. The square boom
makes a straightening of the elements unnecessary.
After complete assembly the tips of the bent 12mm sections for the 20m band have a distance
between each other by 18 cm.
They have to be connected by means of the distance insulator and hereby will be stabilized in the
same moment.
Summary of Contents for OB6-3M
Page 10: ...9 ...
