RF200/500 user manual
4
2.0 RF200 Broadband antenna
The broadband antenna will allow the user to detect and measure radiation over the
frequency range 30MHz to 1GHz.
This is shipped in a ‘knocked-down’ form to ease packaging and to minimise the
potential for damage in transit. Assembly is straightforward but must be done with
care.
The basic design of the antenna consists of a central main beam, itself comprising two
parallel aluminium sections spaced apart by insulators. Equal length pairs of stainless
steel rods form the antenna elements, these mounted on the main beam in order of
length, the shortest at the end from which the output lead is attached. An insulating
mounting block provides attachment for the stand with facilities for horizontal and
vertical mounting. The non-metallic stand allows adjustment of antenna height and
direction.
2.1 Antenna assembly (see fig 1)
1. The aluminium alloy elements are secured to the central beam using the M4 bolts
and washers provided. An M4 hex driver is also included to facilitate assembly. These
elements are mounted in equal length pairs with the shortest at the end of the central
beam where the output cable is attached. There are two copper crinkle washers with
each bolt. Ensure that one washer is under the bolt head and the other is under the
antenna element. Tighten the bolts until the crinkle washer is flat. Do not overtighten
as this may distort the beam. Alternate the element direction as shown in the diagram
so that for each side of the central beam, the elements alternate up, down, up,
down...etc
. until element 9 which is out-of-sequence and is mounted same side as
element 8
. Element 10 is alternate to element 9 as shown in Fig 1.
3. The number of elements (10 pairs) should match the number of hole pairs along the
central beam.
4. A pre-drilled plastic block is supplied to form a central mounting block and pre-
amp support. This is screwed to both beams using the supplied nylon screws.
