Half-wave. There are two main variants of this antenna, both of which are very effective and are
recommended where long range and all-round coverage are required:
1. The half-wave dipole consists of two quarter-wave whips mounted in line vertically and fed in the
centre with coaxial cable. The bottom whip takes the place of the ground plane described previously.
A variant is available using a helical instead of a whip for the lower element, giving similar
performance with reduced overall length. This antenna is suitable for mounting on walls etc. but for
best results should be kept well clear of surrounding conductive objects and structures (ideally >1m
separation).
2. The end-fed half wave is the same length as the dipole but consists of a single rod or whip fed at the
bottom via a matching network. Mounting options are similar to those for the quarter-wave whip. A
ground plane is sometimes used but is not essential. The end-fed arrangement is often preferred
over the centre-fed dipole because it is easier to mount in the clear and above surrounding
obstructions.
Yagi. This antenna consists of two or more elements mounted parallel to each other on a central boom.
It is directional and exhibits gain but tends to be large and unwieldy – for these reasons the yagi is the
ideal choice for links over fixed paths where maximum range is desired.
Please note: Using a Yagi or other gain antenna with the TX1 will exceed the maximum radiated
power permitted by UK type approval regulations. It can be used in the UK only in conjunction with
the RX1 receiver.
For best range in UK fixed link applications use a half-wave antenna on transmit and a half-wave or
Yagi on receive, both mounted as high as possible and clear of obstructions.
The above antennas may be obtained from several sources in the UK, for example:
R W Badland Ltd
Unit 3
Providence Street
Lye
Stourbridge
West Midlands
DY9 8HN
England
Tel. +44 (0)1384 423160
Fax +44 (0)1384 423958 / 895051
info@badland.co.uk
www.badland.co.uk
Renair Antennae Ltd.
11-15 Chase Road
Park Royal
London NW10 6PT
England
Tel: +44 (0)20 8965 3001
Fax: +44 (0)20 8965 5773
sales@renair.co.uk
www.renair.co.uk
Radiometrix Ltd., TX1 & RX1 Data Sheet
page 13
RADIOMETRIX [ RADIOMETRIX LTD ]
