User's Manual

Page 16 E2 Wireless I/O
At 900MHz the maximum net gain of the antenna/cable configuration permitted is
Country Max. Gain (dB)
USA / Canada 6
Australia / New Zealand 0
Europe 0
At 900MHz the gains and losses of typical antennas are
Antenna Gain (dB)
Dipole with integral 15’ cable 0
5dBi Collinear (3dBd) 5
8dBi Collinear (6dBd) 8
6 element Yagi 10
9 element Yagi 12
16 element Yagi 15
Cable type Loss (dB per 30 ft / 10 m)
RG58 -5
RG213 -2.5
Cellfoil -3
The net gain of the antenna/cable configuration is determined by adding the antenna
gain and the cable loss. For example, a 6 element Yagi with 70 feet (20 metres) of
Cellfoil has a net gain of 4dB (10dB – 6dB).
Connections between the antenna and coaxial cable
should be carefully taped to prevent ingress of
moisture. Moisture ingress in the coaxial cable is a
common cause for problems with radio systems, as it
greatly increases the radio losses. We recommend that
the connection be taped, firstly with a layer of PVC
Tape, then with a vulcanising tape such as “3M 23
tape”, and finally with another layer of PVC UV
Stabilised insulating tape. The first layer of tape allows
the joint to be easily inspected when trouble shooting
as the vulcanising seal can be easily removed.
Where antennas are mounted on elevated masts, the
masts should be effectively earthed to avoid lightning
surges. For high lightning risk areas, surge suppression
devices between the module and the antenna are recommended. If the antenna is not