User manual

Page 22 915U-2 Wireless I/O
Page 22 User Manual
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 cable 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.
Figure 6 -Wrapping Coax Connections
Stretch to elongate sealant tape
while wrapping over the connection
For proper UV protection Electrical
Tape should then be wrapped over
the Vulcanising Tape
Maximum Gain per region
Country
Max Gain (dB)
USA / Canada
6
Australia / New Zealand
0
Europe
0
Typical Antenna Gains
Part No
Antenna
Gain (dBi)
DG900
Whip with 15‟ (5m) cable
-2
CFD890EL
Dipole with 15‟ (5m) cable
0
SG900-EL
5dBi Collinear (3dBd)
5
SG900-6
8dBi Collinear (6dBd)
8
YU6-900
6 element Yagi
10
YU16-900
16 element Yagi
15
Typical Coax losses (900 MHz)
Part No
Cable Type
Loss (dB per 30ft / 10m)
CC3-SMA
10‟ (3m) Cellfoil Coax
-1dB
CC10-SMA
33‟ (10m) Cellfoil Coax
-3dB
CC20-SMA
66‟ (20m) Cellfoil Coax
-6dB