GDA-1600 16-Channel Controller
Instruction 5700-9001
50
method is a good idea if there is a large amount of interference from another system close
by transmitting vertical polarity.
An important mounting tip – if a Yagi has drainage holes in the dipole element, do not
mount the antenna with the drainage.
8.5.3
Mounting Near Other Antennas
Avoid mounting your network’s antenna near any other antenna even when the other
antenna is transmitting on a different radio band. High RF energy of the transmission
from a close antenna can “deafen” a receiver. This is a common cause of problems with
wireless systems.
Because antennas are designed to transmit parallel to the ground rather than up or down,
vertical separation between antennas is a lot more effective than horizontal separation. If
mounting near another antenna cannot be avoided, mounting it beneath or above the other
antenna is better than mounting beside it. Using different polarity to the other antenna (if
possible) will also help to isolate the RF coupling.
8.5.4 Coax Cables
If a coax cable connects to the antenna via connectors, it is very important to
weatherproof the connection using sealing tape. Moisture ingress into a coax cable
connection is the most common cause of problems with antenna installations. A three
layer sealing process is recommended – an initial layer of electrical PVC tape, followed
by a second layer of self-vulcanizing weatherproofing tape, with a final layer of electrical
PVC tape.
Allowing a drip “U loop” of cable before the connection is also a good idea. The loop
allows water to drip off the bottom of the U instead of into the connection, reduces
installation strain and provides spare cable length in case later the original connectors
need to be removed, the cable cut back and new connectors fitted.
Avoid installing coax cables together in long parallel paths. Leakage from one cable to
another has a similar effect as mounting an antenna near another antenna.
8.6
Surge Protection
a
nd Grounding
Voltage surges can enter the GDA-1600 via the antenna connection, power supply
connection, connections to other equipment and even the “earth” or “ground” connection.
Surges are electrical energy following a path to earth and the best protection is achieved
by “draining” the surge energy to earth via an alternate path. Wireless devices need to
have a solid connection to earth via a ground stake or ground grid if the soil has poor
conductivity. Solid connection means a large capacity conductor (not a small wire) with
no coils or sharp bends. All other devices connected to the GDA-1600 need to be
grounded to the same ground point. There can be significant resistance between different
ground points leading to very large voltage differences during lightning activity. Many
wireless units are damaged by earth potential surges due to incorrect grounding.
It is very difficult to protect against direct lightning strikes but the probability of a direct
strike at any one location is very small. Unfortunately, power line surges and
Summary of Contents for GDA-1600
Page 21: ...Instruction 5700 9001 GDA 1600 16 Channel Controller 21 Figure 3 10 Configuration Menus ...
Page 28: ...GDA 1600 16 Channel Controller Instruction 5700 9001 28 Figure 4 2 Main PCB ...
Page 36: ...GDA 1600 16 Channel Controller Instruction 5700 9001 36 Figure 4 7 Analog Output Board ...
Page 38: ...GDA 1600 16 Channel Controller Instruction 5700 9001 38 Figure 5 2 System Diagnostic Options ...
Page 53: ...Instruction 5700 9001 GDA 1600 16 Channel Controller 53 ...
