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TRACER 2xT1 User’s Manual
61280003L2-1B
Section 2 Installation
21
Preliminary
SPREADING CODE
The spreading code for each end must be the same. The choice of operating code is selectable by the
operator or the installer. TRACER is shipped in a matched (default) configuration.
WARNING
It is possible for the spreading code to be changed remotely through the VT-100 interface from
the other end of the link. When this is performed, communications will be lost to the far end.
The spreading code will change to code “0” and communications will be lost as soon as this
change is made. If this happens, set the Spreading Code on the local unit to code “0”. The units
should regain communications as soon as the correct code is selected.
CO-LOCATING MULTIPLE SYSTEMS
When multiple transmitters are to be co-located (installed in the same equipment room or on the same
tower), it is advised to set all systems as follows:
1. If more than one system is transmitting from the same location, set the antenna polarity of
one system horizontal and the other system(s) vertical if the systems are operating in the
same frequency bands. (The antennas should be marked as to which mounting position is
vertical or horizontal.) This will provide approximately 30 dB of isolation between the
different antennas.
2. If more than one TRACER system is installed, set the co-located transmitters to the same
frequency plan (example: Plan A, Tx=2422; or Plan B, Tx=2462) and set each to a different
spreading code. This keeps the transmitters on the additional system(s) from interfering with
the co-located receiver(s).
3. If the systems are from different manufacturers, set the transmit frequencies as close as
possible with different spreading codes. Other manufacturers may not use the exact
frequency plans as the TRACER system, but keeping the frequencies close will reduce the
probability of the transmitter(s) interfering with the co-located receiver(s).
This equipment is authorized under CFR 47 Part 15.247. With this authorization by the FCC, this
equipment shall not be co-located with a similar transmitter that transmits identical information.
ANTENNA ALIGNMENT
After the transmitter power for each end has been adjusted and the BBP and RFC have been installed and
connected, the antenna should be connected to the RFC via the feedline. Verify that both antennas are
arranged on the same polarity: vertical or horizontal. The antennas should be aimed toward one another
as precisely as possible and the received signal strength indicator (RSSI) voltage measured. The RSSI
voltage is a function of the signal strength at the receiver and is used to measure the received signal
strength. RSSI varies approximately from 0 to 4 volts, with 0 volts corresponding to a weaker received
signal and 4 volts corresponding to a stronger received signal.