ADTRAN TRACER 2xT1, User Manual

Page: 28 / 65

TRACER 2xT1 User’s Manual
61280003L2-1B
Section 2 Installation
17
Preliminary
The nominal received signal level is -60 dBm. For help in link planning, use the path loss calculation
worksheet below.
- 91 dBm (-90 dBm for 5.8 GHz) ........ Minimum Signal Power
+ _______ ............................................. Transmitter Feedline Loss
- _______ ............................................. Transmitter Antenna Gain
+ _______ ............................................ Path Loss
- _______ ............................................. Receiver Antenna Gain
+ _______ ............................................ Receiver Feedline Loss
+ _______ ............................................ Required Fade Margin
= _______ ............................................ (dBm) Transmitter Power Setting
SETTING THE TRANSMITTER POWER
The FCC specifies the maximum transmitter power that may be used for antennae of a given gain. FCC
rules Part 15, Subpart 247 allow for a maximum power of 1 watt into antennae of a gain less than or
equal to 6 dBi. For every 3 dB of gain over 6 dBi, the transmitter must be reduced by 1 dB. The
following table lists the maximum transmitter power for given antennae gains. For the 5.8 GHz band,
there is no reduction in transmitter output power required for antennae gains greater than 6 dBi.
Antenna Gain Power
6 dBi ......................................... 30 dBm (TRACER & 2.4 GHz 1 watt output option)
12 dBi ....................................... 28 dBm (TRACER & 2.4 GHz 1 watt output option)
18 dBi ....................................... 26 dBm (TRACER & 2.4 GHz 1 watt output option)
24 dBi ....................................... 24 dBm (TRACER & 2.4 GHz 1 watt output option)
30 dBi ....................................... 22 dBm (TRACER & 2.4 GHz 1 watt output option)
36 dBi ....................................... 20 dBm (TRACER standard output option)
The transmitter power is set by way of a potentiometer on the front panel of the BBP or via the
configuration page of the interface VT-100. The RFC must be attached by way of the IF cable during
this operation. Attach an RF power meter to the N-type antenna connector on the RFC, and adjust the
power by way of the potentiometer or VT-100 until the desired transmitter power is obtained. For
convenience, the transmitter power adjustment should be made before the RFC is installed on the mast.
2.4 GHZ, 1 WATT TRANSMITTER OPTION
The 2.4 GHz Tracer model is offered with a st20 dBm power output or optional 1 watt power
output option. The 1 watt option provides an add-on amplifier that is installed in the rackmount RFC
chassis. This amplifier is connected to the transmit cable of the RFC module and amplifies the +20 dBm
output power to a maximum level of +30 dBm (1 watt), factory set to +27 dBm. The output power is
proportional to the output level from the RFC module. The level is adjusted via the Baseband Processor
front panel or VT-100 terminal.
Because the 1 watt amplifier is frequency specific, the frequency plans can not be manually changed by
swapping the TX and RX cables in the RFC chassis. If a frequency reversal is required, the rackmount
RFCs will have to be relocated to the opposite ends of the microwave path. The 1 watt option is only
available for the 2.4 GHz, rackmount Tracer systems.