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TB9400 Installation and Operation Manual
Installation
85
© Tait Limited March 2015
5.4.6
Tuning the Reciter
This section also applies to receive-only reciters.
B-Band Reciter
Before the base station is installed on site, you may need to tune the
receiver front end. The receiver front end requires tuning if the receive
frequency is shifted more than 2MHz away from the previously set
frequency, or the RSSI level of the new frequency is more than 1dB lower
than the RSSI level of the previously set frequency.
receiver front end. The receiver front end requires tuning if the receive
frequency is shifted more than 2MHz away from the previously set
frequency, or the RSSI level of the new frequency is more than 1dB lower
than the RSSI level of the previously set frequency.
The receiver in the B3-band reciter covers the 148 to 174MHz frequency
band. This is split into two sub-bands: 148 to 159MHz and
159 to 174MHz.
band. This is split into two sub-bands: 148 to 159MHz and
159 to 174MHz.
Each sub-band has its own helical filter (shown in
below) which
is electronically switched in or out of circuit depending on the frequency
programmed into the reciter. The bandwidth of these helical filters is
approximately ±1.5MHz.
programmed into the reciter. The bandwidth of these helical filters is
approximately ±1.5MHz.
To check the RSSI level and tune the receiver front end (if required), follow
these steps.
these steps.
1.
Remove the reciter from the subrack and reconnect the system
control bus cable to power up the reciter.
control bus cable to power up the reciter.
2.
Log in to the reciter and select Monitor > Interfaces > RF Interface.
For information on connecting directly to the reciter, refer to
For information on connecting directly to the reciter, refer to
Figure 5.3
Identifying the B-band receiver front end helical filters
B3: 148 to 159MHz
B3: 159 to 174MHz