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TB9400 Installation and Operation Manual

© Tait Limited April 2014

This section also applies to receive-only reciters.

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. 

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. 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. 

To check the RSSI level and tune the receiver front end (if required), follow 
these steps.

1.

Remove the reciter from the subrack and reconnect the system 
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 

3.

Feed a signal at the currently tuned receive frequency and at a level 
of –80dBm into the reciter’s RF input. Check that the RSSI reading 
on the RF Interface page is –80dBm ±1dB. Note this reading.

148 to 159MHz

159 to 174MHz