Tait TB9300, Installation And Operation Manual, Page: 84 / 138

84 Installation
TB9300 Installation and Operation Manual
© Tait Limited March 2016
H-Band
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 5MHz 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 H-band reciter covers one of the following frequency
sub-bands, depending on the model:
■
H1 and HC - 400 to 440MHz
■
H2 - 440 to 480MHz
■
H3 - 470 to 520MHz.
Each sub-band uses the same helical filter (shown in Figure 5.4 below).
The bandwidth of the helical filter is approximately ±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
“Connecting a Networked PC to a Base Station” on page 56 .
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.
4. Set the reciter to the new receive frequency.
Figure 5.4 Identifying the H-band receiver front end helical filter
H-band helical filter