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Description
TB9400 Installation and Operation Manual
© Tait Limited March 2015
1.5
Applications
The TB9400 is designed for operation in a Tait P25 Phase 1 or P25 Phase 2 
trunked radio network. It can operate as a single base station or as part of a 
simulcast channel group, and as a traffic channel or control channel. 
In P25 Phase 2 operation, a single TB9400 base station can provide two 
traffic channels, since each radio frequency (physical channel) provides 
two logical channels (timeslots). However, it can provide only one control 
channel, since control channels are still P25 Phase 1.
In a trunked simulcast network, the transmitters in the channel group are 
synchronized and transmit simultaneously on the same frequency. Each 
transmitter needs a highly accurate 1PPS pulse and an external frequency 
reference, so that it can time transmissions with the required accuracy. Also 
required is an NTP source that is derived from the same source as the 1PPS 
signal. This will ensure a common timestamp in logs across all units in the 
system. An external frequency reference, along with an NTP source and 
1PPS signal derived from the same GPS source, are also essential for P25 
Phase 2 operation.
The base station can be provided as a receive-only variant in systems that 
need sites to enhance the receive coverage. The reciter in a receive-only 
base station is physically unable to transmit.
The base station can be configured for Shared Channel operation, to detect 
interference on the uplink, as long as the site controller is compatible (P25 
Phase 1 only).
For more information on these applications, refer to the Help and 
appropriate Tait P25 System Manual.