MT-4E VHF & UHF Receiver & Transmitter Instruction Manual
IM08-MT-4E-TXRX-P1162
7
RadIo SyStEM
ConFIGuRatIonS
REPEatER
The MT-4E series receivers and transmitters may be configured in a repeater configuration. The
standard way of setting up a repeater system is to connect the receiver to the transmitter through a
Radio Interconnect Cable plugged into the RJ45 CNTL BUS connectors on the front panels of each
radio module. This cable routes analog and digital COR / PTT signals and LVDS Serial Data from
the receiver to the transmitter in both analog and P25 Digital mode. The Radio Interconnect Cable
may be connected directly from the receiver to the transmitter, or may be routed through a Repeater
Control Card.
A typical configuration is to set up the repeater to re-transmit an incoming signal in the same mode as
it is received (i.e., normally, you would want a received analog signal to be repeated as analog and a
received digital signal to be repeated as digital). This requires the receiver and transmitter modules to
be programmed in Mixed Mode of operation through the RSS. The repeater may also be programmed
to operate in analog or P25 Digital mode only.
Mixed Mode Repeat operation occurs as follows:
1. The receiver determines whether an incoming signal is analog or digital and asserts either the ANALOG
COR or DIGITAL COR signal line on the front panel RJ45 CNTL BUS connector. LVDS Serial Data is sent to
the RJ45 CNTL BUS connector as well.
2. The COR signal and LVDS Serial Data are transferred over the Radio Interconnect Cable directly to the
transmitter or are routed through a Repeater Control Card.
3. The transmitter senses the incoming ANALOG PTT or DIGITAL PTT signal from the front panel RJ45 CNTL
BUS connector and keys up in analog mode or P25 Digital mode. LVDS Serial Data is routed through the
transmitter for transmission.
An alternate way of setting up a repeater system is to connect the receiver to the transmitter through
an Audio Control Card or Base Controller. These control cards route analog audio and a single
COR / PTT signal from the receiver to the transmitter. This configuration is recommended for analog
repeater systems only.
The receiver and transmitter have no connection between them apart from the audio (Audio Control
Card or Base Controller only), COR / PTT signals and LVDS Serial Data lines. The transmitter does
not get any information from the receiver about which frequency or channel number to key up on.
The receiver and transmitter channel is determined by the state of the channel select lines and bank
select line.
