User Manual
MT-4E VHF & UHF Receiver & Transmitter Instruction Manual
IM08-MT-4E-TXRX Project 1106
23
RADIO SYSTEM
CONFIGURATIONS
REPEATER
The MT-4E series Receivers and Transmitters may be congured in a repeater conguration. 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 conguration 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 software. 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 is transferred over the Radio Interconnect Cable directly to the
Transmitter or is 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 conguration 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.
NOTE: The transmitter is not to be operated as a repeater under an existing base station license.