Motorola Mototrbo - 1.6 Theory of Operation

Parameter Specifications
VHF UHF
Spurious Harmonics and Emissions -36 dBm < 1 GHz, -30 dBm > 1 GHz
Audio Distortion < 1%
Audio Response Per TIA/ETSI
FM Hum and Noise 25 kHz/12.5 kHz -50 dB/-45 dB
FCC Identifier ABZ99FT3094 ABZ99FT4096
FCC Emission Designators 11K0F3E, 16K0F3E, 7K60FXD, 7K60F7D,
7K60FXE, 7K60F7E, and 7K60F7W
Industry Canada
• IC certification/registration number
• IC model number
• Tx/Rx Frequency range
109AB-99FT3094
SLR 5000-VHF
Tx: 138–174 MHz
Rx: 138–174 MHz
109AB-99FT4096
SLR 5000-UHF
Tx: 406.1–430 MHz and
450–470 MHz
Rx: 406.1–430 MHz and
450–470 MHz
All specifications noted above are in accordance to their respective TIA603D, ETSI EN 300 086, and
ETSI EN 300 113 standards unless otherwise noted.
1.6
Theory of Operation
The SLR 5000 series repeater provides the radio frequency (RF) link between the repeater and the
subscriber radios.
The repeater acquires inbound signals via its external receive (Rx) antenna and then amplifies, filters
and demodulates the signals into data or voice packets. From that point, the data is either forwarded to
the repeater’s transmitter to subscriber radios, and/or the data is delivered via a wired interface for
distribution to networked repeaters, consoles, or other networked infrastructure.
The SLR 5000 series repeater consists of a Modem, Power Amplifier (PA), Front Panel and Power
Supply (PS). These modules are also known as field replaceable units (FRU).
• The Modem module is comprised of three subsystems, which are the Receiver subsystem, Exciter
subsystem, and Station Control subsystem. At a high level, these subsystems are further explained
as follows:
- The Receiver subsystem is a dual heterodyne Receiver which receives the RF signal from the
subscriber’s transmitter. It then converts the resulting final intermediate frequency (IF) from an
analog signal to that of a digital word in IQ signal format. Finally, the Receiver delivers the IQ
signal, via the SSI bus, to the Station Control subsystem for demodulation. Additionally, the
Receiver subsystem also provides for its own metering and diagnostics via software, as well as
self-contained calibration (no field tuning is needed for the Receiver subsystem).
- The Exciter subsystem converts a two-port base band data signal, sent over the SSI bus from
the Station Control subsystem, to an analog signal representation. The analog signal is then
modulated with a low power RF transmitter carrier that is generated by the Exciter subsystem.
The power modulated RF carrier is then amplified and delivered to the PA at an intermediate
level of approximately +36 dBm for further amplification. The Exciter subsystem and PA
constitute the transmitter of the SLR 5000 series repeater. Additionally, the Exciter subsystem
also provides its own metering and diagnostics via software, as well as a self-contained
calibration (no field tuning is needed for the Exciter subsystem).
Chapter 1: SLR 5000 Series Repeater
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