User's Manual

mandated by its category and frequency band. See Base Radio Service Help > Service Screens > Alignment
Screens in the CSS Online Help for the alignment procedures and mandated intervals. The transceiver option card
is available in two categories:
- OCXO (Oven Controlled Crystal Oscillator) – operates at 0.1 ppm and is inclusive to temperature and
aging. The OCXO Transceiver Option Card is available in 700/800 MHz, UHF R1/R2, and VHF frequency
bands.
- TCXO (Temperature Compensated Crystal Oscillator) – operates at 1.5 ppm, of which 0.5 ppm is
allocated to temperature, and 1.0 ppm is allocated to aging. Reference precision with the TCXO is traded for
lower power consumption. The TCXO mandates shorter maintenance intervals. The TCXO transceiver option
card is available in UHF R1/R2 frequency bands. The TXCO is only available for non-simulcast conventional
systems.
Transceiver Control Board
The main operating software for the base radio is loaded in the XCVRs control section. As the main manager for the
base radio, the XCVR control board provides operational control over the other station modules. It handles three types
of information flow, in the following ways:
• Serves as a gateway between the network and RF functionality, by distributing the RF payload to and from the
network.
• Supports operational and diagnostic functions with digital control data (for example: site information, channel
assignments, and identification numbers for call processing).
• Ensures the flow of other network management configuration information.
Figure 6: Transceiver Control Board Information Flow on page 64 shows the information flow through the
transceiver control and RF sections for trunked and conventional operation.
Figure 6: Transceiver Control Board Information Flow
Transceiver RF Board
In addition to DC power conversion/regulation, the XCVR RF board provides circuitry for the following exciter and
receiver functions.
Exciter
The exciter on the XCVR RF board provides the transmitter functions for the base radio. The exciter circuitry
generates a low-level, modulated RF signal that passes to the power amplifier. It supports various modulation types as
well as bandwidths up to 25 kHz, through software programming.
The exciter also provides a controlled output power level to the power amplifier.
64 | GTR 8000 Base Radio Theory of Operation
Send Feedback | November 2013 | 6871024P71-A
Applicant: Motorola Solutions
Equipment Type: ABZ89FC5810B / 109AB-5810B
Exhibit D (Permissive Change)