Service Manual

Page 1.13
2 ~ SERVICE PHILOSOPHY
1. INTRODUCTION
1.1 GENERAL
The SRP9100 series of FM portable radio transceivers are designed for conventional PMR and Trunked
operation in VHF and UHF radio systems.
The transceiver is available in three functional variants. The variants are as follows:
Description PMR/Trunked
Portable Transceiver with no Keypad SRP9120
Portable Transceiver with Keypad SRP9130
Portable Transceiver with Keypad and Graphic Display SRP9130-Plus
1.2 SCOPE
This manual provides technical specifications, description and servicing details for the SRP9100 series of
portable radio transceivers together with the related accessories.
Unless specifically stated otherwise, the text and illustrations refer to all versions in the series.
1.3 D
ESCRIPTION
The design concept utilises wide band analogue techniques for RF transmit and receive circuitry with digital
signal processing of analogue or digital modulation and demodulation. Electronic tuning is used throughout
the portable to eliminate manual tuning and level adjustment.
A Digital Signal Processor (DSP) and a Programmable Gate Array (PLA) are used with other dedicated
devices in the SRP9100 to perform the following functions under software control:
• Frequency Synthesis of all operating frequencies.
• Modulation and demodulation of 10/12.5/20/25kHz FM signals on a per channel basis.
• Modem functionality for specified data modulation schemes.
• Filtering, pre-emphasis, de-emphasis, limiting, compression, muting, CTCSS, Selcall or any other
frequency or level dependent signal modification.
• Serial communications with the Control Ancillaries, Field Programmer and Alignment Tool.
• Tuning Control data for Tx and Rx.
The SRP9100 Transceiver comprises a rugged cast internal lightweight alloy chassis that houses two
printed circuit board assemblies and provides all heatsink requirements. The battery slides into the chassis
where it is securely locked via two high impact clips. Release is achieved by depressing a latch on the
battery. The chassis is enclosed in a high impact polycarbonate ABS plastic case that retains the speaker,
keypad and display.
The buttons, connectors and antenna are sealed against moisture and dust ingress by gaskets around keys
and display or bungs in the case of the external connectors.
The main PCB assembly comprises a multi-layer board containing all the RF and control circuitry. The
display or man-machine interface (MMI) board is connected via a miniature connector to the main board. A
flex strip connects the speaker and microphone also to the main board. Provision is made for optional plug-
in accessories in the radio. (eg. for encryption, P25, etc.)
Several battery capacities and technologies are available to suit the endurance requirements of the portable
application.
The antenna is connected to the radio via an SMA plug that is mounted into the radio chassis. The antenna
flange provides it with additional rigidity when seated on the radio body.