Motorola Sse 5000 6881094c12 A Manual

6881094C12-ANovember 11, 2004
Radio Description: Notations Used in This Manual 1-5
1.6 Notations Used in This Manual
Throughout the text in this publication, you will notice the use of note, caution, warning, and danger 
notations. These notations are used to emphasize that safety hazards exist, and due care must be 
taken and observed.
NOTE:An operational procedure, practice, or condition that is essential to emphasize.
CAUTION indicates a potentially hazardous situation which, if 
not avoided, might...

November 11, 20046881094C12-A
1-6Radio Description: Notations Used in This Manual
Notes 

Chapter 2 Theory of Operation
This chapter provides a detailed circuit description of the SSE 5000 transceiver and VOCON boards. 
When reading the theory of operation, refer to the appropriate schematic and component location 
diagrams located in the back of this manual. This detailed theory of operation can help isolate the 
problem to a particular component.
The SSE 5000 radio is a dual-mode (digital/analog), microcontroller-based transceiver incorporating 
a digital signal processor (DSP). The...

November 11, 20046881094C12-A
2-2Theory of Operation: Mode of Operation
2.2 Mode of Operation
This section provides an overview of the radio’s receive and transmit operation in the analog mode.
2.2.1 Receiving
When the radio is receiving (see Figure 2-2), the signal travels from the antenna connector to the 
transceiver board, passing through the antenna switch and the receiver front-end. The signal is then 
filtered, amplified, and mixed with the first local-oscillator signal, generated by the...

6881094C12-ANovember 11, 2004
Theory of Operation: Mode of Operation2-3
2.2.2 Transmitting
When the radio is transmitting, microphone audio is passed through gain stages to the CODEC, 
where the signal is digitized (see Figure 2-3). The CODEC passes digital data to the DSP, where pre-
emphasis and low-pass (splatter) filtering are done. The DSP passes this signal to a digital/analog 
converter (DAC), where it is reconverted into an analog signal and scaled for application to the 
voltage-controlled...

November 11, 20046881094C12-A
2-4Theory of Operation: Power Distribution
2.3 Power Distribution
This section provides a detailed circuit description of the power distribution of the SSE 5000 radio.
In the SSE 5000 radio, power (B+) is distributed to two boards: the transceiver (RF) board and the 
VOCON board (see Figure 2-4). In the case of a secure radio, B+ is also supplied to the encryption 
module. 
Figure 2-4.  DC Power Distribution—UHF Radios
Power for the radio is provided through a battery...

6881094C12-ANovember 11, 2004
Theory of Operation: Power Distribution2-5
even when the On/Off/Volume knob has been turned to the off position, power remains on until the 
microcontroller unit (MCU) completes its power-down, at which time the radio is physically powered 
down.
2.3.1 DC Power Routing—Transceiver Board
Connector J1, the B+ assembly, connects the battery to the transceiver board. Two capacitors 
provide protection against momentary breaks at the B+ connector due to contact bounce when the...

November 11, 20046881094C12-A
2-6Theory of Operation: Power Distribution
Table 2-4 lists the supply voltages and the circuits that use these voltages.
Table 2-4.  VOCON Board DC Power Distribution
Supply 
NameOutput 
Vo l ta g eSupply TypeUnprogrammed 
Output VoltageCircuits Supplied
UNSW_B+ 9 to 6 Vdc
7.5 Vdc 
nominalBattery N/A VCC5 input
Mechanical switch
Power switch (FET)
Secure module
SW_B+ 9 to 6 Vdc
7.5 Vdc 
nominalBattery N/A VSW1 input (GCAP)
Audio power amplifier
Side connector
SW_B+ to...

6881094C12-ANovember 11, 2004
Theory of Operation: Transceiver Board2-7
2.4 Transceiver Board
The transceiver (XCVR) board performs the transmitter and receiver functions necessary to translate 
between voice and data from the VOCON board and the modulated radio-frequency (RF) carrier at 
the antenna. The transceiver board contains all the radio’s RF circuits for the following major 
components:
• Receiver
• Transmitter
• Frequency Generation Unit (FGU)
2.4.1 Interconnections
This section describes the...

November 11, 20046881094C12-A
2-8Theory of Operation: Transceiver Board
2.4.1.3  Antenna Ports
Antenna port J101 is a hot launch connector that interfaces to the antenna connector that is part of 
the control top. This interface provides the launch mechanism for the antenna. Antenna port J102 
provides RF to the accessory RF connector on the back of the SSE 5000 radio. This port provides 
RF energy for tuning purposes, as well as RF for a public safety microphone.
2.4.1.4  Serial EEPROM
The serial,...